Contemporary issues on the occurrence and removal of disinfection byproducts in drinking water - A review

Abstract Due to the fluctuating quantity and quality of organic matter (OM) in surface waters, continuous characterisation and the evaluation of its propensity to form disinfection byproducts (DBPs) is essential. The characteristics of OM affects the removal efficiency and influences its reactivity with disinfectants to form DBPs. Research on DBPs is interesting because of their potential carcinogenic health risks. Although the link between DBP precursors such as natural organic matter (NOM) and DBP formation is well established, knowledge on the individual NOM fractions and other DBP precursors responsible for various DBPs is poor. Moreover, data on other precursors of DBPs has not been synthesized. The aim of this paper is therefore to review literature on the quantity and quality of NOM and other DBP precursors, evaluate the formation and treatability of the individual NOM fractions, and establish their influence on the DBPs formation. Possible removal processes for DBPs and their precursors, along with their economic feasibility were discussed. The key findings were: (1) certain fractions of NOM play a pivotal role in the formation of DBPs, (2) commonly used DBP control approaches include post-formation treatment, while targeting the removal of specific DBP precursors is hard to achieve, and (3) membrane technologies, enhanced coagulation, and advanced oxidation processes (AOPs) are effective in removing NOM, although AOP technologies are generally not economically feasible and still need further development and up-scaling. Future research should focus on: (1) toxicological studies to establish public health risks associated with specific emerging DBPs, (2) providing sufficient empirical data to determine whether to regulate currently unregulated DBPs, and (3) economic analyses to inform implementation of DBP precursor removal methods such as AOPs.