微波-过氧化氢工艺处理含Cu-EDTA废水

In the present study, microwave-H₂O₂ (MW-H₂O₂) process was applied for the treatment of Cu-EDTA containing wastewater. The effects of reaction time, initial pH, H₂O₂ dosage, microwave power and coexistent substances were investigated in detail. The corresponding degradation mechanism of Cu-EDTA was also described. The results showed that for the elimination of 1.57 mmol•L^-1 Cu-EDTA, the highest removal efficiencies of Cu (97.0%) and TOC (60.7%) were achieved under the optimum conditions (i.e. initial pH 3, H₂O₂ dosage 41 mmol•L^-1, microwave power 210 W, and reaction time 10 min). In this situation, the effluent conductivity decreased to 1.8 mS•cm^-1, and only 0.15 g•L^-1 of the sludge yield was generated. The presence of coexistent substances such as NO₃^- had nearly no effects on the degradation processes, while Cl^-, H₂PO₄^- and tartaric acid were unfavorable to the oxidation degradation of Cu-EDTA. After treated for 4 min, Cu-EDTA was almost totally oxidized to various Cu-intermediates, which rapidly degraded within 4-6 min, leading to the final formation of low molecular organic acids, NH₃-N, and inorganic carbon. The solid sludge mainly presented in the forms of CuO. Compared with traditional Fenton process, MW-H₂O₂ process exhibited more excellent performance in terms of oxidation efficiency, effluent conductivity and sludge yield.