RADIOLYTIC DEGRADATION KINETICS OF 2,4-DICHLOROPHENOL IN AQUEOUS SOLUTION BY GAMMA RAY/O_3/H_2O_2

摘要

Under circumstance of irradiation from gamma ray, therndegradation efficiency of 2,4-DCP in aqueous solutionrnwas investigated, and the effects of irradiation dose, therninitial concentration, H_2O_2, O3 on the removal of 2,4-DCPrnwere investigated as well. The results indicated thatrn2,4-dichlorophenol can be decomposed efficiently byrnγ-induced degradation. When the absorbed dose was 6rnkGy, the removal efficiency of 100 mg.L-1 2,4- DCP wasrn99%. And the mineralization degree of 2,4-DCP in thernlow initial concentration condition was higher than that inrna high initial concentration. The combination of gammarnray irradiation and O3 or H_2O_2 oxidation resulted in arnsynergistic effect, which can increase the degradationrnefficiency of 2,4-dichlorophenol. The degradation ofrn2,4-dichlorophenol could be described by first-orderrnreaction model. At 100 mg.L~(-1) initial concentrations, thernremoval efficiency of 2,4-DCP after radiolysis treatmentrnfollowed the following order: irradiation /30 mg.L~(-1)O_3 >rnirradiation/ 175 mg.L~(-1)H_2O_2 > irradiation/ 35 mg.L~(-1)H_2O_2rn> irradiation /13 mg.L~(-1)O_3 > irradiation. And the reactionrnrate constant was 1.2467 h~(?1), 1.1233 h~(?1), 0.7589 h~(?1),rn0.4900 h~(?1) and 0.4426 h~(?1), respectively.