Effect of ultrasonic on the oil-containing wastewater´s flocculation treatment

The effect of ultrasonic on the oil-containing wastewater´s flocculation by PAM and PAC as flocculatants were studied. The results indicated that PAM and PAC showed effective flocculating effect on the removal of oil and CODcr from the simulated wastewater, and the experimental optimum conditions for PAM were, dosage 2.0mg/L, pH unbuffered, reaction time 2.0min, precipitation 30min, the removal efficiency of COD and oil achieved 50.03% and 43.3%, respectively. The removal efficiency of COD and oil achieved 43.2% and 37.8% for PAC at the same conditions except the dosage of PAC was 80mg/L. Ultrasonic can degrade the wastewater obviously, and the degradation efficiency increased with the increasing of ultrasonic power and reaction time, removal efficiency of COD and oil were 48.9% and 44.6% under the condition of power 150W, reaction time of 90min. Ultrasonic/ flocculation experiment indicated that ultrasonic enhanced the flocculation effect of PAM and PAC on oil-containing wastewater, the removal efficiency of COD and oil were above 60% under ultrasonic power of 135W, reaction time of 30min, pH unbuffered at the same flocculation conditions above mentioned. However, Ultrasonic and floccalation had no obvious synergy effects on oil-containing wastewater. Then the experimental schemes of first ultrasonic, then flocculation and first flocculation, then ultrasonic were adopted to degrade oil-containning wastewater furtherly, the results showed the effect of ultrasonic and flocculation were correlated with wastewater´s concentration to a great degrees.