Oxidation of bisphenol A by UV/S_2O_8~(2-); Comparison with UV/H_2O_2

摘要

The UV/S_2O_8~(2-) process was applied to decompose bisphenol A (BPA), which is a representative endocrine-disrupting chemical (EDC), and was comared with the UV/H_2O_2 process. The BPA degradation efficiency by UV/S_2O_8~(2-) was increased by increasing S_2O_8~(2-) concentration or decreasing BPA concentration. The presence of humic acid caused an inhibitory effect. The BPA oxidation rate by UV/S_2O_8~(2-) was increased in the following order: neutral pH (pH_i = 7) < acidic pH (pH_i = 4) < basic pH (pH_i = 10). The main oxidizing species in the UV/S_2O_8~(2-) system was sulphate radical (SO_4~(-*)), whereas the main oxidizing species in the UV/H_2O_2 system was OH radical (OH~*). Compared with UV/H2O2, the UV/S_2O_8~(2-) process showed higher performance for not only BPA degradation but also its mineralization, which means that SO_4~(-*) is a more effective oxidant for BPA than the OH". The results shown in this study imply that the SO_~(-*)-based UV/S_2O_8~(2-) process can be an excellent alternative process for the widely used UV/H_2O_2 process, with higher remediation performance.