Electro-Fenton (EF) coupled with Pulsed alternating current coagulation (PACC) is an effective technology for the treatment of Cu2+-organic wastewater. In this study, the removal efficiency (Re), electrical energy consumption (EEC) and removal mechanism of Cu2+-organic were analyzed and the optimal operation parameters were determined. SEM, EDS, XRD and FTIR were used to characterize the morphology, elemental composition, crystal structure, function groups of sludge produced in the EF-PACC. UV, ESR and GC-MS were employed to determine concentration of organic matter, existence of OH, middle products of decomposed organic matter in EF-PACC, respectively. The results show that under the optimal conditions of initial pH = 2.5, current density (j) = 2 A/m2, initial c(Cu2+) = 50 mg/L, c(chemical oxygen demand, COD) = 500 mg/L, c[H2O2] = 10 mL/L, frequency (f) = 1 Hz, t = 20 min, the Re(Cu2+) can reach 99.59%. Re(COD) is 90.21%, EEC 1.695 × 10-1 kWh/m3, and the amount of produced sludge (Ws) is 0.9283 kg/m3. Compared with single EF and PACC processes, the order of treatment efficiency is EF-PACC > EF > PACC. EF-PACC technique was a highly effective method in the treatment of Cu2+-organic compound wastewater. The EF-PACC coupled process includes that electrolyzed Fe3+ produces electrocoagulation and OH produces degradation of organic compounds. The combined action of the two effects can effectively remove Cu2+-organic from wastewater.
Keywords: Cu(2+)-organic; Electro fenton; Operation parameters; Pulse alternating current coagulation; Removal mechanism.
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