Research on Microwave Irradiation-Fenton Oxidation Coupling Coagulation Process to Treat Dyeing Wastewater

The study was carried out to evaluate the feasibility of microwave irradiation-Fenton oxidation coupling coagulation process to treat the industrial dyeing wastewater. Batch experiments were performed to investigate effects of various experimental parameters such as H₂O₂ concentration (3.6-8.4g/L), FeSO₄·7H₂O concentration (0.06-0.14g/L), microwave power (100-1000W), microwave irradiation time (0.25-5 min), initial pH (2.0-8.0) and PMSi concentration (28.8-76.8 mg/L) on treatment efficiency. Kinetic data revealed that the combined process has obviously efficiency on decoloration of dyeing wastewater. Under the conditions of 4.8g/L H₂O₂, 0.08g/L FeSO₄·7H₂O, 500 W of microwave power, 1 min of microwave irradiation time and 33.6 mg/L PMSi, the removal ratios of colority and COD reached to 98% and 95.96% respectively with massive floccules and rapid sedimentation. The mechanism discussion also indicated the combined process embodied fully the synergetic effect between microwave irradiation, Fenton oxidation and coagulation as a result of the thermal efficiency and non-thermal efficiency of microwave.