Mobile TOC measuring station for process optimization
Development of a wastewater switch for the energy-efficient selective partial flow treatment of highly concentrated wastewater (ESTA) at municipal wastewater treatment plants
The research association ESTA is a merger of AKUT Umweltschutz Ingenieure Burkard und Partner, the Technical University of Berlin, FG Siedlungswasserwirtschaft and LAR Process Analysers AG. The aim was the development of an intelligent wastewater switch in the inflow of municipal sewage treatment plants for the separation of highly charged inflows and energy recovery by means of anaerobic treatment. The joint project “ESTA (FKZ 02WQ1382A-C)” was funded by the Federal Ministry of Education and Research (BMBF) within the framework of the SME-innovativ funding initiative.
As a result, peak inflow concentrations could be identified and evaluated with a time resolution of 6 minutes with regard to height and frequency in order to activate the wastewater diverter.
A successful operation of the wastewater switch and the anaerobic test reactor was possible despite the low peak concentrations and the low number of shock loads on the investigated wastewater treatment plant in combination with excess sludge. The simulation of the wastewater treatment plant showed that, despite the removal of the highly charged wastewater fraction and despite changes in the C:N ratio, the statutory monitoring values can be complied with under the underlying conditions (in particular the low ammonium inflow values). A maximum degree of electrical self-sufficiency of 75 % could be achieved.
A central component of the project was the construction and operation of a test plant at the Baruth (Brandenburg) sewage treatment plant, which was planned and installed in coordination with the project partners TU Berlin and AKUT. The project partner LAR was mainly responsible for the development of an adapted online analysis technology. Project start was 01.10.2016, project end was 31.03.2019.
With the help of the TOC-Online monitor a mechanism was controlled, which feeds inlet water of the sewage treatment plant to an anaerobic reactor from an adjustable threshold concentration. Both the analysed feed concentrations, the volume flows and loads fed into the reactor and the biogas produced in the reactor were evaluated.
Due to the implementation of the TOC online monitor on a trailer, the measuring equipment is now also available for mobile use. Measurement campaigns at other sewage treatment plants and at two industrial sites prove the operational capability. The basic load could be clearly determined and the concentration peaks could be evaluated with regard to height and frequency. It was possible to define threshold values in concentration and volume of an impact load which makes the investigation of a general conversion of the process with separate anaerobic sludge treatment useful.
“Although the Baruth wastewater treatment plant under investigation with the evaluated impact loads is below the threshold values determined and a further investigation does not appear to be appropriate here, the results of the other sites investigated certainly show potential”, explains project coordinator Dipl. Ing. Thilo Burkard (AKUT).
The participating project partners are accordingly optimistic that the new concept can be applied to new construction and conversion of wastewater treatment plants. A measurement campaign with the mobile measuring device is therefore planned for other wastewater treatment plants.
Further information: Thilo Burkard