Deactivation of Caenorhabditis elegans nematodes in drinking water by PMS/UV-C: efficiency and mechanisms

The occurrence and infestations of chlorine-resistant invertebrates in drinking water distributions have attracted concerns on water quality in China, making effective deactivation imperative. This study presents a novel strategy for nematode (Caenorhabditis elegans) deactivation using peroxymonosulfate (PMS)/UV-C. The results indicated that 100% deactivation efficiency was obtained under optimal conditions. An acidic pH and 0.25 mg/L Fe(II) were beneficial to the PMS/UV-C-triggered deactivation of nematodes. A mechanism study demonstrated that [Formula: see text] was activated by UV-C to produce ·OH and [Formula: see text], which resulted in oxidative stress and stimulated the occurrence of cell apoptosis, leading to nematode deactivation. The results reveal PMS/UV-C as an alternative to chlorination in water treatment plants (WTP) or an emergency application when chlorine-resistant invertebrates breed in a second-supply water tank is a promising strategy for disinfection. This approach possessed the advantages of avoiding the production of chlorine disinfection by-products (DBP) and greater efficacy of nematode deactivation. This work will provide ideas for on-going research efforts into chlorine-resistant invertebrate deactivation and eventually achieve the direct drinking of municipal tap water.