Clearer picture of the formation of transformation products during drinking water treatment thanks to integrated strategies

During drinking water production, biotic and antibiotic processes can form transformation products (TP) from organic micropollutants (OMP). How these substances behave in water treatment and how toxic they are may not necessarily correspond to their parent substances. As a result, monitoring the removal of parent substances alone is inadequate as a way to determine chemical water quality.

For a clearer picture of water quality and changes in that quality as a result of the stages in drinking water treatment, it is necessary to include the formation and identification of toxic TPs that are relevant for public health. Microorganisms active in various drinking water treatment processes can remove OMPs from water. To date, there has been no extensive research looking at this biological removal capacity in processes such as rapid filtration.

In this study, OMP removal and the formation of transformation products were analysed using non-target screening (NTS) in spike-in, pilot-scale, and seven full-scale rapid filters fed with surface water from the Netherlands and Belgium. In the case of the full-scale rapid filters, the chemical analyses were supplemented by surveying the microbial populations in the influent, the filter medium and the effluent. This was done by characterising the genetic material (with 16S rRNA gene amplicon sequencing). To examine the processes affecting OMP removal in detail, these two strategies were integrated.