Comparison of Disinfection By-Product Formation and Distribution during Breakpoint Chlorination and Chlorine-Based Disinfection in Drinking Water

Breakpoint chlorination (BC) and disinfection with chlorine-based disinfectant are widely used procedures in drinking water production. Both involve dosing chlorine into the raw water, where it can react organic compounds, forming by-products (DBPs) of health concern. However, technological parameters (e.g., contact time, dosage, bromide to residual free ratio) two different, which lead differences DBP formation. To better understand this, a year-long sampling campaign was carried out at three waterworks Hungary, both BC used. confirm results field sampling, bench-scale experiments were out, investigating impact (a) concentration (b) (bromide ratio), (c) time on The measured DBPs trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), chlorate. During BC, formed higher concentration, exception one waterwork having elevated content water. Bromine substitution factors (BSFs) significantly during than laboratory experiments. After chlorate range 0.15–1.1 mg/L, 96% samples exceeded European Union (EU) parametric value (0.25 mg/L), whereas contributed only slightly. Granular activated carbon (GAC) filters remove exhausted after 6–8 months use, first for those chlorinated THMs, generated predominantly BC. biological activity started increase 3–6 operation. This helps biodegradable such as disubstituted acid (DHAAs) HANs, even if adsorption capacity GAC low.