By and large, safety agencies currently have no means of detecting this kind of environmental crime on a broad scale. But this illegal sewage poses major challenges for wastewater treatment facility operators and can even result in turnover of the affected wastewater treatment ponds.
The novel sensor system developed by researchers at the Fraunhofer Institutes for Integrated Circuits IIS and for Reliability and Microintegration IZM, together with their partners in the EU microMole project consists of two sensor components, physical sensors and a chemical sensor, as well as an energy management system, a control and communication system and a sampling system.
If tainted wastewater repeatedly causes problems at wastewater treatment plants, safety agencies could examine the sewage system at certain points and, by taking multiple measurements, gradually close in on and ultimately expose the perpetrator.
To take the measurements, a robot places three rings in the sewage pipe. The first ring is positioned directly in front of the suspect company’s inlet and the second directly behind it. Both rings are equipped with a physical sensor for measuring various parameters, such as temperature, pH and water conductivity. The two rings communicate with each other wirelessly and compare the measurement data from their sensors.
Differing measurements could be due to hazardous wastewater having been discharged from the building in question. The third ring, which is mounted a bit further back in the sewage canal, is equipped with a chemical sensor and a sampling system. If the second ring transmits a special signal, these systems “wake up.”