Degradation and mineralization of 2-chlorobiphenyl by gamma radiation-activated persulfate system

In this study, the degradation and mineralization of 2-chlorobiphenyl (2-PCB) by gamma irradiation were investigated in the presence of persulfate (PS), to examine the synergistic effect of radiation and persulfate oxidation. The results showed that the absorbed dose required for complete removal of 2-PCB decreased in the presence of PS. In addition, compared to a single irradiation system, the removal efficiency and mineralization of 2-PCB in deionized water , groundwater, and secondary effluent increased when irradiation combined with PS. 2-PCB at concentration of 4 mg L −1 to 8 mg L −1 could be efficiently degraded at a wide pH range (3.0–9.5) in irradiation-activated PS (irradiation/PS) system. The presence of 10 mM or 100 mM of Cl − , NO 3 − , CO 3 2− , and SO 4 2− in irradiation/PS system had no obvious influence on 2-PCB removal. 2-PCB was degraded under the combined action of sulfate radicals (SO 4 •− ) and hydroxyl radicals (·OH), in which ·OH contributed more. The irradiation/PS system is promising to treat PCB-containing wastewater.