Efficient degradation of ethanolamine by UV/chlorine process via organic chloramine photolysis: Kinetics, products, and implications for ethanolamine wastewater treatment

摘要: Abstract The degradation of ethanolamine (ETA), a recalcitrant pollutant containing primary amine moiety, can be significantly enhanced in water treatment with chlorination followed by UV (UV/chlorine) via photolysis the N–Cl bond monochloro- (N-Cl ETA) and dichloro-ethanolamine (N-Cl2 which are formed from reaction chlorine ETA. This study investigated kinetics, products, mechanisms ETA UV254/chlorine effects process variables on ETA’s efficiency. Fluence-based, rate constant (kUV) was 1.0 × 10−3 cm2/mJ for N-Cl 1.3 × 10−3 cm2/mJ N-Cl2 UV/chlorine found effective at treating under wide-ranging conditions free available (FAC) dose over concentration (i.e., [FAC]0/[ETA]0 ≥ 1), pre-chlorination duration >a few minutes), solution pH 2–11), due to rapid formation HOCl (k 1.2 × 108 M−1 s−1). Increasing FAC capable enhancing so that it attained kUV 1.5 × 10−3 cm2/mJ [FAC]0/[ETA]0 3, mainly (≥75%) lesser extent involved OH reaction. energy consumption achieve 90% abatement ranged 0.22 kWh/m3 ([ETA]0 = 0.025 mM) 3.59 kWh/m3 ([ETA]0 = 10 mM). Ammonia, formaldehyde, glycolaldehyde were major products ETA, could have through bonds forming aminyl radicals their transformation 1,2-hydrogen shift β-scission. Overall, this provides useful kinetic mechanistic information designing an wastewater.