On a QSAR approach for the prediction of priority compound degradation by water treatment processes

Emerging (chemical) substances are increasingly found in water sources and must be removed by water treatment systems. However, the treatment efficiency regarding these substances is often unknown. A promising approach is using QSARs (quantitative structure activity relationships) or QSPRs (quantitative structure property relationships) to correlate the existing knowledge of a compound's chemical structure to water treatment process properties, such as a biological activity or physico-chemical property. As UV/H₂O₂ treatment of water is an important barrier against priority pollutants, a QSAR model has been developed for the prediction of a typical physico-chemical property: i.e. hydroxyl radical reaction constants. Hydroxyl radicals are highly reactive and therefore largely responsible for a compound's degradation during UV/H₂O₂ treatment. A good correlation is found for the training data set. Chemical parameters that were related to charge on C atoms and topology of the compound were found to be important for the hydroxyl radical rate constants. So far, these results look promising, but further research is still required to increase the predictability of the model and to develop QSAR models for other physico-chemical properties.