Effects of coagulation processes on aldehydes formation in groundwater treated with common oxidative agents

This work is concerned with the effects of coagulation processes with two different coagulants (polyaluminum chloride (PACl) and Al2(SO4)3) on aldehydes formation during oxidation with common oxidants (ozone, chlorine and chlorine dioxide) in a particular groundwater source in Northern Banat region, Yugoslavia. Aldehydes concentrations in coagulated water were lower than in raw water. In contrast, obtained results showed that specific contents of these disinfection byproducts (μg mg−1 TOC) showed an increase after coagulation processes in a number of samples. Results indicate that the choice of the coagulant-oxidant combination may be important as well as the type of filtration bed, retention time, and filter washing regime in the removal of aldehydes from water.