Novel test procedure to evaluate the treatability of wastewater with ozone

摘要

Organic micropollutants such as pharmaceuticals, estrogens or pesticides enter the environment continuously through the effluent of municipal wastewater treatment plants (WWTPs). Enhanced treatment of wastewater (WW) by ozone (O-3) is probably one of the simplest measures for abatement of organic micropollutants to avoid their discharge to the aquatic environment. During zonation most organic micropollutants present in treated WW are oxidized either by a direct reaction with O-3 or by secondarily formed hydroxyl radicals ((OH)-O-center dot). However, undesired oxidation by-products from the oxidative transformation of matrix components can also be formed. A modular laboratory decision tool based on the findings of previous investigations is presented to test the feasibility of zonation as an option to upgrade specific WWTPs. These modules consist of investigations to assess (i) the matrix effects on ozone stability, (ii) the efficiency of micropollutant removal, (iii) the oxidation by-product formation, as well as (iv) bioassays to measure specific and unspecific toxicity of the treated WWs.