Photodegradation of Tri (2-chloroethyl) Phosphate in Aqueous Solution by UV/H_2O_2

摘要

The photooxidation degradation of tri (2-chloroethyl) phosphate (TCEP) by combining UV with hydrogen peroxide as oxidant was primarily studied in the present study by evaluating various treatment parameters. The results suggested that light intensity, initial pH and concentration of TCEP and H_2O_2, and reaction time affected the degradation efficiency of TCEP. The total organic carbon (TOC) removal rates, and the yield rates of Cl~-and PO_4~3 reached up to 86 %, 94 % and 97 %, respectively, under the optimized conditions in the present study. The degradation process obeyed the pseudo-first-order kinetic reaction expressed as In (C_t/C_0)=-0.0275 t with a R2 of 0.9962. The addition of t-butanol indicated that hydroxyl radicals played an important role in the degradation of TCEP. The primary investigation of the degradation mechanism of TCEP suggested that TCEP molecules were attacked by hydroxyl radicals produced from H_2O_2 with the irradiation of UV light, PO_4~(3-) , CFand chlorinated alcohol/aldehyde, and/or non-chlorinated aldehyde with small molecular weight were produced, these produced small organic molecules were furthered oxidized to acids, most of them were finally mineralized to CO_2 and H_2O. The present technology was successfully applied for degrading TCEP in simulated real wastewater, which shows a promising potential for treating similar contaminants using corresponding advanced oxidation technology.