3种单氯酚的电化学还原脱氯速率比较

Comparison of Dechlorination Rates of Three Monochlorophenols in Electrochemical Reduction

采用电化学沉积法制备了钯/聚吡咯-十二烷基苯磺酸钠/钛(Pd/PPy-SDBS/Ti)电极,并用于2-氯酚(2-CP)、3-氯酚(3-CP)和4-氯酚(4-CP)3种同分异构体的电化学还原脱氯.探讨了电流、初始p H值和浓度对2-CP脱氯过程的影响,并在同一条件下对3种单氯酚进行了脱氯速率比较.实验结果表明:25℃、电流为5m A、p H值为2.4的条件下反应60min,100mg/L的2-CP被完全去除.根据数据进行拟合,单氯酚的反应过程符合准一级动力学,2-CP、3-CP、4-CP的电化学还原脱氯速率常数分别为6.393×10-2、6.668×10-2、6.990×10-2min-1,脱氯难易顺序为2-CP>3-CP>4-CP.

Pd/polypyrrole-sodium dodecyl benzene sulfonate / meshed Ti( Pd / PPy-SDBS / Ti)electrode was prepared by electrodeposition method and employed to dechlorinate three monochlorophenol isomers including 2-chlorophenol( 2-CP),3-chlorophenol( 3-CP) and 4-chlorophenol( 4-CP). The impacts of current,p H and concentration on the dechlorination process of 2-CP were investigated and the current of 5m A and the initial p H of 2. 4 were selected to be the optimized dechlorination conditions,under which 2-CP with a concentration of100 mg / L could be completely removed within 60 min. The degradation difficulty of monochlorophenols is 2-CP > 3-CP > 4-CP. The reaction processes of three monochlorophenols follow pseudo first order kinetics and the observed reaction rate constants of 2-CP,3-CP,4-CP are 6. 393 × 10- 2,6. 668 × 10- 2and 6. 990 × 10- 2min- 1,respectively.