Inactivation of monopylephorus limosus by chloramine, chlorine dioxide, and hydrogen dioxide: Effectiveness and safety

The occurrence of redworms in water supplies raises concerns among consumers regarding the safety of their drinking water. In this study, the inactivation effects of three disinfectants, chloramines, chlorine dioxide (CIO₂), and hydrogen peroxide (H₂O₂), on the redworm (Mono-pylephorus limosus) in tap water were comparatively evaluated. After inactivation, a Photobacterium phosphoreum acute toxicity experiment and a zebrafish embryonic development toxicity experiment were conducted to evaluate the safety of the disinfected water. The results show that chloramines with 4 mg/L residual chlorine has relatively good effect in killing redworm, and the disinfected water maintains low health risks in contrast, the tap water is high toxic after killing redworm with even a low concentration (0.005%) of H₂O₂, suggesting that H₂O₂ is probably not a good disinfectant for controlling redworm in water supply; CIO₂ at 6-8 mg/L level can inactive redworm effectively while the risk of disinfected water to human health remains low. Based on the overall results of disinfection effectiveness, side-effect chemical safety, and practicality, chloramines and CIO₂ appear to be useful in reducing redworm risks in water supplies.