分批投加过氧化氢对电活化过一硫酸盐氧化卡马西平影响研究

Enhanced electrochemical activation of peroxymonosulfate by multiple dosing of hydrogen peroxide

通过分批投加过氧化氢(H_(2)O_(2))强化电活化过一硫酸盐(E-PMS)体系对有机污染物的降解效能。以卡马西平(CBZ)为目标污染物,考察分批投加(Multiple Dosing,MD)H_(2)O_(2)强化E-PMS[E-PMS-H_(2)O_(2)(MD)]体系降解CBZ的效率。分析PMS浓度、电流强度、H_(2)O_(2)投加量对CBZ去除的影响,确定最佳反应条件。探究E-PMS-H_(2)O_(2)(MD)体系降解CBZ过程中存在的活性氧物质和可能的强化机理。结果表明:分批投加H_(2)O_(2)可以明显强化E-PMS体系降解CBZ。在分批投加H_(2)O_(2)总量为13.3 mmol/L、PMS浓度为50 mmol/L、电流强度为500 mA、CBZ质量浓度为10 mg/L条件下,40 min时E-PMS-H_(2)O_(2)(MD)体系对CBZ的去除率可以达到99.14%,而E-PMS体系对CBZ的去除率仅为71.43%。通过淬灭和电子顺磁共振(EPR)试验可确定E-PMS-H_(2)O_(2)(MD)体系中存在硫酸根自由基(·SO_(4)^(-))、羟基自由基(·OH)、单线态氧(~1O_(2))和超氧根自由基(·O_(2)^(-))。其中·O_(2)^(-)不参与氧化CBZ,而是起到活化PMS产生·SO_(4)^(-)的作用。实际水体中的应用结果表明,该体系在实际水体中也有较高的CBZ去除率。

In this study,the performance of the electro-activated peroxymonosulfate(E-PMS) process was enhanced by multiple dosing of hydrogen peroxide(H_(2)O_(2)).Firstly,with carbamazepine(CBZ) as the target pollutant,the removal ratio of CBZ by multiple dosing of H_(2)O_(2) enhanced E-PMS [E-PMS-H_(2)O_(2)(MD)] process was investigated.Secondly,the effects of PMS concentration,current intensity,and H_(2)O_(2) dosage on CBZ removal were analyzed to determine the optimal reaction conditions.Thirdly,the reactive oxygen species present in the E-PMS-H_(2)O_(2)(MD) process were investigated by quenching experiments and electron paramagnetic resonance(EPR) test.In addition,to further reveal the reaction mechanism,the steady-state concentrations of reactive oxygen species in the E-PMS-H_(2)O_(2)(MD) process were determined by degradation experiments of the three probe compounds CBZ,NB,and MeOH.Finally,the removal of CBZ in different water matrices by E-PMS-H_(2)O_(2)(MD) process was investigated.The results showed that multiple dosing of H_(2)O_(2) could significantly enhance the degradation performance of CBZ and PMS decomposition in the E-PMS process.Under the conditions of H_(2)O_(2dosage) of 13.3 mmol/L,PMS concentration of 50 mmol/L,the current intensity of 500 mA,and CBZ concentration of 10 mg/L,the removal ratio of CBZ was 99.14% by the E-PMS-H_(2)O_(2)(MD) within 40 min,while the removal ratio of CBZ was only 71.43% for the E-PMS system.The existence of sulfate radical(·SO~-_4),hydroxyl radical(·OH),singlet oxygen(~1O_(2)),and superoxide radical(·O_(2)~-) were confirmed in the E-PMS-H_(2)O_(2)(MD) process,while ·O_(2)~- was an absence in the E-PMS process.The steady-state concentrations of ·OH and ~1O_(2) in the E-PMS-H_(2)O_(2)(MD) process were almost the same as E-PMS,while the steady-state concentration of ·SO_4~- is 16.3 times higher than that of the E-PMS process,which results in higher removal ratio of CBZ.·O_(2)~-can not oxidize CBZ directly,but serve to activate PMS to produce ·SO_4~-.In different water matrices,the E-PMS-H_(2)O_(2)(MD) process can also achieve an effective removal of CBZ,revealing its strong application potential in actual water.