Biofilm-Derived Disinfection Byproducts in Water Distribution: Precursor Roles and Toxicity under Various Disinfection Methods.

Cl induced the weakest adverse effects. Although disinfection altered the content and proportion of proteins, polysaccharides, and deoxyribonucleic acid (DNA) in biofilms, these changes alone could not fully explain the observed DBP formation patterns. Targeted analysis identified ten major biofilm components, including d-glucosamine, 2-deoxy-d-ribose, and several amino acids. However, their contribution to the formation of the aforementioned DBPs was generally low, indicating that uncharacterized precursors predominated in most scenarios. Despite their limited quantitative contribution, potential reaction pathways for four amino acids with high DBP formation potential were summarized. The contribution of specific biofilm components to DBP formation identified and evaluated in this paper provides important insights for DBP control in DWDS.