Study on the Degradation Effect of PAA Activated by Fe2+and Electrocoagulation on SMX
Sulfamethoxazole(SMX)is selected as the research object to investigate the effect of electrocoagulation activa-tion of peracetic acid(EC/PAA)on the degradation of SMX,and the buffering capacity of the EC/PAA system and the mechanism of SMX degradation are also explored.The results show that the EC/PAA system could degrade 96％of SMX within 20 minutes under the optimal experimental conditions as initial pH value of 7,electrolyte Na2SO4 concentration of 50 mmol/L,PAA concentration of 10 mg/L,SMX concentration of 3 mg/L,initial current intensity of 60 mA,and elec-trode spacing of 2 cm.The coexisting H2O2 and PAA in the solution can produce a synergistic effect with a synergistic co-efficient SI of 30.125 0.When the initial pH value of the reaction is between 4 and 8,the pH value can be buffered to around 7 after the reaction,indicating that the system has good pH buffering and electrocoagulation effects;but the degra-dation of SMX by Fe2+/PAA system is mainly achieved by changing the solution pH,without buffering effect.According to electron paramagnetic resonance(EPR)identification,the active species in the EC/PAA buffer system are mainly OH,organic free radicals(CH3COO·and CH3COOO·),and 1O2,with the majority being hydroxyl radical(·OH).These free radicals work together to degrade SMX.
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