| Summary: | 碩士 === 國立中興大學 === 環境工程學系所 === 98 === In this study, we apply electrochemical processes to the degradation of chlorophenols in aqueous media. The target pollutants 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP) were conducted by electrokinetic process (EK) and electro-Fenton process (EF)；and removal rate, mineralization and dechlorination for different processes were investigated. Based on the results, Electro-Fenton system has the best rate of producing ferrous ion and hydrogen peroxide at electric density of 0.75 mA/cm2 and air flow of 0.7 mL/min. The synthesis mass of hydrogen peroxide by EF process followed linear relation with time at the first 30 min which was 0.65 mg-H2O2/min. According to the results of batch experimental, all electrochemical processes have great efficiency in the removal of chlorophenols in aqueous media in this study. Among these processes, the Electro-Fenton process have the best treatment efficiency, that 2,4-DCP and PCP residual rate was 19.8 and 35.9%, and mineralization efficiency was 78.7 and 63.8%, respectively after 180 min. Lengthening treatment time can enhance the removal efficiency, that increase 10.2 and 1.3 times for 2,4-DCP and PCP, respectively. Under the same operating conditions, the order of removal efficiency is EF>EK4 (Electrokinetic, pH 4)>EK10 (Electrokinetic, pH 10)>EFL (Electo-Fenton-like)；the mineralization efficiency is EF> EK4> EK10> EFL; the dechlorination efficiency is EF>EK4≒EFL>EK10. Application of optimum conditions in treatment of true groundwater pollution, the removal rate and mineralization efficiency was 81.29 and 77. 50% for 2,4-DCP and 77.49 and 54.71% for PCP, respectively. Proved by the experimental results, Electro-Fenton process is really suitable for remediation of chlorophenols in groundwater.
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