Emulsion wastewater treatment with microwave irradiation technology

The treatment process for emulsion wastewater was conducted by using microwave irradiation technology. The effects of microwave power, irradiation time, settling time and pH on demulsification were investigated. Under the optimum condition that pH range was 2-3, microwave power was 600 W, irradiation time was 1 min, and settling time was 1 h, the COD removal rates could come up to 70%-75%. In addition, the effects of initial COD and fast cooling on demulsification were studied. The result showed that initial COD did not affect the process obviously, and heat exchange of inlet and outlet water was feasible to save energy. The three treatment processes acidification, direct microwave irradiation and microwave-assisted demulsification were compared. The result showed that microwave technology of assisted demulsification was effective in combination with sulfuric acid, and there was a synergistic effect between H⁺ and microwave energy accelerating the demulsification process.