Department Urban Water Management
Development of non-contact sensors to monitor the wastewater quality in sewers.
Monitoring the urban drainage is a major challenge
Our urban sanitation systems use sewers, i.e., a pipe network, to lead the effluents to the treatment plants. Although we can measure water pollutant concentrations in treatment plants, the collection of data from the sewer infrastructure is more challenging due to the harsh conditions in the sewers. Better monitoring of sewer water quality can provide essential information to improve the management of sanitation systems. This is especially relevant after rain events, which can cause wastewater treatment plants to be overwhelmed with the quantity of effluents to treat, which leads to the release of polluted waters into the environment.
The European Co-UDlabs project primarily focuses on improving sewer management. In particular, the project emphasizes the need for "a transition from the current inefficient approach" and "more robust, autonomous, and interconnected smart monitoring techniques and digital water data analysis tools." One of the project's objectives is to develop new sensors to better monitor the network.
Wastewater measurement devices
To measure wastewater parameters like contamination concentrations, conventional methods involve either the immersion of sensors or the collection of samples. In both cases, contact with the effluents is necessary. This leads to issues such as sensor deterioration or clogging. The sensors need regular inspection and maintenance and therefore have to be accessible, which explains why it is so hard to collect data from sewers. However, the development of non-contact sensors such as radars and ultrasonic devices has addressed these issues, enabling the measurement of water velocity and water level in sewers with minimal maintenance required.
Research project: developing innovative non-contact techniques to monitor sewer parameter such as COD and turbidity
Assessing the potential of reflection-based spectrophotometry for wastewater monitoring is the goal of this PhD. The premise behind this measurement method is that the composition of the water influences the way light reflects off its surface. Although spectrophotometry is already widely used to analyze wastewater’s pollutants, particularly through the measurement of light absorption, the analysis of reflection spectra is relatively new.
This innovative method allows for the monitoring of sewer parameters without any contact with the wastewater. However, it is still in its early stages of development. To this day, this setup has only been tested in laboratories. This configuration is very far from the sewer, where the effluents are in motion and have a complex and variable composition. Therefore, the primary goal of this PhD is to address the challenges associated with implementing this system in a significantly more complex setting. A big part of the project is also to develop an efficient algorithm to analyze the measured spectra. This PhD will be conducted under the supervision of Dr. Jörg Rieckermann, in collaboration with the Co-UDlabs project.
