Upgrading water treatment trains to comply with the disinfection by-products standards introduced by the Directive (EU) 2020/2184

The EU Drinking Water Directive (2020/2184) adds standards for new disinfection by-products (DBPs) such as haloacetic acids, chlorite, and chlorate, in addition to trihalomethanes and bromate. Therefore, the upgrade of water treatment plants (WTPs) to meet the new standards may be necessary. The objective of this study is to assess approaches for enhancing conventional WTPs to minimize the formation of these just regulated DBPs. Three key strategies are identified: (1) enhanced precursor removal; (2) alternative disinfection/ preoxidation and (3) removal of already-for med DBP. The advantages and disadvantages of such strategies are discussed, considering the formation of other emerging, unregulated DBPs. Guidelines are presented to select the most appropriate treatment trains that are proposed to upgrade the conventional WTPs.