Study on synergistic catalytic degradation of wastewater containing polyacrylamide catalyzed by low temperature plasma-H2O2

Abstract

Abstract Low temperature plasma technology shows promise in sewage treatment with its advantages of high degradation efficiency, simple operation, and fewer by-products. In this study, a self-built Dielectric Barrier Discharge (DBD) plasma degradation experimental platform was utilized to simulate polymer-containing wastewater from an oilfield using a polyacrylamide (PAM) solution. The PAM solution was treated with low temperature plasma generated by dielectric barrier discharge combined with H2O2 and a Mn + Cu/AC composite catalyst. The effects of different catalyst dosage, H2O2 addition amount, DBD voltage on the degradation rate of polyacrylamide, molecular weight of solution, PH value of solution and solution viscosity were studied. The characterization of the polyacrylamide and composite catalyst before and after degradation was also conducted. The optimal conditions for the oxidation degradation of a PAM solution using low temperature plasma-H2O2-Mn + Cu/AC were determined as follows:: initial concentration 1000 mg/L, discharge voltage 18 kV, H2O2 addition of 2% and catalyst addition of 810 mg. Increasing the catalyst dosage resulted in higher degradation rates, as well as decreased dynamic viscosity, pH value, and molecular weight of the solution. Under these conditions, the degradation rates of 60 min, 180 min and 300 min were 71.4%, 97.6% and 98.6%, respectively.