Solar photolysis kinetics of disinfection byproducts

摘要: Abstract Disinfection byproducts (DBPs) discharged from wastewater treatment plants may impair aquatic ecosystems and downstream drinking-water quality. Sunlight photolysis, as one process by which DBPs dissipate in the receiving surface water, was investigated. Outdoor natural sunlight experiments were conducted water for a series of carbonaceous (trihalomethanes, haloacetic acids, halopropanones, haloacetaldehydes) nitrogenous (nitrosamines, halonitromethanes, haloacetonitriles). Their pseudo-first-order rate constants photolytic degradation then used to calibrate quantitative structure–activity relationship (QSAR) parameters, which, return, predicted photolysis potentials other or related compounds. Nitrogenous found be more susceptible solar irradiation than DBPs, with general rankings functional groups follows: N-nitroso (N-NO) > nitro (NO 2 ) > nitrile (C N) > carbonyl O) > carboxyl (COOH). Compounds containing high degree halogenation (e.g., three halogens) usually less stable halogenated species those two halogens). Bromine- iodine-substituted photosensitive chlorinated analogs. While most bromine- chlorine-containing trihalomethanes acids persisted over 6-h test, nearly complete removal (>99%) nitrosamines occurred within 1 h exposure. Indoor laboratory using simulated demonstrated that ∼50% slower when organic matter present, ∼11% non-filtered filtered water.