Micropollutants in the aquatic enviroment

Project No. 6

Elimination of pharmaceutical residues in municipal wastewater treatment plants

In the course of the project two processes to the advanced removal of pharmaceutical residues and organic micropollutants will be converted in large-scale plants and undergo field-tests: the oxidation by means of ozone and the adsorption to activated carbon, in each case as an integration in the conventional process of the municipal sewage treatment. On three municipal wastewater treatment plants (WWTPs), the WWTP Schwerte of the Ruhrverband, the WWTP Bad Sassendorf of the Lippeverband and the WWTP Duisburg-Vierlinden of the Wirtschaftsbetriebe Duisburg AöR, an ozonation will be applied to the effluent of the conventional biological treatment stages. On the WWTP Schwerte powdered activated carbon will supplementary be admixed to a recirculation flow– also in combination with the ozonation. The three wastewater treatment plants differ in regard to wastewater composition, the ozone dosage, the control and measuring technology, the subsequent treatment after the ozonation as well as the usage of activated carbon. Therefore a wide range of application is covered, which allows to expect representative results. The investigation of the advanced oxidation processes with ozone and the adsorption to activated carbon should enable reliable and transferable conclusions about the elimination behaviour of selected micropollutants, the operational feasibility on mechanical-biological sewage plants and the economic efficiency in comparison to other process approaches to the elimination of micropollutants from the water resources cycle. Within the scope of the projected investigations under practical operating conditions, requirements and guidelines will be developed for dimensioning, planning and operation of the ozonation and the addition of powdered activated carbon. A cost/efficiency analysis will provide basis for cost-optimised dimensioning and planning as well as hints for the operation of these processes. Besides, control variables and influencing parameters will be determined in large-scale technical application. Thus removal rates of the micropollutants can be estimated as a function of ozone-dose and addition of activated carbon. Hence, several operation algorithms and regulation algorithms are examined and valued regarding their suitability in large-scale plants.