A workflow was developed for the analytical-chemical characterisation and toxicological investigation of biological or oxidative transformation products. The overall concept includes investigations on genotoxicity and mutagenicity, thereby supplying valuable data to assess water quality.
Just a few years ago, the effectiveness of treatment measures to eliminate organic micropollutants was measured only using substance degradation curves. This often disregarded the fact that oxidative or biological processes would not generally cause mineralisation of organic micropollutants but that several stable transformation products could potentially be formed. Recently, the water industry has focused increasingly on clarifying the structure and assessing these transformation products. It is hardly possible to conduct a human-toxicological evaluation of transformation products and metabolites only knowing the molecular structure. It requires additional biological testing.
In the project, as part of a risk-based overall concept, tools were created to handle organic micropollutants in the drinking water supply sector. Model substances were investigated that are relevant to waterworks and form transformation products following biological degradation or oxidative treatment.
Enrichment, separation and detection techniques were established to provide more information on the products. For the biological test methods, the transformation products or reaction mixtures were concentrated using suitable sample enrichment methods and analysed using four toxicological processes (micronucleus test, comet assay, umu-test and Ames test). Finally, the transferability of the findings from the lab experiments was checked by investigating real samples.
E.M. Buchner, O. Happel, C.K. Schmidt, M. Scheuer, B. Schmutz, M. Kramer, M. Knauer, S. Gartiser, H. Hollert, Approach for analytical characterization and toxicological assessment of ozonation products in drinking water on the example of acesulfame, Water Research, 2019, 135, 357-368.