Department Process Engineering

Bases for technical measures
Within the workpackage “bases for technical measures” several pilot- and lab-scale studies are being conducted in order to elaborate further knowledge about the advanced wastewater treatment technologies for the removal of micropollutants. Promising technologies have to fulfill several criteria:

Elimination capacity: a broad range of micropollutants needs to be removed to a large extent.

No side products: the creation of toxic waste products needs to be avoided.

Applicability: the technology needs to be easy to integrate to the existing wastewater treatment system and easy to operate by the WWTP staff.

Cost-efficiency: Expenses (material, energy, staff and money) need to be within reasonable range.

Preliminary studies pointed out that both, ozonation and adsorption onto powdered activated carbon, are (currently) the most promising technologies. Ozonation is tested in two full-scale pilot studies on WWTP Regensdorf (finished) and WWTP Lausanne (STEP Vidy, ongoing). Adsorption onto powdered activated carbon will also be tested in parallel to the ozonation in Lausanne, but also in smaller pilot projects at Eawag and on the WWTP Kloten-Opfikon. The questions to be answered with the pilot studies are the following:

• What is the elimination capacity of the process?

• How does the wastewater quality change in terms of other parameters like ecotoxicology, pathogens, foaming, odor, etc.?

• Are there any undesired side effects or products (e.g. waste, toxic substances, interference with the biological treatment)

• Is the technology technically and operationally applicable (infrastructure, process engineering, control, safety, ...)

• How much energy is required? What are the costs for construction and Operation?

Many of these investigations are conducted at Eawag or accompanied by Eawag staff. Furthermore, experiences from international projects and cooperations (e.g. EU-project Neptune, Ruhr-study Northrhine-Westfalia) are integrated and exchanged.The project "Strategy Micropoll" is completed. Results are summarized in the final FOEN report (full report in German).