Oxidation of Tris (2-chloroethyl) phosphate in aqueous solution by UV-activated peroxymonosulfate: Kinetics, water matrix effects, degradation products and reaction pathways

摘要

The feasibility of UV-activated peroxymonosulfate (PMS) technology for the degradation of Tris (2-chloroethyl) phosphate (TCEP) in an aqueous solution was investigated in this study. The conditions of [PMS](0): [TCEP](0) = 20:1, T = 25 +/- 2 degrees C and pH = 5.5 +/- 0.5 cause a 94.6% removal of TCEP (1 mg L-1) after 30 min of Hg lamp irradiation. The effects of operating parameters (the oxidant doses, pH and presence of typical cations (Fe3+, Cu2+, Ni2+, NH4+), anions (Cl-, HCO3-, NO3-, HPO42-) and humic acid (HA)) were evaluated. It was found that an increase of the PMS dose and the presence of Fe3+ could accelerate the reaction, while the anions and HA inhibited the reaction. Meanwhile, TCEP removal in various water matrices was compared, and the order for TCEP removal was as follows: ultrapure water > tap water > synthetic water > secondary clarifier effluent > Jiuxiang river water. Twenty-two oxidation products were identified using an electrospray time-of-flight mass spectrometer, and the degradation pathways mainly involved radicals' addition and C-O bond cleavage. Furthermore, ECOSAR analysis revealed that the intermediate products during the TCEP oxidation process were generally not harmful to three typical aquatic species. Hence, UV/PMS can be used as an efficient technology to treat TCEP-containing water and wastewaters. (C) 2017 Elsevier Ltd. All rights reserved.