Heterogeneous Fenton reaction for landfill leachate degradation of active carbon/Cu and active carbon/Fe catalysts through microwave induced method
微波诱导AC/Cu、AC/Fe催化非均相Fenton 反应催化降解垃圾渗滤液

Based on the two catalysts(AC/Cu and AC/Fe) and their heterogeneous Fenton reaction, the activity of the catalysts loaded with Cu and Fe were investigated by carrying out the degradation of landfill leachate in aqueous suspension under microwave induced condition. The results showed that active carbon impregnated with satisfactory concentration of nitric acid before the composite catalysts were prepared could make the COD removal rate of landfill leachate increase by more than 15%. With the increasing of metal loaded on the active carbon, the COD removal rate of landfill leachate by catalyst increased firstly and then decreased. The optimum loading of copper and iron were 2.11 wt%, 1.12 wt%, respectively. As far as AC-Cu system was concerned, the COD removal rate of landfill leachate was up to 84.13% under the certain conditions: initial pH 3, H2O2 dosage of 4.98×103 mg/L, the AC-Cu catalyst dosage of 5.0×103 mg/L, microwave radiation time of 10 min at 420 W power level. For the AC-Fe system, the COD removal rate of landfill leachate was up to 60.16% under the certain conditions: initial pH 3, H2O2 dosage of 0.33×103 mg/L, the AC-Fe catalyst dosage of 20×104 mg/L, microwave radiation time of 10 min at 420 W power level. The COD removal rate of landfill leachate with catalyst AC-Cu and AC-Fe was different, the reason was that the threshold of single molecule distribution on surfaces of AC-Cu catalyst was higher than that of AC-Fe. Inflection points existed in the changes of COD removal with pH for AC-Cu system and AC-Fe system, and pH was 3 corresponding to the highest COD removal. When microwave radiation power level was low, COD removal increased with microwave radiation power. And the catalytic activity was inhibited with microwave radiation power increasing at high power level, which resulted from the degradation of organic sulfide in landfill leachate, and forming into inorganic sulfur compounds. The COD removal rate of landfill leachate was found to strongly depend on the reaction pH, and the optimum pH was 3 in both systems.