Abteilung Siedlungshygiene und Wasser für Entwicklung

Maintaining a consistent supply of feedstock for efficient bioconversion of black soldier fly larvae (BSFL) presents challenges due to the fluctuating availability of biowastes and agri-food products. To address the challenge of consistent feedstock supply for BSFL, this study investigated the influence of three preservation methods: wild fermentation, inoculated fermentation, and acidification on agri-food by-products applied over three storage durations (1, 7, and 14 days), evaluating their impact on BSFL bioconversion, and feedstock nutrient and microbiota composition. The preserved feedstocks were characterized for gross nutrient, sugar, fermentation metabolite, and bacterial community analyses. All feedstock preservation methods and storage durations had a high bioconversion rate (21–25 % dry mass) and wet larval mass (170–196 mg). Notably, 7-and-14-day acidified feedstock had a significantly higher bioconversion rate compared to fermented feedstock. Acidification preserved feedstock nutrients best with only a 10 % difference compared to initial nutrient values. Fermentation produced typical lactic acid fermentation metabolites with reducing sugar contents; however, adding a lactic acid bacterial inoculum (7 log₁₀ CFU kg feedstock⁻¹) had no benefit, presumably due to the high nutrient content and existing richness in lactic acid bacteria. Preservations had little influence on Enterobacteriaceae (6.2–7.5 log₁₀ CFU g⁻¹) in freshly harvested larvae. Future research should assess the acidification and fermentation of different BSFL feedstocks and investigate the roles of feedstock pH, organic acids, and fermentation metabolites in more detail. Therefore, this study advances toward reliable and efficient insect-based nutrient recovery from agri-food by-products within the food system.

Climate change, rapid urbanization and other grand challenges increasingly force cities to rethink their urban (water) infrastructure. In particular, decentralized urban water management solutions, which can recover valuable resources close to the source are increasingly applied to remediate water scarcity, sanitation or environmental pollution challenges. Yet, although interesting demonstration projects with decentralized solutions (from here on labeled ‘decentralized UWM solutions’) are underway in several world regions, actors developing and implementing this transformative innovation are not effectively coordinating their efforts and sharing the latest knowledge. While effective technologies, business models, or regulative frameworks increasingly exist that could inform, inspire and improve similar activities elsewhere, details of local successes and failures are still (too) rarely shared or transferred across space. Drawing from experience on the mainstreaming of other transformative infrastructure solutions (like renewable energies, electric mobility or circular waste management), we posit that the global diffusion of decentralized UWM solutions has been significantly slowed down by this lack of interaction among key stakeholders, and the resulting lack of an effective innovation ecosystem.

Introduction: The Water Flow Diagram (WFD) is a novel advocacy and communication tool that presents urban water supply and management in a simple visualization. Rapid urbanization, growing populations, and the climate crisis increase the pressure on water resources, particularly in urbanized areas. The WFD aims to foster a dialogue around conflict of interests and opportunities among different stakeholders, and trigger actions toward more sustainable urban water management (UWM), as well as a water secure future.
Method: The WFD is produced from data on water abstraction, water use of different sectors, water treatment, water recycling and contamination risks. The data were obtained from government services, wastewater and water utilities, large industries, universities and reports of intergovernmental organizations. If these sources did not have data, reports from NGOs or consultants, comparable contexts, default values or expert judgements were considered. The annual water flows are presented in a Sankey Diagram. An intuitive color code highlights the flows as “problematic” or “appropriate” and points to areas where UWM practices should be improved.
Results and conclusions: The final diagrams are a concise instrument that identifies challenges of UWM in the four application cases presented in this article. Key challenges that became evident included: pollution from agricultural production, the lack of wastewater and sanitation infrastructure, high water losses in the distribution networks, water exports leading to a lack in local supply and sewer overflows during heavy rainfalls. Opportunities identified were the need to: invest in sanitation and wastewater to protect resources, create coordination bodies to align conflict of interests, and/or invest in blue-green infrastructure for rainwater retention. The WFD triggered local actions, such as in-depth discussions between relevant actors, the formation of integrated water use committees and the interest of the national ministry in Senegal to replicate the diagram for other locations. This article presents the methodology, discusses the four case studies and deliberates on the prospective use of the WFD.

This paper focuses on the critical role of integrative leadership in inter- and transdisciplinary (ITD) research programs. ITD programs have become one of academia’s responses to address contemporary sustainability challenges. Fulfilling the promise of such programs is extraordinarily challenging for all involved participants, but especially for program leaders who have to ensure that the perspectives of the involved program participants become truly integrated and that final and useful synthesis outputs are created. We present six core leadership challenges and respective strategies to address them to advance integration within ITD programs. These challenges include (1) mastering complexity and ambiguity, (2) advancing decision-making with lateral leadership, (3) ensuring responsibility and accountability, (4) setting program boundaries, (5) selecting suitable projects, and (6) dealing with misconceptions. We derived these challenges and respective strategies from both leading and studying in-depth three ITD programs focusing on sustainability issues in Switzerland. With this paper, we intend to promote awareness about the range of leadership challenges in ITD programs and provide actionable knowledge, which can support in particular fellow and future leaders, but also funders and heads of research institutions in their efforts to realize the integrative potential of such programs.

To achieve the universal target of 'safely managed sanitation' set out in UN Sustainable Development Goal 6, the world needs to increase its rate of progress, since e.g. Phnom Penh, the capital of Cambodia, currently has zero percent safely managed sanitation. One way to promote safer faecal sludge management is to shift to a more circular system with nutrient recycling, but this carries the risk of heavy metal accumulation in the environment. This study analysed the concentrations of heavy metals in raw faecal sludge from various sources and assessed the appropriateness of resource recovery and reuse in relation to the heavy metal and nutrient loads in faecal sludge. A total of 42 samples collected from sludge disposal sites in Phnom Penh during the dry and rainy seasons were analysed for heavy metals and physicochemical parameters. Mean measured concentrations of heavy metals in faecal sludge samples decreased in the order Zn > Cu > Pb > Cr > Ni > Hg > As > Cd in both seasons but were higher in the rainy season, probably due partly to inflow from stormwater drains and run-off from roads during storm events. All elements analysed were within the permissible limits for application to land according to EU standards and USEPA. However, Hg and Zn concentrations exceeded the tolerance limits for local organic fertiliser and Swedish limits for compost. Faecal sludge is thus not an appropriate fertiliser considering the risk of heavy metal accumulation in relation to phosphorus recovered. Options to avoid recirculating pollutants to the environment include upstream prevention of pollution, source separation of household wastewater fractions and use of biosolids as a soil conditioner together with other fertilisers or for soil production. Additional studies are needed on these options if sanitation stakeholders are to close the nutrient loop.

Plastic waste circularity is a priority at a global level. Sustainable development goals (SDGs) set the ways to go, and the circular economy principles underlined the 'green' strategies to be employed. However, in practice, there is still much to do, especially in developing countries, where open burning and open dumping still represent the common way of plastic waste disposal. This review aims to analyse current plastic waste circular approaches in low-middle income settings. Seven countries were selected based on the economic level and data availability from the authors, and analysed to collect and critically discuss the actions implemented at a city level. Examples of waste minimization and recycling strategies, selective collection systems and public campaigns are reported from Africa, Asia and Latin America. First, a background analysis related to physical and governance aspects of municipal solid waste management systems of the chosen settings was conducted. The assessment was focused on the treatment processes or minimization actions. Then, the applicability of the projects to achieve the SDGs was commented on. The outcomes of the research underline the need to: (1) scale up small-scale and pilot projects, (2) disseminate good practices in more low- to middle-income settings, (3) create synergies among international partners for further replications in cities. Urgent solutions to plastic waste pollution are needed. The review presented practical actions to be implemented now to boost plastic waste circularity in developing cities.

Open dumping and burning of solid waste are common practices in low-income countries. On small and touristic islands, the problem is exacerbated due to the additional volume of waste amount generated by tourists. This article presents how, using Nosy Be island in Madagascar as a case study, waste recovery and recycling can be fostered by tourism to tackle the waste challenge. About 95% of the waste of Nosy Be is openly dumped, discarded to sea or openly burned. Field analysis, interviews with local stakeholders and waste flow analysis served as methodological tools to assess the current solid waste management (SWM) system of Nosy Be. Stakeholder mapping and involvement as well as first exchange among local and international actors provided the basis to identify key practice and opportunities. Research findings highlight the importance of active participation and involvement of local partners supported by international experts, to suggest how touristic centres can serve as core of circular approaches. The article presents potential circular models to be implemented in Nosy Be, taking tourism as the entry point including the aspects of financial support, separated waste flows and the interest in 'green tourism marketing'. This case study underlines how international cooperation, touristic activities and common efforts can potentially help low-income communities improve their SWM practices.

Integrative transdisciplinary approaches to watershed management are critical for addressing intersecting social, economic, and ecological processes that shape planetary health outcomes for humans, animals, and ecosystems. These challenges are acute in watersheds like the Citarum River in West Java, Indonesia, which suffers from severe pollution due to inadequate waste management infrastructure, and is worsened by rapid urbanisation and a changing climate, which further degrades the river ecosystem and threatens lives and livelihoods. Developing a unified approach to addressing these complex problems, and responding to real world social, governance, and biophysical conditions through integrated water management, is difficult to achieve in practice. Responding to this challenge, living labs have emerged as a mode of transdisciplinary research and implementation that incorporates the expertise of diverse stakeholders in real-world settings to learn and develop solutions to complex challenges, like those faced in the Citarum River. While living lab approaches have been used widely in Western cities, there is little research that investigates its usefulness in informal peri-urban settlements. This paper presents a case study of the Citarum Living Lab, a live action research program that aims to co-develop, test, and learn from socio-technical experiments in real-world settings in collaboration with an interdisciplinary international research consortium, government, NGOs, businesses, community leaders, and residents. With the ultimate aim of revitalising the Citarum river and its surrounding environments and communities, the program engages with community experiences, existing institutional frameworks, and changing environmental conditions. This paper identifies the conditions and factors that enable and constrain a living lab approach in a vulnerable peri-urban watershed from the perspective of the research team by employing a reflexive participatory action research methodology. Place-based, transdisciplinary responses to planetary health imperatives in this context require navigation of complex, multi-level governance contexts and novel resourcing models to support applied research, implementation, and learning.

This study aimed to investigate whether separating organics depletion from nitrification increases the overall performance of urine nitrification. Separate organics depletion was facilitated with membrane aerated biofilm reactors (MABRs). The high pH and ammonia concentration in stored urine inhibited nitrification in the first stage and therewith allowed the separation of organics depletion from nitrification. An organics removal of 70 % was achieved at organic loading rates in the influent of 3.7 g_COD d⁻¹ m⁻². Organics depletion in a continuous flow stirred tank reactor (CSTR) for organics depletion led to ammonia stripping through diffused aeration of up to 13 %. Using an MABR, diffusion into the lumen amounted for 4 % ammonia loss only. In the MABR, headspace volume and therefore ammonia loss through the headspace was negligible. By aerating the downstream MABR for nitrification with the off-gas of the MABR for organics depletion, 96 % of the ammonia stripped in the first stage could be recovered in the second stage, so that the overall ammonia loss was negligibly low. Nitrification of the organics-depleted urine was studied in MABRs, CSTRs, and sequencing batch reactors in fed batch mode (FBRs), the latter two operated with suspended biomass. The experiments demonstrated that upstream organics depletion can double the nitrification rate. In a laboratory-scale MABR, nitrification rates were recorded of up to 830 mg_N L⁻¹ d⁻¹ (3.1 g_N m⁻² d⁻¹) with ambient air and over 1500 mg_N L⁻¹ d⁻¹ (6.7 g_N m⁻² d⁻¹) with oxygen-enriched air. Experiments with a laboratory-scale MABR showed that increasing operational parameters such as pH, recirculation flow, scouring frequency, and oxygen content increased the nitrification rate. The nitrification in the MABR was robust even at high pH setpoints of 6.9 and was robust against process failures arising from operational mistakes. The hydraulic retention time (HRT) required for nitrification was only 1 to 2 days. With the preceding organics depletion, the HRT for our system requires 2 to 3 days in total, whereas a combined activated sludge system requires 4 to 8 days. The N₂O concentration in the off-gas increases with increasing nitrification rates; however, the N₂O emission factor was 2.8 % on average and independent of nitrification rates. These results indicate that the MABR technology has a high potential for efficient and robust production of ammonium nitrate from source-separated urine.

Stabilization and dewatering are essential treatment mechanisms for the management of fecal sludge (FS) that accumulates in onsite containment, but reliable predictors of treatment performance are lacking. FS in Lusaka, Zambia is typically 80–98% water, which when delivered to treatment first requires dewatering, followed by stabilization of varying levels of organic matter. In addition, varying levels of stabilization are themselves observed to influence dewatering performance. Therefore, this study evaluated rapid and low-cost metrics of stabilization and their relation to dewaterability. Fourteen metrics of stabilization were evaluated based on 11 criteria in a decision matrix. Four metrics were selected to then evaluate method performance and suitability with FS samples (n = 27). The relation between stabilization and dewatering performance of collected samples were analyzed, and also following anaerobic stabilization in the laboratory. The study found that metrics based on physical–chemical characteristics such as volatile/total solids (VS/TS) and biological oxygen demand/chemical oxygen demand (BOD/COD) were not reliable for measuring FS stabilization and its relation to dewaterability. Metrics that rely on microbial activity such as SOUR (specific oxygen uptake rate) are more promising based on the consistent results obtained throughout this study.

Access to safe and affordable drinking water remains a major challenge worldwide, especially in rural areas. While passive in-line chlorination offers a promising approach for providing consistent treatment of water supplies in resource-limited settings, little is known about the factors influencing the uptake and use of these technologies. This study used a controlled pre-post intervention design to evaluate the technical performance and user acceptance of a low-cost and locally constructed chlorinator (the A’Jín) in four water distribution systems in rural Guatemala. Data sources included household surveys (N = 319) and operator interviews (N = 25), with regular monitoring of faecal contamination, pH, temperature and free residual chlorine (FRC) at reservoir tanks, taps and households. Faecal contamination was significantly reduced in water systems actively using the A’Jín device. In these systems, the share of tap and household drinking water samples with detectable E. coli decreased from 28% to 1% and 25% to 15%, respectively. Chlorine dosing consistency with the A’Jín was low, with only 24% of tap samples meeting the recommended minimal FRC threshold of 0.2 mg/L. Overall, the share of users expressing satisfaction with their water increased by 14% in the water distribution systems with the A’Jín and stayed constant for users of control systems. While the device’s low cost and simple design offered advantages over other chlorinators on the market, operators reported challenges with high maintenance needs and frequent clogging. To ensure the future success of passive in-line chlorination for small community supplies, we recommend prioritising ease of use combined with external support for addressing maintenance needs.

Bottled drinking water is among the fastest-growing options for seemingly safe drinking water in low-and middle-income countries. However, comprehensive water quality information is rarely made available to consumers. The objective of this study was to assess the physicochem-ical and microbial quality of bottled drinking water at the point of sale in Embakasi Central sub-county, Nairobi County. Using a cross-sectional study design, we assessed eight bottled water brands purchased from local retail outlets (n = 158 bottles). Laboratory analysis was con-ducted to assess a range of parameters, including Escherichia coli, heterotrophic bacteria, lead, nitrite, nitrate, fluoride, and pH. Across all bottles sampled, 12% exceeded the national standards for microbial safety (detectable E. coli) and 3% presented a high risk to health (>10 colony forming units per/100 mL for E. coli). Select brands were frequently contaminated, with all samples of Brand 5 having elevated fluoride levels. Overall, one in four samples exceeded national standards for contaminants of public health concern. These findings reveal the poor quality of bottled drinking water in a suburb of Nairobi, presenting risks to consumers. There is a need to strengthen risk management and oversight of water packaging facilities in this setting.

Considering differences between sewered and onsite sanitation facilities, tools for holistic sanitation diagnostics are required to plan management solutions for city-wide inclusive sanitation. This study presents an integrated assessment of fecal sludge management with combined use of excreta flow diagrams and quantitative and qualitative analysis to evaluate fecal sludge volumes and composition accumulated in the onsite sanitation. The excreta flow diagram revealed that only 9% of the wastewater gets treated whereas 25% of the fecal sludge is buried underground while the remaining 66% are dumped directly into the environment openly without any treatment due to no designated disposal site. The study also highlights the variability in fecal sludge characteristics, with pit latrine sludge exhibiting 10–100 times higher concentrations of total solids, volatile solids, and chemical oxygen demand compared to septic tank sludge. The findings reveal that the indicators correlating fecal sludge characteristics are containment type, income level, and emptying. The presence of helminth eggs, particularly Ascaris Fertile Lumbricoids, within the sludge poses a risk to human health. In conclusion, this study highlights the immediate need for improved planning and implementation of fecal sludge management in low-middle income countries like Pakistan. The study's recommendations for treatment solutions aim to address the concentration and pathogen risks associated with fecal sludge, ultimately contributing to improved sanitation and public health outcomes.

There is limited understanding of the potential for anaerobic digestion and biogas production from fecal sludge. In this study, biomethane potential (BMP) tests from fresh, stored, and dewatered fecal sludge, together with co-digestion with fresh foodwaste, revealed that fresh fecal sludge produced similar cumulative biogas (CBG) to fresh foodwaste (615–627 mL/gVS), while stored fecal sludge showed a wide range of gas production (13–449 mL/gVS). Co-digestion significantly enhanced the CBG production of fresh (1.2×), dewatered (1.5×), and stored (29–36×) fecal sludge. In BMP tests with the higher range of gas production, a biphasic CBG production was observed, with degradation of readily biodegradable organics occurring during the first week. The first-order rate coefficients indicated hydrolysis limitation, which was also confirmed by the presence of slow-growing methanogens (Halobacterota). Priming with co-digestion significantly enhanced CBG from stored fecal sludge. The physical–chemical metrics VS/TS and TOC/TN were not predictors of biogas production, while BOD/COD and sCOD were better indicators, suggesting that metrics of stabilization representing biologically available fractions are more representative than metrics of entire pools of organic matter. This study suggests that biogas production from anaerobic digestion is viable for fresh fecal sludge, whereas for stored fecal sludge it requires co-treatment or pretreatment.

Carrying heavy loads increases the risk of pelvic organ disorders, particularly in low-income countries. Low self-efficacy hampers adoption of pelvic-floor-protective behaviors. The enabling hypothesis suggests that social support may strengthen women's behavioral self-efficacy. A three-arm parallel non-randomized controlled trial with 300 women and their social partners experimentally examined whether self-efficacy and social support can enable women’s pelvic-floor-protective behaviors in rural Nepal. Three villages received (1) self-efficacy (2) self-efficacy and social support promotion, or (3) information only control. The co-primary outcomes were reduced weight carried and using protective lifting techniques at 2-month follow-up. Self-efficacy promotion increased the use of protective lifting techniques 9% more than information only (d = 0.28). Weight was reduced by 3 kg more when additionally promoting social support compared to self-efficacy alone (d = 0.39). Self-efficacy and social support promotion enable women to better protect their pelvic floor health and may complement educational approaches to health behavior change in low-resource populations.

La gestion des déchets solides (GDS) est une question universelle qui touche chaque personne dans le monde : Partout, des défis considérables se posent pour faire face aux quantités croissantes de déchets produits quotidiennement, en raison de la croissance de la population et de l’urbanisation. Alors qu’une bonne gestion des déchets est essentielle pour protéger l’environnement et la santé humaine, 2 milliards de personnes n’ont toujours pas accès à un service de collecte des déchets solides, tandis que 3 milliards de personnes n’ont pas accès à des infrastructures de mise en décharge contrôlées. Il en résulte que d’énormes quantités de déchets sont jetées sur les trottoirs, déversées ou brûlées en plein air, contaminant l’eau, les nappes phréatiques et les océans de la planète. Ces pratiques provoquent des inondations en obstruant les systèmes de drainage, attirent nuisibles, rongeurs et autres vecteurs de maladies, augmentent les problèmes respiratoires, les émissions de gaz à effet de serre, et accentuent le changement climatique, tout en ayant un impact négatif sur la biodiversité et en augmentant l’épuisement des ressources.

Solid waste management (SWM) is a universal issue affecting every single person in the world: everywhere, tremendous challenges are faced to cope with the growing amounts of waste produced daily, as a result of population and urbanization growth. While sound waste management is key to protect the environment and human health, nowadays 2 billion people still lack access to solid waste collection service, while 3 billion people lack access to controlled disposal facilities. This results in tremendous amounts of waste being littered, dumped or openly burnt, contaminating water, groundwater and the world’s oceans. Such practices are causing floods by clogging drainage systems, attracting pests, rodents and other disease vectors, increasing respiratory problem, greenhouse gas emissions, enhancing climate change, while impacting negatively on biodiversity and increasing resources depletion.

Black soldier fly larvae (BSFL, Hermetia illucens (L.)) are recognized for efficient biowaste reduction while yielding valuable proteins and fats for animals. However, lignocellulosic fibers in biowastes are difficult to digest by biowaste and larval digestive tract microorganisms as well as the larvae themselves. This study investigated two biowaste physical pretreatments (thermal, mechanical) for improving BSFL processing of fibrous biowastes. Cow manure, spent grain, and grass clippings were thermally pretreated at 90 °C for three durations (0.5, 1 and 4 h). Contrary to expectations, thermal pretreatment resulted in either no improvement or decreased larval performance on all substrates, regardless of treatment duration. In contrast, mechanical pretreatment of spent grain and grass clippings, involving milling with three screen sizes (0.5, 1 and 2 mm) showed promising results. Specifically, bioconversion rates on 0.5 mm-milled spent grain and grass clippings increased by 0–53 % and 25–44 % dry mass, respectively compared to untreated. Additionally, larval protein conversion increased by 41 % and 23 % on spent grain and grass clippings, respectively. However, mechanical pretreatment did not affect fiber degradation by larval conversion, as hemicellulose decreased by 25 % and 75 % for spent grain and grass clippings, respectively, regardless of particle size. Particle size reduction influenced substrate microbial respiration (CO₂ mg/min), with 0.5-mm milled grass clippings exhibiting higher respiration compared to untreated, although this effect was not observed for spent grain. This study highlights mechanical pretreatment’s potential in enhancing BSFL bioconversion of fibrous biowastes and the importance of understanding substrate physical properties influencing substrate microorganisms and BSFL.

The banana tree circle (BTC) is a low-cost system for local greywater management, using a natural treatment and disposal process, providing additional resource recovery benefits. However, there are no standard design criteria for BTC that would allow for quality control of its efficiency and sustainability, and little is currently known about the full-scale performance of BTC. Based on the scoping literature review of 31 documents in the scientific database and eight documents from grey literature, a standard design model was proposed for the BTC technology based on the concept of water balance, greywater flows, rain, infiltration, and evapotranspiration. The first two steps of the BTC design were determining the areas required for infiltration and evapotranspiration. A cylindrical form trench, the soil percolation rate, and the hydraulic loading rate were considered for the infiltration area. The banana trees' evapotranspiration rate was taken into consideration for the evapotranspiration area. The proposed model was applied in a case study where we used a trench with 0.8 m depth and 1.5 m diameter. This study proposes a standard design criterion for the BTC based on environmental factors, and the scoping of the literature provides the basis for future studies to evaluate its environmental sustainability.

Urban sanitation is a basic service essential for public and environmental health. Incorporating various advances over the past two decades, the urban sanitation agenda has evolved towards the paradigm shift of Citywide Inclusive Sanitation (CWIS). Overall, CWIS aims at providing equitable and sustainable sanitation services and is closely linked to Sustainable Development Goal (SDGs) 6 on clean water and sanitation and directly and indirectly benefits several other SDGs. Since its inception in 2016, CWIS has evolved through various research and implementation experiences, resulting in four conceptual frameworks that redefine sanitation as a service delivery process, emphasizing the entire sanitation value chain and the coexistence of sewered and non-sewered technologies. This discussion paper draws on 77 journal articles and grey literature explicitly linked to CWIS, reviews the state of the art on the topic by comparing the four prominent CWIS frameworks and by identifying key advances, current gaps, and emerging issues to inform ways forward towards a more unified CWIS framework.

The SCENE Joint Initiative has established a Center of Excellence that covers a wide range of research areas related to net-zero emissions and provides a platform for cross-institutional collaboration in the ETH Domain. More than 100 researchers in 30 laboratories from all four research institutes of the ETH Domain (PSI, Empa, WSL, Eawag) and the two technical universities ETHZ and EPFL are involved. The project is led by PSI and runs from 01.01.2023 - 31.12.2025 with a total budget of approx. 17 million CHF. In this Annual Report, the activities and results of SCENE's first year of operation are presented. Further information about the project can be found at www.scene-project.ch.

Zusammen mit der Eawag und der OST erstellte Entsorgung & Recycling Zürich (ERZ) ein Wasserflussdiagramm (WFD) für das Stadtgebiet Zürich. Die weiterentwickelte Methode umfasst neu auch den Regen und die ausgelösten Durchflüsse, wie beispielsweise Mischwasserentlastungen, Versickerung und Evapotranspiration. Die leicht nachvollziehbare Darstellung des weiterentwickelten WFD eignet sich insbesondere, um bei der Planung von Schwammstadt- und Klimaanpassungsprojekte beigezogen zu werden. Sie steht auch für andere Anwendungen zur Verfügung.

Half of the world’s population is now served by non-sewered sanitation, yet the field remains fragmented, with a focus on individual research agendas, and prevalence of imprecise terminology that hinders scientific learnings and leads to misconceptions. The field is at a decisive juncture, with scientific knowledge taking off that holds the potential to fulfil the urgent need for inclusive sanitation in a rapidly urbanizing world. In this critical Review, relevant and diverse research results are assembled with findings translated to one consistent terminology, to provide scientific evidence to draw out interlinkages and learnings, debunk common misconceptions and identify key research needs. Properties of non-sewered wastewater are highly variable, and degradation during storage has a direct impact on greenhouse gas emissions and downstream treatment processes, which facilitate different resource recovery. New technologies and wastewater-based epidemiology can help to address the lack of monitoring. The findings are presented by wastewater properties, biological processes during storage, treatment processes and monitoring.

Objectives: Decisions about reproductive health are often influenced by women's female family members, particularly in low-resource contexts. However, previous research has focused primarily on individual behavioural determinants. We investigated the interrelatedness of female family members' reproductive health behaviour with a dyadic version of an extended health action process approach. We investigated this for carrying heavy loads during pregnancy and postpartum, a risk factor for reproductive health in many low-income countries such as Nepal.
Design: This cross-sectional study included dyads of daughters-in-law and mothers-in-law in rural Nepal (N=476, nested in 238 dyads).
Methods: Dyads of daughters- and mothers-in-law were surveyed about avoiding carrying heavy loads during pregnancy and postpartum. The effects of a woman's cognitions and her female dyadic partner's cognitions on their intention and behaviour about avoiding carrying loads were estimated using linear mixed models.
Results: The results showed that a mother-in-law's cognitions were related to her daughter-in-law's intentions and vice versa. The mother-in-law's cognitions were also related to the daughter-in-law's behaviour. The mother-in-law's self-efficacy and injunctive norms related to the daughter-in-law's intention and behaviour over and above the daughter-in-law's own self-efficacy and injunctive norms.
Conclusion: Female Nepali family members' cognitions about carrying heavy loads during pregnancy and postpartum are interrelated. Including female family members in interventions to help women manage their reproductive health in low-resource populations seems promising. These novel findings add to the growing body of research indicating the importance of including a dyadic perspective when understanding and changing health behaviour.

Plastic mismanagement and its subsequent pollution by rapid economic development and urbanisation pose significant challenges for modern world society. Notwithstanding one of the main sources for macro plastic leakage into the ocean from land, precise assessment of plastic pollution origins from Southeast Asia is yet to be clearly examined. In order to make informed decisions and prioritise areas of improvement it is required to better understand the waste leakage dynamics at the local level. In this work, the Waste Flow Diagram (WFD) was applied to understand the sources and fates of plastics leaking from the solid waste management system for the case of Tuy Hoa City, Phu Yen, Vietnam. The study shows scenarios of leakage into the aquatic environment ranging from 0.8 to 2.7 kg/cap/year, which originates mainly from the collection system. Targeted improvements to this stage of the service could reduce leakages and the overall environmental impacts of mismanaged plastic waste. The results of this study show the necessity and importance of having up to date and reliable data to better inform stakeholders and service planning, facilitating efficient action against plastic pollution. As the first peer-reviewed scientific article critically applying the WFD, this work highlights the steps and challenges of the methodology and critically analyses different methodological pathways.

Water, Sanitation, and Hygiene (WaSH) interventions are the most effective in reducing diarrheal disease severity and prevalence. However, very few studies have investigated the effectiveness of WaSH intervention in reducing pathogen presence and concentration. In this study, we employed a microfluidic PCR approach to quantify twenty bacterial pathogens in water (n = 360), hands (n = 180), and fomite (n = 540) samples collected in rural households of Nepal to assess the pathogen exposures and the effect of WaSH intervention on contamination and exposure rates. The pathogen load and the exposure pathways for each pathogen in intervention and control villages were compared to understand the effects of WaSH intervention. Pathogens were detected in higher frequency and concentration from fomites samples, toilet handle (21.42%; 5.4,0 95%CI: mean log₁₀ of 4.69, 5.96), utensils (23.5%; 5.47, 95%CI: mean log₁₀ of 4.77, 6.77), and water vessels (22.42%; 5.53, 95%CI: mean log₁₀ of 4.79, 6.60) as compared to cleaning water (14.36%; 5.05, 95%CI: mean log₁₀ of 4.36, 5.89), drinking water (14.26%; 4.37, 85%CI: mean log₁₀ of 4.37, 5.87), and hand rinse samples (16.92%; 5.49, 95%CI: mean log₁₀ of 4.77, 6.39). There was no clear evidence that WaSH intervention reduced overall pathogen contamination in any tested pathway. However, we observed a significant reduction (p < 0.05) in the prevalence, but not concentration, of some target pathogens, including Enterococcus spp. in the intervention village compared to the control village for water and hands rinse samples. Conversely, no significant reduction in target pathogen concentration was observed for water and hand rinse samples. In swab samples, there was a reduction mostly in pathogen concentration rather than pathogen prevalence, highlighting that a reduction in pathogen prevalence was not always accompanied by a reduction in pathogen concentration. This study provides an understanding of WaSH intervention on microbe concentrations. Such data could help with better planning of intervention activities in the future.

Inadequate solid waste management (SWM) can cause environmental contamination and health risks. Minimizing the health risks from SWM practices requires the identification of linkages between potential sources of exposure, environmental transport pathways, and adverse health outcomes. A safety planning approach can represent an innovative tool for reducing such risks. In previous research, we introduced the solid waste safety plan (SWSP) concept, only focusing on the health risk ranking assessment matrix. Here, we demonstrate the application of the SWSP framework in a case study of the municipal landfill of Novi Sad, Serbia. We identify potential hazards and assessed the likelihood and severity for them, using a combination of quantitative and semi-quantitative approaches to estimate risk levels for each identified hazard. Hazards deemed high and very high risks for the community and workers include groundwater contamination from leachate, airborne contaminants from combustion and non-combustion processes, and worker injuries associated with waste combustion. Control measures for each are identified, together with a corresponding cost analysis. Adding a final top cover to the landfill and introducing a collection, transport, and treatment system for the biogas would address hazards presenting high health risks but are also among the highest costs. While we demonstrate the approach and utility of an SWSP in a research context, future work is needed to assess the use of the SWSP by local communities or SWM utilities.

A collection of 32 open source Sanitation resources for practitioners in an exciting story of Jane's coincidences in a conference. For online use with clickable links to download the resources.

In this opinion article, we propose that self-supply, as a model for household-managed water supply in rural areas, is the foundational model for water supply in rural households. Any other model is only complementary while it lasts. Therefore, self-supply needs more emphasis in research and intentional exposure and support in practice. This is underscored by the fact that despite the use of taxes, transfers, and tariffs that fund other service models, major water service gaps still exist in rural households forcing them to invest directly in self-supply. Over 2.2 billion people globally still lack access to safe water. Our argument is not that other models such as communal or government models are irrelevant; rather, it is that self-supply is the foundational and often preferred model for rural households due to reliability, predictability, control, and flexibility. Yet it is overlooked often. Therefore, we call for investing in research informing self-supply policy, practice, and funding especially where it links with other models to be prioritized. This will likely accelerate the achievement of SDG 6.

Infrastructure investments, a core element of slum upgrading, play a role in improving the livelihoods of over 1 billion slum residents globally. Established planning practices often successfully deliver functional infrastructure but evidence shows that their contribution to improved livelihoods often either is absent or declines sharply after some time. To explain this limited effectiveness, this article identifies the missing link between infrastructure delivery and livelihood improvements as lying in the appropriation process, that is, the uptake and embedding of infrastructures into the daily practices of residents. Recent insights from sociotechnical transitions studies help to conceptualise appropriation. The authors use Munyaka informal settlement in Eldoret town, Kenya as a case to investigate the mechanisms of new infrastructure uptake. Findings indicate that appropriation is a social process that proceeds in three steps: reception, domestication and institutionalisation. This process is driven by the need to maintain or adjust residents' livelihood practices relative to prevailing socioeconomic and spatiotemporal conditions. The study concludes that appropriation is a significant process that planners should try to anticipate. Prevalent approaches to participation have to be modified accordingly. This is essential for planning to improve livelihoods in slums.

Despite decades of effort, progress in safely managed sanitation─a public sector mandate─is stalling due to limited public funding and poor governance, among other reasons. As a result, public health has suffered and environmental degradation has continued. Social enterprises that use innovative business models to provide on-site sanitation services, also known as sanitation enterprises, are considered an emerging solution. However, sanitation enterprises have not yet successfully replaced public provision at scale. This work explores the barriers that sanitation enterprises encounter in lower- and middle-income countries. Q-Method, a mixed-methods approach that assesses social perspectives on an issue, is used to evaluate major barriers and groups of dominant perception for 19 sanitation enterprises operating across 20 countries. A total of 25 mutually exclusive, collectively exhaustive barriers are identified, ranging from affording capital expenses to navigating political corruption. The results show that most of the identified barriers fall into the financial barrier category, with reaching economies of scale being the greatest obstacle for sanitation enterprises. On the basis of these results, the premise of independent profitability underlying the sanitation enterprise value proposition should be reevaluated. Four enterprise types are proposed and can explain half of the variance among the sanitation enterprises studied. The context of a sanitation enterprise, including its countries of operation, size, customer base, sources of revenue, and section of the sanitation value chain, influences the barriers that the enterprise encounters. This research underscores the crucial role of context in influencing barriers for sanitation enterprises, emphasizing the need for investment and for policy makers to take these contextual dimensions into account.

जेन के अनुभवों की एक रोमांचक कहानी के रूप में 32 ओपन सोर्स स्वच्छता संसाधनों का संग्रह, स्वच्छता प्रैक्टिशनर्स के लिए।. ऑनलाइन उपयोग के लिए, संसाधनों को डाउनलोड करने के लिए क्लिकेबल लिंक्स के साथ।

San Francisco is spearheading the city-wide installation of onsite non-potable water reuse systems (ONWS). Through a city ordinance, local authorities have induced a quickly growing ONWS market and initiated stakeholder networks that support the diffusion of ONWS solutions in San Francisco and beyond. [...]

Reasonable estimates for quantities and qualities (Q&Q) of fecal sludge that accumulate in onsite sanitation containments are fundamental for the design of appropriate management and treatment solutions, from community to city-scale. There are increasing attempts to improve Q&Q estimates, but current approaches are still at a conceptual level, and are not yet standardized with confirmed statistical relationships. To reach this level, we will need consistent approaches for planning, measuring, and global collaborations. Hence, the objectives of this study were: (1) to assess and compare Q&Q of fecal sludge from seven cities and communities, and explore statistical relationships that could be used to increase accuracy of Q&Q estimations; (2) to test and launch the Volaser device for measuring in situ volumes of fecal sludge; and (3) to capture lessons learned from field implementation with collaborators in seven countries during a global pandemic when no international travel was possible. The study took place in Ghana, India, Lebanon, Kenya, Sierra Leone, Uganda, and Zambia during the COVID-19 pandemic. Q&Qs were measured in 204 containments with a Volaser, laboratory analysis, and questionnaire. Results indicate that there are differences in Total Solids (TS) and Chemical Oxygen Demand (COD) in fecal sludge based on containment type, toilet type, source, and whether there is a water connection on the premises. Based on the results of this study, together with previously published open-source data, an empirical relationship for Volatile Solids (VS) and TS of 0.49 (R² = 0.88) was established using 1,206 data points. For COD/TS, no significant relationship was observed. Developing such empirical relationships will be useful for planning and modeling approaches. An external evaluation was conducted to evaluate overall project management, Volaser technology transfer, and effects of collaborating during the COVID-19 pandemic. Success factors for collaborating with new and existing partners without face-to-face meetings included laboratory capacity and experience with analytical methods, study objectives that were relevant for the partner and locality, and a strong quality assurance plan to ensure comparability of results. The lessons learned can be taken forward as ways to reduce carbon footprint, and contribute to resilient, inclusive development research projects.

Die voranschreitende Urbanisierung, die wachsende Bevölkerung und der Klimawandel erhöhen den Druck auf die Wasserressourcen, insbesondere in städtischen Gebieten. Das Wasserflussdiagramm (WFD) bildet den gesamten urbanen Wasserhaushalt in einer einfach verständlichen Grafik ab, weist auf Probleme und Chancen hin und eignet sich deshalb als Kommunikationsmittel und Diskussionsgrundlage für eine breite Zielgruppe. Damit ermöglicht das WFD, auf ein nachhaltiges und widerstandsfähiges Wassermanagement hinzuwirken.

Selection of appropriate sustainable treatment technologies involves satisfying user requirements, quality standards on treatment and products, and specific socio-technical constraints in the intended context. Using locally adapted multi-criteria assessment (MCA), this study investigated faecal sludge treatment technologies that enable resource recovery in Phnom Penh. A four-step structured approach was applied, involving i) identification of available options, ii) prerequisite screening, iii) MCA and iv) stakeholder discussions and ranking. Data were collected in a literature review, stakeholder interviews and an online survey. Lists of suitable primary (n = 7) and secondary (n = 13) treatment technologies were compiled based on the literature. Four secondary treatment technologies (solar drying, co-composting, vermicomposting, black soldier fly larvae (BSFL) composting) were retained after prerequisite screening and subjected to MCA. Co-composting was ranked highest in MCA, since it performed well in multiple aspects, especially for health criteria. However, when economic return on investment was prioritised and a lower treatment class was accepted, e.g. USEPA Class B biosolids, the highest ranking was achieved by vermicomposting or BSFL composting. If institutional criteria were included in the assessment, solar drying would likely be the highest-ranked option, since this simple technology requires less logistically complex stakeholder arrangements than co-composting. These results show that the ranking obtained for different sludge treatment options depends on criteria weighting and trade-offs. Considering secondary treatment options is crucial during early planning for faecal sludge management in a city of low-and-middle income countries, as the primary treatment must yield appropriate feedstock quality for the secondary treatment step.

Black soldier fly larvae (BSFL) waste processing has proven to be a promising approach, which can be applied in centralised or decentralised settings. Financial considerations however still remain undisclosed given business secrecy. Building on the experiences of a facility and operational setup in Indonesia, this study conducted an indepth cost analysis using methods such as time motion studies, activity based costing and a mass flow balance to evaluate business models. Thereafter followed an analysis of different scenarios on how to integrate the approach into the solid waste management system of Surabaya, Indonesia assuming different degrees of decentralisation with market rates and prices from 2020. Results show that a centralised plant, managing all steps of the BSFL process (Scenario 1), achieves the highest net present value (NPV), mainly through the economy of scale. When BSFL waste treatment is conducted using a decentralised approach, close to the waste sources, and the nursery and postprocessing of larvae remains at a central location (Scenario 3), other benefits besides the still positive NPV can be shown. Such a scenario for instance would reduce the spatial footprint of the central facility, create jobs within the communities and reduce the transport costs and total costs for the municipality. Another scenario (Scenario 2) hypothesises a decentralised waste treatment as well as post-processing of larvae at the same decentralised location increasing storability and the value of products. Although this achieves higher NPV values compared to Scenario 3, it requires larger scale units to achieve financial viability. Coordination and facilitation by local government can further strengthen a network of decentralised BSFL treatment plants, as the city authorities could focus on operating a centralised nursery (Scenario 2), supplying young larvae at low cost or free of charge to increase the financial viability of the decentralised plants treating the waste.

Multilateral development banks (MDBs) play a pivotal role in financing water and sanitation infrastructure projects and thus have a major impact on the development of basic services. Although information about the MDBs' investments is publicly available, it is dispersed and not easily comparable. A comprehensive compilation of MDBs' water and sanitation investments has long been lacking. To address this gap, we assess water and sanitation financing by the three MDBs most relevant to Africa and Asia between 1960 and 2020: the World Bank, the African Development Bank, and the Asian Development Bank. We compile a new dataset by drawing on 3,639 water and sanitation projects and assess territorial trends, technology choices, distribution of financial burdens, and reforms to institutional arrangements. We find that MDBs' investments align with changing patterns of urbanization and increasingly finance sanitation infrastructures including non-sewered technologies. However, our results also suggest that institutional reforms have addressed utility efficiency through investment in equipment and skills rather than through increased commercialization and private sector participation. The leverage effect of MDB investment on private financing is negligible, whereas co-financing from local governments dominates.

Citywide inclusive sanitation (CWIS) is becoming the dominant paradigm for achieving safe sanitation for all by 2030. Its technical benefits have been explored, but the bargaining over financial and organizational changes CWIS entails have not yet been adequately addressed. Our case study explains the stalled rollout of CWIS in Dhaka, Bangladesh. We analyse policy pathways over the past 30 years through a combined territorial political economy and power perspective to understand their effects on equality. We highlight how donors link the introduction of CWIS to the organization of sanitation through a market; how the utility uses CWIS as an opportunity to avoid costly responsibilities in non-sewered sanitation; and how service co-production through community-based solutions is neglected. CWIS has successfully overcome the dogmatic technological focus in the sanitation system, but for citywide sanitation to be scaled inclusively, the dogmatic focus in the organization and financing of the sanitation sector must also be overcome.

Replacing soybeans with insects in egg and poultry meat production could improve environmental sustainability. Black soldier fly larvae (BSFL) have a favorable nutrient composition and can be reared on low-grade waste, but this is associated with the risk of feed and food contamination. The aim of this study was to assess the transfer of selected contaminants from larval substrates to poultry-derived food. Two different control substrates were used. Substrate C_CH (produced in Switzerland) was based on side streams approved for insect rearing in the European Union (EU), while substrate C_IND (produced in Indonesia) included non-EU approved waste. In addition, substrate C_IND was spiked with either heavy metals (HM; 1.9 mg cadmium and 18.8 mg lead/kg dry matter (DM)) or 1.5 mg aflatoxin B1/kg DM (AF)). The larvae fed HM contained 7 mg cadmium and 16 mg lead/kg DM. These values were about 30 times the concentrations of cadmium and 30–60 times the concentrations of lead found on average in the BSFL reared with the two non-spiked substrates. Although substrate AF contained 842 μg aflatoxin B1/kg DM as analysed, the AF larvae contained only 4 μg aflatoxin B1/kg DM. Larval meals were integrated at 200 g/kg in two control diets (diets C_CH and C_IND) and two diets based on contaminated BSFL (diets HM and AF) designed for late-laying hens (n = 9/treatment). After feeding these diets for 4 weeks, the hens were slaughtered. Diet HM and AF did not affect laying performance or egg quality compared with the control diets. In the body tissue, the cadmium concentrations (per kg DM) were nearly doubled by diet HM in the breast meat (13.3 μg), kidneys (12.3 mg) and liver (1.86 mg) compared to diet C_IND. The same diet increased lead in kidneys from below 0.1 to 0.5 mg/kg DM. No lead was detected in the meat and eggs, and no cadmium was found in the eggs. In conclusion, despite cadmium and lead also occurring in BSFL meals of C_CH and C_IND, the levels in all corresponding hen-based feed and food materials were below the maximum content, except for the kidneys. The aflatoxin B1 level of diet AF (1 μg/kg DM) suggests that the risk might also be small when BSFL are reared on moldy substrate containing aflatoxin-producing fungi. In conclusion, postconsumer waste apparently poses a lower risk than expected in poultry food chains for these contaminants when used as larval substrate.

Mitigation of undesired byproducts from ozonation of dissolved organic matter (DOM) such as aldehydes and ketones is currently hampered by limited knowledge of their precursors and formation pathways. Here, the stable oxygen isotope composition of H₂O₂ formed simultaneously with these byproducts was studied to determine if it can reveal this missing information. A newly developed procedure, which quantitatively transforms H₂O₂ to O₂ for subsequent ¹⁸O/¹⁶O ratio analysis, was used to determine the δ¹⁸O of H₂O₂ generated from ozonated model compounds (olefins and phenol, pH 3-8). A constant enrichment of ¹⁸O in H₂O₂ with a δ¹⁸O value of ∼59‰ implies that ¹⁶O-¹⁶O bonds are cleaved preferentially in the intermediate Criegee ozonide, which is commonly formed from olefins. H₂O₂ from the ozonation of acrylic acid and phenol at pH 7 resulted in lower ¹⁸O enrichment (δ¹⁸O = 47-49‰). For acrylic acid, enhancement of one of the two pathways followed by a carbonyl-H₂O₂ equilibrium was responsible for the smaller δ¹⁸O of H₂O₂. During phenol ozonation at pH 7, various competing reactions leading to H₂O₂ via an intermediate ozone adduct are hypothesized to cause lower δ¹⁸O in H₂O₂. These insights provide a first step toward supporting pH-dependent H₂O₂ precursor elucidation in DOM.

Black soldier fly larvae composting is an emerging treatment option with potential to improve biowaste valorization in cities of low-income countries. This study surveyed the current generation and management status of food industry biowaste and their availability and suitability as potential feedstock for black soldier fly larvae (BSFL) composting treatment in three Tanzania cities, Dar es Salaam, Mwanza, and Dodoma. Biowaste-generating food industry companies (n = 29) in the three cities were found to produce banana peels, mango seeds, sunflower press cake, brewery waste, and coffee husks in large quantities (~100,000–1,000,000 kg y⁻¹). Around 50 % of these companies (16/29), primarily vegetable oil companies (10/11), either sold or gave away their waste as animal feed, while most companies (9/11) with unutilized food industry waste landfilled the generated biowaste. Multi-criteria analysis based on substrate availability criteria identified banana peels, mango seeds, and coffee husks with total score points of ≥10/12 as the most suitable feedstock for BSFL composting. However, multi-criteria analysis based on physical-chemical criteria identified brewery waste and sunflower press cake with total score points of ≥11/15 as the most suitable feedstock. Combined availability and physical-chemical properties of individual biowastes showed that all identified types of food industry biowaste can be suitable feedstock for producing BSFL biomass for protein production, but certain waste streams needed to be mixed with other waste streams prior to BSFL-composting to ensure sufficient availability and provide a balanced nutritional profile compared with the single-source biowastes. This study concluded that large volumes of food industry waste are being generated from food industry companies in Tanzania and there is need to establish new biowaste management interventions for resource recovery. Furthermore, for interested stakeholders in the waste management business, multi-stream BSFL-composting can be a suitable solution for managing and closing nutrient loops of the unutilized food industry biowaste in Tanzania and in other similar settings globally.

This study assessed the effects of environmental and operational hazardous events on the Bushenyi water supply system over the period 2017–2020. Monthly secondary water quality data for the period July 2013–December 2017 were analyzed together with data from field samples collected monthly from January 2018 to November 2020. The parameters analyzed were pH, tur-bidity, total iron, free chlorine and faecal coliforms. Hazardous events and risks affecting the water supply at the source, treatment and distribution system were identified and assessed during the field visits. Control measures were determined during water safety plan development effective July 2017 and implemented effective August 2018. Quality of water in the distribution system met the national standards for turbidity (93%), total iron (99%), residual free chlorine (90%) and faecal coliforms (96%). pH in the storage and distribution system was below the national standard (annual mean range, 5.5–6.7). Water quality was negatively influenced by extreme seasonal weather variations at the source, source protection gaps, treatment deficiencies related to clarifier, filter and chemical dose management as well as distribution management and maintenance gaps. Improved source protection, treatment and distribution network management and maintenance are recommended for sustainable system and water quality standards.

The availability and continuous supply of black soldier fly larvae (BSFL) is crucial for efficient operation of a BSF biowaste recycling facility. Its rearing performance was for the first time investigated in Pakistan under outdoor ambient weather conditions. Comparison of the findings with the BSF rearing performance of Indonesia’s facility highlights the life stages needing special attention. In Pakistan, mean BSF emergence, hatching and survival rate of 58.8% (SD 15.2), 44.5% (SD 21.8) and 91.4% (SD 1.68) were achieved respectively. A positive significant correlation was found between the number of emerged flies and prepupae (R = 0.75) and the number of eggs produced and hatched (R = 0.92). On average, BSF took 49.5 days (SD 3.20) to complete one life cycle (LC) under ambient temperature and relative humidity (RH) between (22-35 °C) and (24.7-89.3%) respectively. The mean duration of eclosion, pre-oviposition, egg hatching, larval feeding and pupation was 15.6 days (SD 1.6), 3.5 days (SD 0.5), 3 days (SD 0.6), 22 days (SD 2.5), 3.8 days (SD 1.2) respectively. In Pakistan, the LC duration was longer with a smaller number of eggs/fly, lower BSF emergence and hatching rates as compared to Indonesia. BSF tolerated the semiarid weather conditions of Pakistan, successfully developed into all instars and completed all LCs under observation. It is suggested to provide controlled environmental conditions at the nursery stage to improve BSFL rearing performance for sustainable biowaste management.

Introduction: Consistent and effective practice of water treatment, sanitation, and hygiene (WASH) behaviour is an indispensable requisite for realizing health improvements among children living in low-income areas with challenging hygienic conditions. Sustainably achieving such a behaviour change is challenging but more likely to be realized during epidemics, when health threats are high and the dissemination of information on preventative measures is intense. Our study conducted cross-sectional surveys in Surkhet District Nepal, before and during the Covid-19 pandemic to assess the impact of water safety interventions and hygiene training implemented before and during the pandemic on WASH conditions and practices and to assess the association of these changes with child health.
Methods: Information on WASH infrastructure, WASH behaviour, nutrition, and child health, including on parasitic infections, was obtained before and during the Covid-19 pandemic in spring 2018 and spring 2021, from 589 children aged between 6 months and 10 years and their caregivers. Data was collected through quantitative, structured face-to-face interviews, observations, health examinations of children including anthropometric measurements, analysis of children's stool, and water quality analysis. The association of changes in WASH factors with changes in child health was analysed using multivariate generalized estimating equations for repeated measures.
Results: Water safety management was significantly improved by the introduction of chlorination to piped water supply systems, which served 40% of households. In addition, the percentage of households using a ceramic water filter increased from 12.2% to 34.8%. Large and significant changes were observed in handwashing behaviour (frequency, use of soap and washing at critical times) and infrastructure: 35% of households constructed a new handwashing station. Kitchen and household hygiene also improved. An additional 22% of households improved the cleanliness of the toilet. The number of houses with a cemented floor increased by 20%.
WASH changes were significantly associated with improved child health: the chlorination of piped water supply reduced odds ratios for diarrhoea (OR = 0.36, 95% CI = 0.15–0.88, p = 0.025), respiratory difficulties (OR = 0.39, 95% CI = 0.16-0.92, p = 0.033), fever (OR = 0.42, 95% CI = 0.26-0.71, p = 0.001) and cough (OR = 0.58, 95% CI = 0.36-0.93, p = 0.024), and. The frequency of handwashing with soap was associated with significantly reduced odds ratios for infections with Giardia lamblia (OR = 0.68, 95% CI = 0.50-0.91, p = 0.011), stunting and wasting (OR = 0.75, 95% CI = 0.66–0.92, p = 0.003) and fever (OR = 0.85, 95% CI = 0.75–0.96, p = 0.008),. The presence of a handwashing station at baseline was associated with significantly reduced odds ratios for respiratory difficulties (OR = 0.45, 95% CI = 0.26-0.78, p = 0.004). The construction of a handwashing station between baseline and endline was significantly associated with reduced odds ratios for pale conjunctiva (OR = 0.32, 95% CI = 0.17–0.60, p < 0.001), which is a clinical sign of iron deficiency and anaemia, respiratory difficulties (OR = 0.39, 95% CI = 0.17-0.89, p = 0.026) and cough (OR = 0.44, 95% CI = 0.26-0.76, p = 0.003).
Using a clean container for the transport of drinking water was significantly associated with reduced odds ratios for infections with Giardia lamblia (OR = 0.39, 95% CI = 0.16-0.93, p = 0.033) and diarrhoea (OR = 0.48, 95% CI = 0.24-0.96, p = 0.038). Similarly, a cemented floor in the household was significantly associated with reduced odd ratios for diarrhoea (OR = 0.38, 95% CI = 0.16-0.87, p = 0.022) and infections with Giardia lamblia (OR = 0.44, 95% CI = 0.19-1.02, p = 0.056).
Conclusion: WASH training and the promotion of preventative measures during the Covid-19 pandemic supported improved water safety management and hygiene behaviour, which resulted in a reduction in infectious diseases among children in the study area.

Bengaluru represents a globally unique context for the diffusion of on-site wastewater treatment and reuse systems (ONWS). Local authorities have introduced a series of mandates that triggered a dynamically evolving mass-market for ONWS. [...]

Biowaste treatment with black soldier fly larvae (BSFL, Hermetia illucens L.) can promote a more sustainable food system by reusing nutrients that would otherwise be wasted. However, many agri-food wastes and byproducts are typically high in lignocellulosic fibers (i.e., cellulose, hemicellulose, and lignin), making it resistant to efficient larval and/or microbial degradation. Ammonia pretreatment could be used to partially degrade lignocellulose, making the biowaste more easily degradable by the larvae and/or microorganisms. This study evaluated ammonia pretreatment for lignocellulose degradation and its effect on BSFL performance on four fibrous biowastes: brewers spent grain, cow manure, oat pulp, and grass clippings. First, the optimal ammonia dose (1 % or 5 % dry mass) and pretreatment time (three or seven days) were assessed by measuring fibers after treatment and further examined using Fourier transform infrared spectroscopy (FTIR) spectra and scanning electron microscopy (SEM) images. Second, BSFL rearing performance on ammonia-pretreated substrates was assessed with a 9-day feeding experiment. Three-day pretreatment with 5 % ammonia was chosen as it decreased the total fiber content by 8–23 % for all substrates except cow manure. Contrary to expectations, ammonia pretreatment with all substates decreased BSFL rearing performance metrics by more than half compared to the untreated control. Follow-up experiments suggested that ammonia pretreatment had a dose-dependent toxicity to BSFL. Interestingly, three-day fermentation of cow manure and oat pulp increased bioconversion rate by 25–31 %. This study shows that ammonia pretreatment is not suitable before BSFL rearing. Ammonia toxicity to BSFL and other pretreatments, such as fermentation, should be further studied.

Product safety is a major concern when using edible insects and insect-derived products due to insects' diverse microbial community. Therefore, development of reliable post-processing treatments are required. Commonly used thermal treatments are effective against microorganisms but can have negative effects on product quality and nutritional value. Low-energy electron beam (LEEB) is an emerging non-thermal surface treatment technology for microbial decontamination of low water activity goods while preserving product quality. However, its potential application as an insect post-processing treatment has not been explored. To assess the effectiveness of LEEB treatment (250 keV and 12 kGy), three separate experiments were conducted with dried black soldier fly larvae (BSFL) and yellow mealworm (YMW). First, to assess LEEB's potential in inactivating microorganisms in insect products, LEEB treatment was conducted on dried BSFL inoculated with Escherichia coli K-12. Secondly, the effect of LEEB treatment on reducing naturally occurring microbial populations after microwave drying was evaluated. Finally, a six-month controlled shelf-life study (24 °C, 65% RH) was conducted to assess the long-term efficacy of LEEB treatment by monitoring physical, chemical and microbiological parameters. LEEB achieved a 4-log₁₀ reduction of inoculated E. coli K-12 on dried BSFL and was effective in reducing numbers of all microbiological parameters (aerobic and anaerobic counts) in YMW. Specifically, in non-inoculated samples, aerobic and anaerobic total viable counts (TVC) were reduced by approximately 4-log₁₀ colony forming units per gram (cfu/g) in YMW. In contrast, LEEB treatment moderately reduced microbial numbers in BSFL, with aerobic and anaerobic TVC reduced by approximately 1–2-log₁₀ cfu/g following LEEB treatment. Microbial counts in both BSFL and YMW remained lower than the control throughout the shelf-life. LEEB treatment did not have an influence on the peroxide value. Therefore, LEEB can be an effective and gentle processing technique to support safe dried insect products.

Reliable dewatering performance remains a key challenge in fecal sludge management, and the controlling factors or mechanisms are not well understood. There remain limited studies on constituents in feces and fecal sludge and how they affect the dewaterability of fecal sludge. This study aimed at evaluating a range of constituents in feces, and to gain empirical knowledge toward a mechanistic understanding of how they influence dewaterability. In this study, cellulose reduced capillary suction time, decreased supernatant turbidity, and increased cake solids. While hemicellulose decreased supernatant turbidity, lignin increased supernatant turbidity, capillary suction time, and cake solids. Extracellular polymeric substances (EPS) increased both capillary suction time and supernatant turbidity and decreased cake solids, whereas lipids increased turbidity. Cations had no significant effect on dewatering properties. Overall, fecal sludge stored in containments had better dewatering performance than ‘fresh’ fecal sludge, which was attributed to stabilization. Field fecal sludge had a higher relative abundance of Pseudomonas, which is associated with better aggregation, and fewer small particles (<10 μm) that clog filters to reduce dewatering performance. Further understanding of stabilization and developing an agreed-upon metrics of stabilization are essential for predicting fecal sludge dewatering performance, and developing smaller footprint dewatering treatment technologies.

The H+ area in Helsingborg, Sweden, is a sustainable city development project, served by "Tre-Rör-Ut" (Three-Pipes-Out), a world-unique source-separation and resource-recovery system for water, wastewater and food waste. [...]

The Jenfelder Au in Hamburg, Germany is a sustainable city development project, served by the "Hamburg Water Cycle" (HWC), a spearheading template for resource-recovery from source-separated water and wastewater, first of its kind at neighbourhood scale. [...]

Climate change, rapid urbanization and other grand challenges increasingly show that urban water and wastewater man-agement needs to be deeply rethought. A transformative shift is needed away from linear end-of-pipe to more circular system designs. Actors around the world have thus started developing decentralised urban wastewater treatment and reuse systems (DUWTRS). DUWTRS improve the flexibility, resilience and circularity of water and sanitation infrastructure and can thus play a key role in developing more sustainable cities. Yet, despite their high potential in solving multiple urban development challenges at once, only a few cities worldwide have successfully implemented them at scale. We thus lack well-documented templates and best practices of successful DUWTRS implementation. The Lighthouse Project aimed at filling this gap by assessing promising examples from around the world. To generate practice-oriented lessons, we compared six projects at different scales (city-wide vs. neighbourhood), in different contexts (high-income vs. low-/middle-income) and using different technological set-ups. We selected four neighbourhood-scale and two city-scale projects, equally distributed across high- and middle-income contexts. Data was collected between November 2021 and August 2022 through an extensive literature review and more than 100 semi-structured expert interviews. An integrative assess-ment framework was developed and used to derive key success conditions for DUWTRS implementation.

Nirvana Country Township is a high-end residential colony in Haryana State, which reuses treated effluent from on-site wastewater treatment facilities for urban greening in several residential areas. [...]

Access to water, sanitation, and hygiene (WASH) has been a challenge to south Asia’s rapidly growing and climate change-sensitive region. Nepal, a water-abundant country, faces obstacles to fulfilling the highly prioritized WASH Sustainable Development Goal 6 (SDG 6). This review offers details about Nepal’s WASH status from 2000 to 2020 with regard to the challenges Nepal had in delivering reliable WASH services to the people, as well as opportunities for a sustainable way forward, and provides insights that can be applied to other developing countries. From analysis of national-level assessments, estimates point toward healthy progress in extending WASH access to the population. However, large inequalities persist at the subnational level between urban and rural residents, between poor and rich residents, and between genders. Many local constraints such as a lack of long-term infrastructural capacity to provide and maintain WASH services, financial issues, and institutional and policy incompatibilities are some of the key factors that technical considerations and private sector involvement could address. We also propose roles for Nepal’s central, provincial, and local governments for identification and adaptation to the undeniable risks of climate change. Furthermore, there is a need to capitalize on the potential opportunities for developing a much-needed robust and climate-resilient WASH sector in Nepal, safeguarding the rights of future generations to safe and clean water.

City-wide inclusive sanitation (CWIS) aims at providing safe sanitation services to the entire population in line with SDG 6.3. In urban Nepal, the situation is challenging as only 11% of dwellers have access to toilets connected to sewers and the rest of the population relies on onsite sanitation with often no safe containment and no regular emptying, collection, treatment and disposal or reuse of sludge. [...]

SaniChoice is an open source web tool that enables informed sanitation technology and system choices as inputs in strategic planning. It can be used both for capacity development (e.g. in trainings and workshops) and as a decision support tool. This Practitioners' Guide is for engineering and planning consultants who aim to apply SaniChoice as a decision support tool in a facilitated multi-stakeholder Structured Decision-Making (SDM) process that is part of such frameworks as City Sanitation Planning (CSP), Sanitation 21 or Community-Led Environmental Sanitation (CLUES). [...]

Progress toward Sustainable Development Goals for global access to safe sanitation is lagging significantly. In this Feature, we propose that misleading terminology leads to errors of categorization and hinders progress toward sanitation service provision in urban areas. Binary classifications such as "offsite/onsite" and "sewered/nonsewered" do not capture the need for "transport to treatment" or the complexity of urban sanitation and should be discarded. "Fecal sludge management" is used only in the development context of low- or middle-income countries, implying separate solutions for "poor" or "southern" contexts, which is unhelpful. Terminology alone does not solve problems, but rather than using outdated or "special" terminology, we argue that a robust terminology that is globally relevant across low-, middle-, and upper-income contexts is required to overcome increasingly unhelpful assumptions and stereotypes. The use of accurate, technically robust vocabulary and definitions can improve decisions about management and selection of treatment, promote a circular economy, provide a basis for evidence-based science and technology research, and lead to critical shifts and transformations to set policy goals around truly safely managed sanitation. In this Feature, the three current modes of sanitation are defined, examples of misconceptions based on existing terminology are presented, and a new terminology for collection and conveyance is proposed: (I) fully road transported, (II) source-separated mixed transport, (III) mixed transport, and (IV) fully pipe transported.

Disaster-induced displacement often causes people to live in temporary settlements that have limited infrastructure and access to water, sanitation, and hygiene (WaSH). Reducing the risk of diarrheal diseases in such situations requires knowing how housing influences the presence of pathogens in water and the interaction between human settlements and exposure to pathogens. A cross-sectional study was conducted in May 2017 in two communities hard-hit by the Nepal 2015 earthquake: one recovered with newly reconstructed houses, and one recovered with residents still living in sheet metal temporary shelters constructed after the earthquake. We collected 60 water (30 drinking water and 30 cleaning water), 30 hand rinse, and 90 environmental swab samples (30 toilet handles, 30 utensils, and 30 water vessels) from selected households in each location and quantified 22 bacterial pathogens using microfluidic quantitative polymerase chain reaction (mfqPCR). A total of 59 samples were randomly selected for amplicon-based sequencing of the 16S rRNA, and it identified bacterial community profiles between these two settlements and their association with target genes of pathogenic bacteria. Target genes like uidA of Escherichia coli and the mip gene of Legionella pnuemophila showed significantly high frequency in specific sample types in temporary settlements than in permanent settlements. A significantly high concentration was observed in temporary settlements for Enterococcus spp. and S. typhimurium, specifically in swab samples. There was a sharp distinction of microbial community profiles between water and hand rinse samples with environmental swab samples, with a large abundance of potentially pathogenic bacteria in swab samples in both settlements. This observation highlighted that fomite could be an important transmission route for pathogens in rural settings and designing key interventions to target different stages of transmission pathways is essential. Overall findings from this study suggest that the recovered settlement with higher quality housing may be less impacted by fecal contamination than recovering settlements and that interventions should be designed to disrupt multiple transmission pathways to reduce pathogen exposure.

This policy brief presents the main result and policy recommendations from the field level assessment of sanitation facilities in the flood risk communities of Madhesh Pradesh. The field-level data were collected from twelve local government units (eight municipalities and four rural municipalities) spread across the province's four districts. The study found several factors causing slippage in sustainable toilet use. Some households do not have toilets, while some households with toilets are still practicing open defecation (OD). The dysfunctionality of toilet is one of the most significant factors driving these households to practice open defecation. The impacts of floods have further exacerbated toilets' dysfunctionality, making them less usable for households. Furthermore, households with poor finances are already practicing OD to avoid recurring costs associated with desludging. However, to reduce this in the long run, effective public-private investments are required around building public toilets and creating a sustain-able sanitation market and services. Also required would be the establishment of proper financing mechanisms for households to access funds to build and maintain a toilet, so that it is affordable and accessible for all throughout the year.

Inadequate solid waste management (SWM) can lead to environmental contamination and human health risks. The health risks from poor SWM can vary based on specific practices and exposure pathways. Thus, it is necessary to adequately understand the local context. This information, however, is rarely available in low-resource settings, particularly in rural areas. A solid waste safety plan could be helpful in these settings for gathering necessary data to assess and minimize health risks. As a step in developing such a tool, a semi-quantitative health risk analysis of SWM practices in nine Ghanaian rural villages was undertaken. Data on SWM in each village were collected through qualitative field observations and semi-structured interviews with local stakeholders. SWM-related health risks were assessed using the collected data, similar case studies in the scientific literature and dialogue among an assembled team of experts. The analysis identified context-specific practices and exposure pathways that may present the most substantial health risks as well as targeted solutions for mitigation risks. A risk assessment matrix was developed to quantify SWM risks as low, medium, high, or very high based on the likelihood and severity of identified hazards. The highest SWM risks were identified from dumpsites and uncontrolled burying of solid waste. More specifically, a very high or high risk of infectious and vector-borne diseases from SWM in the villages was identified, both in the disposal of solid waste in dumpsites and uncontrolled burying of solid waste. Additionally, a very high or high risk of inhalation, ingestion or dermal contact with contaminants was found in the disposal of solid waste in dumpsites, open burning of waste and reuse of waste from dumpsites as compost. The results demonstrate the potential value of a solid waste safety plan and a parsimonious approach to collect key local data to inform its contents.

The consistent use of household water treatment and storage (HWTS) technologies is necessary for human health. However, most HWTS options are designed for typical household use as opposed to emergency contexts, where use is less consistent. To investigate ways to improve the consistency of HWTS use in emergencies, we conducted in-person surveys with 108 households in northern Kenya and comparatively analyzed factors that influenced the use of household filters during a protracted drought. Findings showed that about 50% of respondents used their filter consistently over the course of the study. The main limitation to usability was that none of the filters were well-suited for the indoor living environment of the survey respondents. The factors associated with consistency of use varied by filter design. For one-bucket filters, consistent use was associated with ease of assembly, reported availability of spare parts, and peer approval of HWTS use. For two-bucket filters, consistent use was best explained by the certainty regarding when the filter was functioning or not. We suggest that filter manufacturers should reduce the number of parts to mitigate assembly difficulties and should develop flexible filter designs to improve compatibility across households in terms of space and height requirements. Those disseminating filters during protracted emergencies should conduct user training on the assembly and disassembly of unfamiliar filters and ensure affordable access to necessary replacement parts. Finally, to improve consistency of use of new types of filters, implementers should assess the peer approval of these HTWS options among the target population.

Not all the challenges of informal settlement upgrading programmes can be anticipated from the start. It calls for cumulative learning within the programme's timeline. This paper investigates the role of organizational learning in influencing programme outcomes. The analysis of the Kenya Informal Settlement Improvement Programme (KISIP) shows that a lack of organizational learning routines can lead to reduced programme success, and that programme learning can improve programme outcomes. Well-conceptualized processes that include participation, coordination, communication and the synthesis of information are essential, though insufficient alone. Additional barriers, including a sudden increase in the number and diversity of actors and projects, their deteriorating commitment, inequitable incentives and inadequate tools to support programme learning, can further exacerbate the absence of established programme learning routines. There is a need for explicit and transparent programme learning procedures across organizational levels in order to improve overall programme success.

Poor and unpredictable dewatering performance of fecal sludge is a major barrier to sanitation provision in urban areas not served by sewers. Fecal sludge comprises everything that accumulates in onsite containments, and its characteristics are distinct from wastewater sludges and from feces. There is little fundamental understanding of what causes poor dewatering in fecal sludge. For the first time, we demonstrate that particle size distribution is a driver of dewatering performance in fecal sludge, and is associated with level of stabilization. Higher concentrations of small particles (<10 μm) and smaller median aggregate size (D50) corresponded to poor dewatering performance (measured by capillary suction time (CST) and supernatant turbidity) in field samples from Kenya and Uganda and in controlled laboratory anaerobic storage experiments. More stabilized fecal sludge (higher C/N, lower VSS/TSS) had better dewatering performance, corresponding to lower concentrations of small particles. Samples with the largest aggregates (D50 > 90 μm) had higher abundance of Gammaproteobacteria Pseudomonas, and samples with the smallest aggregates (D50 ≤ 50 μm) were characterized by higher abundance of Bacteroidetes Vadin HA17 and Rikenellaceae. Contrary to common perceptions, stabilization, particle size distribution, and dewatering performance were not dependent on time intervals between emptying of onsite containments or on time in controlled anaerobic storage experiments. Our results suggest that the stabilization process in onsite containments, and hence the dewaterability of sludge arriving at treatment facilities, is not dependent on time in containment but is more likely associated with specific microbial populations and the in-situ environmental conditions which promote or discourage their growth.

The presence of septic tank effluents in open spaces and roads due to poor fecal sludge management (FSM) in low-income cities represents a source of fecal contamination and potential risk of fecal-oral disease transmission. This study aimed at assessing fecal contamination exposure through six exposure pathways in Abobo, District of Abidjan in Côte d’Ivoire. The public health risk was evaluated in two clusters to identify the dominant exposure pathways and to compare which populations were most exposed. The SaniPath approach used included behavioral surveys (transect walk, household survey, school survey and community survey) and laboratory analysis. Surveys were conducted among 200 households, 6 schools and 4 community groups. In addition, 120 environmental samples were collected (in 2 clusters of 6 pathways with 10 samples per pathway per cluster). The colony forming unit (CFU) of E. coli was determined in samples using the surface plating technique on agar medium. Bayesian analyses were performed to estimate the distributions of fecal concentration and contact frequency, and exposure to fecal contamination was estimated using the Monte Carlo method with 1000 iterations. The highest concentrations of E. coli were observed in open drains (6.1 log CFU/ml), gullies (6 log CFU/ml) and soil (5.8 log CFU/ml) samples. The dominant exposure pathways were determined by multiplying the dose and the percentage of the population exposed, which was then log-transformed and denoted by (E). The study found that street food and gullies are the two dominant exposure pathways among the population living in Abobo. 100% of the children and between 73% and 91% of the adults are exposed to these dominant pathways in low and poor areas. In middle and high-income areas this concerns 75% to 95% of children and between 26% and 70% of adults. As well, the risk of exposure to the dominant pathways hits 9.2 in children and 8.6 for adults living in poor areas. While it reaches 8.1 and 7.1 respectively in children and adults living in middle and high-income areas. The study outcomes could help the authorities to structure how to target municipal wide interventions toward improving the sanitation conditions in the different neighborhoods.

The interplay between menstrual waste and urban sanitation infrastructure is largely hidden from view. Qualitative research has highlighted socio-cultural aspects of menstruation, but few quantitative studies have mapped the physical situation at scale. This study surveyed 258 women in Blantyre, Malawi about their menstrual absorbent choices, disposal practices, and socio-demographic characteristics. A Sankey diagram visualised flows of menstrual waste in the urban environment and identified ultimate disposal points. Most participants used either disposable pads and/or old cloth and disposed of them by either burning and/or throwing in pit latrines. Pad and cloth use were associated with age, education, employment, marital status, and household wealth. Younger women’s preference for disposable pads suggests that demographic shifts may cause volumes of menstrual waste to increase. However, differences in waste volume produced by disposable and reusable absorbents was less than previously assumed. The volume of menstrual waste discarded in pit latrines, and cultural barriers to disposing it elsewhere, highlights challenges for the pit emptying industry and faecal sludge value recovery sector, with the problem anticipated to be most acute in high-density settlements. Widening access to sustainable disposal strategies, affordable reusable menstrual products, and tackling stigma, are key to addressing this social and environmental challenge.

The purpose of this study was to identify the psychosocial factors of chlorinated water uptake and to design effective behavior change techniques applying the risk, attitude, norm, ability, and self-regulation (RANAS) behavior change model. This cross-sectional study was conducted in two Rohingya refugee camps in Cox’s Bazar, Bangladesh. In total, 596 respondents were recruited through systematic random sampling. A structured interviewer-administered questionnaire was used to assess the psychosocial factors according to the RANAS model. We used correlation analysis and multivariable linear regression models to predict the psychosocial factors of the consumption of chlorinated water. The respondents in this study had a medium to high habit of drinking chlorinated water. For the overall sample, participants’ habits were predicted by income, perceived vulnerability, like of chlorinated water, feelings of being healthy, action planning skills, and coping planning skills. In Camp 14, income, vulnerability, and coping planning were strongly influential in predicting habit; in Camp 16, liking chlorinated water and action planning were the most influential factors. Behavior change techniques against each factor with proper communication channels have been proposed for the overall sample and specific to each camp. The psychosocial factors identified and the behavior change strategies proposed in this study may help to promote chlorinated water consumption among the camp population. This study also recommends follow-up research that considers more contextual factors, uses larger sample sizes, and examines the effectiveness of the intervention.

Over 70 per cent of India’s surface water is polluted by human excreta and other waste and less than 35 per cent of urban wastewater is treated. This poses a severe risk to public and environmental health. Urban waterbody rejuvenation in India often focuses on aesthetic improvements rather than addressing its systemic interdependencies with sanitation. This paper establishes these systemic links through a mixed-methods study using water-quality testing and stakeholder interviews in the city of Bengaluru, India. A conceptual system dynamics model of technical, social, institutional and environmental factors is developed. Results show that sewage leaks into lakes via stormwater drains are a major pollution pathway, among others. Three system levers for positive change have been identified: coordination of government entities, adequate faecal sludge management and strong citizen involvement. Citywide inclusive sanitation (CWIS) is proposed as an approach to provide leverage and solve the intertwined issues of public and environmental health.

Background The COVID-19 pandemic drew hygiene to the center of disease prevention. The provision of adequate water, sanitation, and hygiene (WASH) services is crucial to protect public health during a pandemic. Yet, access to levels of water supply that support adequate hygiene measures are deficient in many areas in Nepal. We examined WASH practices and their impact on child health and nutritional status in two districts before and during the COVID-19 pandemic.
Methods A longitudinal and mixed method study was conducted in March-May 2018 and November–December 2021. In total, 715 children aged 0-10 years were surveyed at baseline. Of these, 490 children were assessed at endline. Data collection methods included observations, a questionnaire, stool analysis, anthropometric measurements, water quality analysis, and an assessment of clinical signs of nutritional deficiencies. We conducted 10 in-depth interviews to understand major problems related to COVID-19.
Results Most respondents (94.2%) had heard about COVID-19; however, they did not wear face masks or comply with any social distancing protocols. Almost 94.2% of the households self-reported handwashing with soap 5-10 times per day at endline, especially after defecation, compared to 19.6% at baseline. Water quality was better at endline than at baseline with median 12 to 29 CFU Escherichia coli/100 mL (interquartile range at baseline [IQR] = 4-101) at the point of collection and 34 to 51.5 CFU Escherichia coli/100 mL (IQR = 8–194) at the point of consumption. Fever (41.1-16.8%; p = 0.01), respiratory illness (14.3-4.3%; p = 0.002), diarrhea (19.6–9.5%; p = 0.01), and Giardia lamblia infections (34.2-6.5%, p = 0.01) decreased at endline. In contrast, nutritional deficiencies such as bitot’s spots (26.7-40.2%; p = 0.01), pale conjunctiva (47.0-63.3%; p = 0.01), and dermatitis (64.8-81.4%; p = 0.01) increased at endline. The inadequacy of the harvest and the lack of household income to meet households' nutritional needs increased drastically (35.0-94.2%; p = 0.01).
Conclusion We found that improved water quality and handwashing practices were associated with a decrease in infectious diseases. However, food security also decreased resulting in a high prevalence of nutritional deficiencies. Our findings underline that disaster preparedness should consider access to adequate WASH, nutrition, and health supplies.

This study sought to identify the psychosocial factors that influence handwashing behaviour and to design behaviour change techniques applying the risk, attitude, norm, ability, and self-regulation (RANAS) behaviour change approach in Rohingya camps in Cox's Bazar, Bangladesh. This was a cross-sectional study conducted in four Rohingya camps located in Ukhiya and Teknaf sub-districts. Participants were selected by systematic random sampling. A structured interviewer-administered questionnaire was used. Analysis of variance testing (ANOVA) was used to determine the significant predicting variables. A total of 1,358 individuals participated in the interview. The mean age was 31.11 ranging from 13 to 75 years. The majority were female (84.9%). Around 75% of participants reported practising handwashing. Several psychosocial predictors were identified for handwashing behaviour with medium to large effect size such as health knowledge, beliefs about costs and benefits, feelings, social norms, abilities, and self-regulation factors. Significant predictors were additionally identified in individual camps. The behaviour change techniques included providing information, demonstration of handwashing, providing rewards, evoking emotions, and public commitments amongst others proposed in this study. Identified psychosocial determinants should be considered while promoting sustainable handwashing behaviour along with adequate supplies and infrastructure. This study also suggests evaluating the proposed behaviour change interventions considering the contextual factors related to handwashing.

Health psychology research is inherently context specific: Different health behaviors are executed by different target groups (e.g., gender, age) in different social structures, cultures, and environments. This asks for the adaptation of research instruments to enhance specificity. For example, when using measurement scales in new contexts, translation and psychometric validation of the instruments are necessary but not sufficient if the validity of the psychological concept behind a measurement scale has not been researched. In this study, we build on existing guidelines of translation as well as psychometric validation and present four steps on how to adapt measurement scales to a new context: Step 1 asks whether the psychological concept is found in the new context. Step 2 asks whether the measurement scale and its items are understood in the new context. Step 3 asks whether a measurement scale is valid and reliable. Step 4 asks how the items of the measurement scale perform individually. Following these four steps, measurement scales are carefully translated, adapted, and validated and can therefore be transferred to very different contexts.

Sanitation is a fundamental determinant of human health and well-being, and is essential for protecting the environment and enabling economic and social development. Ensuring universal, equitable and sustainable access to safe sanitation in all settings is a political priority in the pan-European region. This publication aims to support implementation of the provisions on sanitation under the Protocol on Water and Health, as well as national and international goals and targets on sanitation by providing an overview of the situation of sanitation and wastewater management in the region, describing current and emerging issues in ensuring access to safe and sustainable sanitation services, and proposing key action areas to strengthen sanitation governance. It is primarily targeted at national decision-makers and supports public health and environment authorities, surveillance agencies, sanitation service providers and other relevant stakeholder.

The larvae of the black soldier fly (BSFL, Hermetia illucens) efficiently close resource cycles. Next to the nutrient-rich insect biomass used as animal feed, the residues from the process are promising plant fertilizers. Besides a high nutrient content, the residues contain a diverse microbial community and application to soil can potentially promote soil fertility and agricultural production through the introduction of beneficial microbes. This research assessed the application of the residues on plant-associated bacterial and fungal communities in the rhizosphere of a grass-clover mix in a 42-day greenhouse pot study. Potted soil was amended with BSFL residues (BR+) or conventional compost (CC+) produced by Rwandan waste management companies in parallel to residues and compost sterilized (BR-, CC-) by high-energy electron beam (HEEB) as abiotic controls. The fertilizers were applied at a rate of 150  kg N  ha⁻¹. Soil bacterial and fungal communities in both fertilizer and soil were assessed by high-throughput sequencing of ribosomal markers at different times after fertilizer application. Additionally, indicators for soil fertility such as basal respiration, plant yield and soil physicochemical properties were analyzed. Results showed that the application of BSFL residues influenced the soil microbial communities, and especially fungi, stronger than CC fertilizers. These effects on the microbial community structure could partly be attributed to a potential introduction of microbes to the soil by BSFL residues (e.g., members of genus Bacillus) since untreated and sterilized BSFL residues promoted different microbial communities. With respect to the abiotic effects, we emphasize a potential driving role of particular classes of organic matter like fiber and chitin. Indeed, especially taxa associated with decomposition of organic matter (e.g., members of the fungal genus Mortierella) were promoted by the application of BSFL residues. Soil fertility with respect to plant yield (+17% increase compared to unamended control) and basal respiration (+16% increase compared to unamended control) tended to be improved with the addition of BSFL residues. Findings underline the versatile opportunities for soil fertility arising from the application of BSFL residues in plant production and point to further research on quantification of the described effects.

Over 2 billion people globally lack access to safely managed drinking water. In contrast to the household-level, manually implemented treatment products that have been the dominant strategy for gaining low-cost access to safe drinking water, passive chlorination technologies have the potential to treat water and reduce reliance on individual behavior change. However, few studies exist that evaluate the performance and costs of these technologies over time, especially in small, rural systems. We conducted a nonrandomized evaluation of two passive chlorination technologies for system-level water treatment in six gravity-fed, piped water systems in small communities in the hilly region of western Nepal. We monitored water quality indicators upstream of the treatment, at shared taps, and at households, as well as user acceptability and maintenance costs, over 1 year. At baseline, over 80% of tap samples were contaminated with Escherichia coli. After 1 year of system-level chlorination, only 7% of those same taps had E. coli. However, 29% of household stored water was positive for E. coli. Per cubic meter of treated water, the cost of chlorine was 0.06-0.09 USD, similar to the cost of monitoring technology installations. Safe storage, service delivery models, and reliable supply chains are required, but passive chlorination technologies have the potential to radically improve how rural households gain access to safely managed water.

More than 1/3 of the global population relies on onsite sanitation systems, and in some cases entire urban areas in low- and middle-income countries are not served by sewers. Improved options for the management of fecal sludge that accumulates in these onsite systems are required immediately, as the majority of it is currently discharged untreated into the urban environment, placing a huge burden on public and environmental health. One of the greatest obstacles to establishing more reliable and accessible fecal sludge treatment is inconsistent and unpredictable solid-liquid separation. Extreme influent variability in influent fecal sludge poses operational problems with settling and dewatering, reducing the capacity of existing centralized and semi-centralized treatment facilities and hindering the transfer of low-footprint technologies which could extend decentralized and community-scale sanitation coverage in high-density urban areas. [...]

Globally, the sanitation needs of three billion people are met by non-sewered sanitation. Small-footprint treatment technologies are needed that are appropriate for dense urban areas. Blackwater (BW) (or fecal sludge), contains more than 95% liquid, and dewatering it without conditioning requires large footprints. Chemically-enhanced dewatering with conditioners is a promising option to increase dewatering performance and reduce required footprints. However, before implementation of this solution there is a need for increased knowledge on selection and dosing of conditioners. This study evaluated bio-based and synthetic conditioners (chitosan, tannin-, and starch-based, synthetic with and without poly-acrylamide) with 14 types of BW from five countries. The supernatant after settling with jar-tests was analyzed to quantify optimal dose and dewatering performance. The reduction of total chemical oxygen demand (COD) was >55%, achieved by removal of particulate constituents with mainly soluble COD remaining in the supernatant. A reduction in particulate COD could lead to increased efficiency of soluble COD in supernatant treatment. Bio-based conditioners are as effective as synthetic conditioners, and when performance was variable, it was due to differing properties of TSS, TS, EC and pH. Optimal conditioner dose for synthetic conditioners and chitosan could be predicted using concentrations of total solids (TS) (R² > 0.7), whereas optimal dose for starch- and tannin-based conditioners could be predicted with electrical conductivity (EC) (R² > 0.8), and colloid titration (R² > 0.8). In addition, real-time optical TSS and EC sensors could accurately predict chitosan dose for fresh BW treated at source (R² = 0.97, R² = 0.95). This study validates that use of conditioners for dewatering with highly variable BW can be implemented with real-time measurements for optimal dose, in globally relevant implementations.

Sanitation is fundamental to a city’s health, liveability, and social and economic development. Yet, as the world continues to urbanise, progress in urban sanitation is outpaced by rapid urbanisation and population growth. Today, about 40% of the world’s urban residents do not have safely managed sanitation, with a vast majority of them are living in low- and middle-income countries (LMICs). In the last five decades, numerous international development agendas on urban sanitation have been set and failed to reach the expected sanitation outcomes in LMICs. Reasons for this failure include poor planning, narrow infrastructure focussed approach, inadequate consideration of contextual factors, lack of attention to policy and institutions, and absence of community involvement. [...]

Die Abwasserentsorgung ist von grundlegender Bedeutung für die Gesundheit, die Lebensqualität sowie die soziale und wirtschaftliche Entwicklung einer Stadt. Doch während die Welt immer weiter verstädtert, werden die Fortschritte bei der städtischen Abwasserentsorgung durch die rasche Urbanisierung und das Bevölkerungswachstum überholt. Heute verfügen etwa 40 % der Stadtbewohner weltweit nicht über eine sichere Abwasserentsorgung, wobei die überwiegende Mehrheit von ihnen in Ländern mit niedrigem und mittlerem Einkommen (LMICs) lebt. In den letzten fünf Jahrzehnten wurden zahlreiche internationale Entwicklungspläne für die städtische Abwasserentsorgung aufgestellt, ohne dass die erwarteten Ergebnisse in den LMICs erreicht wurden. Zu den Gründen für dieses Scheitern gehören schlechte Planung, ein eng auf die Infrastruktur ausgerichteter Ansatz, eine unzureichende Berücksichtigung kontextbezogener Faktoren, mangelnde Aufmerksamkeit für Politik und Institutionen sowie eine fehlende Einbeziehung der Bevölkerung. [...]

As the importance of fecal sludge management (FSM) is increasingly being realized, the need for adequately designed and functioning fecal sludge (FS) treatment plants is also increasing. Research to fill this gap is only emerging and dewatering is a key challenge for developing sustainable treatment solutions. This study evaluated the effect of extracellular polymeric substances (EPS) on dewaterability of FS, and how EPS and dewaterability change during anaerobic storage (as a proxy for time in onsite containment). EPS was extracted from FS and activated sludge using Na₂CO₃ and sonication and added to sludge samples to determine the effect on dewaterability. The results confirmed that an increase in EPS had a direct impact of decreasing FS dewaterability (as capillary suction time). In this context, we evaluated FS degradation during anaerobic storage, the effect of anaerobic storage time on EPS, EPS fractions and particle size distribution, and the effect of variations in these factors on FS dewaterability. Variations in EPS, EPS fraction and particle size distribution during anaerobic storage were less than expected and average VS reduction of 20% was recorded over 7 weeks. Although anaerobic digestion was verified (biogas production), the results indicate that kinetics of degradation of FS is different from wastewater sludges. Comparatively, EPS fractions in FS were 70 – 75% lower and with higher fractions of humic-like substances than wastewater sludges. Although EPS significantly affects FS dewaterability, anaerobic storage time is not a predictor of dewaterability.

1. Due to the increasing global demand for more sustainably produced animal protein, there is an intensive search for feeds to replace soybeans. Black soldier fly larvae (BSFL) appear to have great potential for replacing soybeans in poultry diets. The main objective of this study was to determine if the nutritional value of BSFL is superior to soybeans when feeding organic broilers, since smaller amounts of BSFL could replace the soybean content in the feed, thus saving even more resources.
2. Eighty Hubbard S757, a slow growing organic broiler type, were fattened for 63 d, spending the last 49 d on one of five diets. Two soybean cake- and soybean oil-based diets (SS, SS-) were compared with three diets based on partially defatted BSFL meal and BSFL fat from two origins (AA-, AB-, BB-). Different from diet SS, diets SS-, AA-, AB-and BB- were designed with approximately 20% less lysine and methionine. Growth (n = 16), metabolisability, body nitrogen retention, carcase and meat quality (n = 8) were evaluated.
3. Broilers of the insect-based feeding groups, AA- and AB-, grew similarly well compared to those of group SS. They also retained more nitrogen in the body than those fed BB- and SS-. Breast meat yield was higher with AA- and AB- than with BB- and SS-, but still lower than with SS. Dietary variations in physicochemical meat quality were of low practical relevance. Diet BB- resulted in a more yellow skin and meat. The fatty acid profile of the breast meat lipids reflected the high lauric acid proportion of the BSFL lipids, resulting in up to 80 times higher proportions than when feeding the soybean-based diets.
4. The results indicate that high-quality BSFL, depending on their origin, may indeed be superior to soybean protein, but that the meat lipids from BSFL-fed broilers can contain significant amounts of lauric acid, which, from a human nutrition perspective, could have a negative impact on meat quality.

Sanitation is a universal need and thus requires universal access. Despite having the world’s largest sanitation campaign, only 37% of urban India has access to safely managed sanitation systems. Due to the heterogeneity of Indian cities, a mix of different sanitation systems is required to meet the demands of these rapidly urbanising cities. The Manila principles on Citywide Inclusive Sanitation (CWIS) propose a mix of technologies as a key pillar in achieving the Sustainable Development Goals on urban sanitation. However, there is a lack of understanding on the criteria to consider when planning the technological options for CWIS. The mega-city of Chennai is chosen as a case study, and mixed methods including a Faecal Waste Flow diagram (SFD), Social Network Analysis (SNA) and interviews are applied. This study then presents a set of 14 contextually relevant criteria for the implementation of sewered and non-sewered technologies in the city. The SFD shows that 35% of Chennai’s faecal waste remains unsafely managed while using SNA identified that the water and sanitation utility, the municipal corporation and the slum clearance board are the best placed stakeholders in the city to create a change in the sanitation situation. Furthermore, 17 drivers and barriers for the implementation of non-sewered technologies are identified. The criteria catalogue was also theoretically tested for an example ward in Chennai. The findings of the study show that a catalogue of physical, technical, institutional and financial criteria is useful for planning a mix of technologies with the CWIS approach.

More than a third of women in Nepal have to carry water from source to home to satisfy their families’ daily needs. A cross-sectional study was carried out in a hilly area in Nepal to assess water-carrying practices and their association with women’s health. Quantitative interviews were conducted with 1001 women of reproductive age and were complemented with health surveys carried out by health professionals and structured observations of water carrying. Multivariate mixed logistic regression models were used to assess the associations between water-carrying-related risk factors and health issues for women. Around 46% of women faced considerably increased to excessive physical stress due to water carrying during the dry season. Women suffered from a disproportionately high prevalence of back pain (61%), with about 18% of this pain being horrible to excruciating; pain in the knees (34%); uterine prolapse (11.3%); and at least one spontaneous abortion (9%). The risk category of water carrying was significantly associated with uterine prolapse (OR = 1.44, 95%CI = 1.12-1.85, p = 0.031) and pain in the hips (OR = 1.69, 95%CI = 1.27-2.26, p<0.001). Receiving help with water carrying during pregnancy and during the first three months after delivery was associated with reduced odds ratios for uterine prolapse (OR = 0.10, 95% CI = 0.01-0.87, p = 0.037), and strong back pain (OR = 0.32, 95% CI = 0.12-0.87, p = 0.026). Improvements to water supply infrastructure and the promotion of social support for carrying water during pregnancy and after delivery are recommended to reduce water-carrying-related health risks.

The academic literature largely acknowledges participation as a key condition for the successful upgrading of informal settlements. However, how individual participative actions of different actor groups and reactions of dwellers combine to influence project outcomes of upgrading processes has not been studied. This article posits that different combinations of presence or absence of collaborative interactions between dwellers and other actors will decisively predict the success and failure of projects. Specifically, we argue that interactions between different groups of implementers and dwellers are conditioned by distinctive value systems - institutional logics - , which provide specific challenges to establishing collaborative interactions with dwellers as the actors conduct their roles. We identify sufficient combinations of participative actions that may lead to successful upgrading using qualitative comparative analysis (QCA) on 15 informal settlements in Kenya's secondary towns that were recently upgraded. Our findings indicate that participation has to consider a multiplicity of actors, who are guided by different logics; it has to span over the whole implementation cycle. It also has to deal reflexively with the issue of representation of the community. This extends the understanding of participation to a perspective that emphasizes the capabilities of implementers to enact collaborative relationships by bridging between their own and the community's institutional logic.

Previous research suggests that community-based participation, a process through which beneficiaries can actively influence and define the direction and execution of development programs, can promote long-term uptake, use, and management of shared resources, such as community-based safe water infrastructure. However, results are heterogeneous. Psychological ownership theory and initial evidence suggests that participation promotes positive outcomes for shared resources by fostering sense of ownership through three routes: having control, intimate knowledge, and investing the self. This study used community-based safe water infrastructure as an example to investigate how various forms of participation affect acceptance, use, and functionality of a shared resource and whether this effect is mediated by psychological ownership. We conducted a nonrandomized cluster-based controlled trial with pre–post intervention assessment (N = 369) in 33 villages in rural Nepal, where safe water infrastructure is shared. Participatory intervention activities (e.g., influence in decision-making, contributing materials and labour) favourably affected self-reported outcomes and use of the water supply infrastructure but not observed functionality or drinking water quality. In conclusion, this study supports the assumption that participation can foster psychological ownership, which in turn can support successful management of a shared resource.

At the current rate of progress, there will probably still be 2.8 billion people world-wide without safely managed sanitation by 2030. To incentivise and increase implementation of sustainable faecal sludge management (FSM), especially in low and middle-income countries like Cambodia, human waste must be regarded as a resource. However, planning data, e.g. on the quantities, composition and fate of faecal sludge after leaving households, are inadequate and lack accuracy. The aim of this study was to provide baseline data for effective FSM planning by sanitation stakeholders in Phnom Penh. This was done by quantifying sludge volumes generated, transport logistics and resource recovery potential to incentivise sustainable management. Interviews were conducted with users and emptying and transportation contractors, together with collection of technical data about on-site sanitation systems. Geographical coordinates of household sampling locations and disposal sites were also mapped. The results revealed that Cheung Ek and Kob Srov wetlands are the main recipients of faecal sludge collected in Phnom Penh with the amount of 18,800 m³ and 13,700 m³ annually, respectively. The analysis showed that faecal sludge in Phnom Penh contains valuable resources such as nitrogen (6 tons), phosphorus (13 tons) and energy (148-165 GWh) annually, but in-depth investigations of appropriate treatment options for resource recovery are required. Detailed documentation of the location of potential recoverable resources from faecal sludge would assist decision-makers in developing action plans for sustainable FSM in Phnom Penh and similar cities.

The conventional top-down scope of relying only on centralised sewerage has proven insufficient to reach the entire global population with safely managed sanitation and meet Sustainable Development Goals 6.2. and 6.3 by 2030. Citywide Inclusive Sanitation (CWIS) has emerged as an approach to accelerate progress by considering different technologies and service provision models within the same city to expand sanitation access equitably and sustainably. However, to generate an enabling environment for CWIS to be implemented successfully, regulatory frameworks must be adapted, as they are often unsuited for non-sewered sanitation solutions. By analysing the Colombian case study through a mixed qualitative methodology comprised of a policy review, semi-structured interviews, and workshops with key stakeholders in the urban sanitation sector, the country's regulatory framework was evaluated to determine if it is adequate to implement CWIS. Regulations were identified to pose barriers for CWIS and produced a disabling environment for its application. This research proposes recommendations to adapt the regulatory framework to allow CWIS application in Colombia based on the encountered barriers. This is the first comprehensive study on regulations for CWIS in the Latin American context and therefore provides the basis for further research to understand the dynamics related to effective regulations for CWIS globally.

Black soldier fly larvae (BSFL) are widely used in recycling and upcycling of nutrients in agri-food by-products, but low and inconsistent BSFL rearing performance (i.e. larval growth, bioconversion rate, and substrate reduction) has been identified as a key challenge. The aims of this research were two-fold: (1) validate an existing closed rearing system design; and (2) assess whether a microbial inoculum derived from the rearing residue increases rearing performance. In controlled bench-scale experiments, BSFL were reared on tomato pomace (TP) and white wine pomace (WWP), along with food waste as control substrate. The two aims were assessed based on the following response variables: larval mass, substrate reduction, residue properties (i.e. pH, temperature, moisture content), and larval intestinal and residue microbiota. Higher BSFL mass (by 5.1 mg dry mass) at harvest on WWP and substrate reduction on TP (by 11.7% dry mass) in the closed system compared to the open system confirmed the potential of closed systems for rearing performance improvements of agri-food by-products. The rearing system also affected the residual moisture content and temperature, but only had a small effect on microbiota. Performance improvements by the closed rearing system design may be outweighed by insufficient aeration with pasty substrates and higher operational efforts for aeration and larval separation from the high-moisture residues. In contrast to the rearing system design, addition of the residue-derived microbial inoculum did not result in improved performance, nor did it alter intestinal and residue microbiota. Missing performance improvements could have been due to absent or low numbers of probiotic bacteria. The success of microbial substrate supplementation could be improved by studying effects of larval-associated microbes and developing cultivation methods that selectively amplify the beneficial (yet unknown) members of the microbial community. Our investigations aimed to increase the valorisation of low-value agri-food by-products in BSFL rearing.

Risk-based water safety interventions are one approach to improve drinking water quality and consequently reduce the number of people consuming faecally contaminated water. Despite broad acceptance of water safety planning approaches globally, there is a lack of evidence of their effectiveness for community-managed piped water supplies in rural areas of developing countries. Our research, in the form of a cluster-based controlled pre-post intervention analysis, investigated the impact of a combined water safety intervention on outcomes of microbial water quality, users' perceptions and piped system functionality in rural Nepal. The study enrolled 21 treatment systems and 12 control systems across five districts of the Karnali and Sudurpaschim provinces. Treatment group interventions included field laboratories for microbial analysis, regular monitoring of water quality including sanitary inspections, targeted treatment and infrastructure improvements, household hygiene and water filter promotion, and community training. In certain systems, regular system-level chlorination was implemented. Before and after the interventions, the microbial water quality was measured at multiple points within the water system. This information was complemented by household interviews and sanitary inspections. The main result to emerge from this study is that chlorination is the only identified intervention that led to a significant reduction in E. coli concentration at the point of consumption. Secondly, the effectiveness of other interventions was presumably reduced due to higher contamination at endline in general, brought about by the monsoon. All the interventions had a positive impact on users' perceptions about their water system, as measured by expectations for future functionality, satisfaction with the services received, and awareness of the potential health risks of drinking contaminated water. For future applications we would recommend the more broadly applied use of chlorination methods at system level as a key component of the package of risk-based water safety interventions.

As the world population increases, food demand and agricultural activity will also increase. However, ~30–40% of the food produced today is lost or wasted along the production chain. Increasing food demands would only intensify the existing challenges associated with agri-food waste management. An innovative approach to recover the resources lost along the production chain and convert them into value-added product(s) would be beneficial. An alternative solution is the use of the larvae of the black soldier fly (BSFL), Hermetia illucens L., which can grow and convert a wide range of organic waste materials into insect biomass with use as animal feed, fertilizer and/or bioenergy. However, the main concern when creating an economically viable business is the variability in BSFL bioconversion and processing due to the variability of the substrate. Many factors, such as the nutritional composition of the substrate heavily impact BSFL development. Another concern is that substrates with high lignin and cellulose contents have demonstrated poor digestibility by BSFL. Studies suggest that pretreatment methods may improve the digestibility and biodegradability of the substrate by BSFL. However, a systematic review of existing pretreatment methods that could be used for enhancing the bioconversion of these wastes by BSFL is lacking. This paper provides a state-of-the-art review on the potential pretreatment methods that may improve the digestibility of substrates by BSFL and consequently the production of BSFL. These processes include but are not limited to, physical (e.g., mechanical and thermal), chemical (alkaline treatments), and biological (bacterial and fungal) treatments.

Comprehensive knowledge of faecal sludge characteristics is needed for sludge management planning, but it is lacking for the city of Phnom Penh, Cambodia. Thus, this study characterised physicochemical properties of faecal sludge from households in Phnom Penh and related these to sludge containment unit type, unit age, connectedness to the urban drainage network, type of wastewater captured, watertight containment units, number of users, and emptying practices. In total, 194 faecal sludge samples collected during containment unit emptying were analysed for physicochemical parameters. Information on containment units was collected in a survey of emptiers and users. Mean values of faecal sludge chemical parameters were found to be slightly lower than previously reported values for low-/middle-income countries, whereas physicochemical properties were within similar ranges. The main factor influencing organic matter content in faecal sludge was containment unit connection to the urban drainage network, whereas emptying practice and capture of only blackwater affected nutrient levels. The concentrations of nutrients and organic pollutants greatly exceeded Cambodian discharge standards for wastewater. This causes environmental impacts, so treatment is needed before discharge. The faecal sludge characteristics and influencing factors identified here can serve as a baseline for sanitation stakeholders planning faecal sludge management systems in Phnom Penh and similar cities.

Daily carrying of heavy loads of domestic water, especially during pregnancy and postpartum, bears a threat to maternal health in low-income countries. Using an extended health action process approach (HAPA), we examined women's reasons for and psychosocial determinants of safe water-carrying during pregnancy and postpartum. In a mixed-methods study, trained local interviewers conducted 1001 quantitative interviews with women of reproductive age (n = 921 analyzed) and 21 qualitative interviews with women of reproductive age, in-laws, and spouses in rural Nepal. We analyzed the quantitative data with generalized estimating equations to model the HAPA-based psychosocial determinants of avoiding water-carrying during pregnancy and postpartum. Subjective perspectives were investigated with thematic analysis. Outcome expectancies (B = 0.24), self-efficacy (B = 0.20), and injunctive norms (B = 0.23) were significantly associated with the intention to avoid water-carrying. Self-efficacy (B = 0.36) and instrumental support (B = 0.05) are related to behavior (all p < 0.05). Women explained water-carrying during pregnancy by a lack of family support, a shift of health decision-making power to in-laws, and low behavioral control. Overall, the necessity of water, family decision-making structures, and low support make it difficult for women to discontinue water-carrying. Additionally to infrastructural improvements, behavioral interventions may increase women's self-efficacy for safe water-carrying (e.g. reducing weight) and social support.

In recent years, shared facilities have contributed substantially to increased access to sanitation in urban areas. While shared sanitation is often the only viable option in densely-populated, low-income urban areas, it is currently considered a "limited" solution by the international community. In this paper, we analyze the conditions under which shared sanitation could be considered of adequate quality and propose a set of indicators associated with sanitation quality to be included in national household surveys. We conducted a survey with 3600 households and 2026 observational spot-checks of shared and individual household toilets in Kisumu (Kenya), Kumasi (Ghana), and Dhaka (Bangladesh). We develop a composite sanitation quality outcome measure based on observational data. Using regression analysis, we identify self-reported indicators that correlate with the spot-checked composite measure and are, therefore, robust with regard to reporting bias. Results show that (pour-) flush toilets are a highly informative indicator for sanitation quality compared to other toilet technologies. In contrast to previous arguments and depending on the context, sharing a toilet has a comparatively lower correlation with sanitation quality. Toilets still show good quality if shared among only 2-3 households. Toilet location and lighting, as well as the presence of a lockable door, are equally strong indicators for sanitation quality and could serve as alternative indicators. The findings suggest that the sanitation service levels defined by the WHO and UNICEF might be reconsidered to better capture the quality of sanitation facilities in low-income urban settlements.

In recent years, decentralized composting appeared as one of the most appropriate treatment options for organic waste valorization in low- and middle-income countries. In Cote d'Ivoire, a pilot project has proved the feasibility of organic municipal solid waste composting for the city of Tiassalé. However, numerous issues still need to be addressed for the establishment of a sustainable decentralized composting system in this city. One of the key issues is site selection. Until now, there is no clear model for such plant site selection. In this study, multi-criteria decision analysis (MCDA) and geographical information system (GIS) approaches were combined to develop an appropriate model for selecting decentralized composting sites in the city of Tiassalé. The methodology used involved two different and complementary phases. First, MCDA and GIS techniques were used to identify the most suitable site areas. Seven criteria clustered in three main factors (environmental, social and economic), and five constraints were considered in the analysis process. Second, five sites were selected within the most suitable areas after a basic field visit and ranked using the Analytic Hierarchy Process. The results showed that the most suitable spaces for decentralized composting plant siting represent only 2.6% of the study area. The investigation yielded on the selection of the two best options for decentralized composting plant siting for the city of Tiassalé. This study proved that the combination of MCDA and GIS is a practical and efficient method to identify suitable sites for decentralized composting plants.

Faecal sludge dewatering is often a necessary step in many treatment and reuse processes, and it can decrease costs of transporting large volumes of high water content sludge. Common dewatering methods such as settling-thickening tanks and drying beds are not feasible in space-constrained areas such as urban informal settlements, therefore innovative dewatering methods are needed. This study evaluated permeable membranes as a dewatering method for a transfer station operated by Sanergy in Nairobi, Kenya. The objective was to determine if membranes could provide a sustainable and economically-feasible dewatering method within the constraints of Nairobi’s informal settlements by evaluating multiple variables, such as flocculant dosage and initial total solids content, and their relation to faecal sludge dewatering. Experiments were conducted with several membrane types including commercial geotextiles and locally-produced plastic woven bags (gunny sacks). Increasing the flocculant dosage within an optimal range was seen to increase dewatering rates, but had minimal effect on the final dewatered solids content. Sludge with initial total solids contents below 3% was seen to require longer dewatering times to allow for drainage, while sludge above 3% required a minimal drainage period before evaporation began. A settling step proved paramount for sludge with high water content where the supernatant was then decanted prior to dewatering through permeable membranes; however, this may not be recommended in all cases depending on the treatment objectives. Reuse of geotextile membranes may lead to a reduction in dewatering performance, and single-use, locally-produced membranes are a more cost-effective, though operationally intensive, option.