Degradation of Tris (2-Chloroethyl) Phosphate via UV/Fe(III) Photocatalysis: Kinetics, Products, and Toxicity Assessment

In this research, the feasibility of UV/Fe(III) photocatalytic technology for the degradation of tris (2-chloroethyl) phosphate (TCEP) was investigated. Experimental results showed that TCEP had a significant removal efficiency in UV/Fe(III) ([TCEP] 0  = 10 ppm, [Fe 2 (SO 4 ) 3 ] 0  = 0.5 mM, near-100% degradation rate after 90 min). A free radical scavenging experiment and EPR detection indicated that the formation of ·OH by the Fe(III) under ultraviolet light played a major role. Experiments on influencing factors revealed that oxygen accelerated the degradation of TCEP by accelerating the Fe(II)/Fe(III) cycle, but Cl − and PO 4 3− inhibited TCEP degradation. Three intermediate products were generated, including C 4 H 9 Cl 2 O 4 P (product A, m/z 222.9690), C 6 H 13 Cl 2 O 5 P (product B, m/z 266.9954), and C 2 H 6 ClO 4 P (product C, m/z 160.9762). Moreover, the degradation pathways primarily involved the C–Cl bond and phosphoric center being attacked. Escherichia coli toxicity test revealed that UV/Fe(III) treatment reduced environmental risk of TCEP. Therefore, UV/Fe(III) photocatalysis is a promising technique for TCEP control in wastewater treatment. Graphical abstract