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

Abstract

The degradation behavior of polyacrylamide (PAM) solution by low-temperature plasma was investigated, and the effect of some factors that might affect the degradation process was further examined. The PAM solution was treated with low-temperature plasma generated by dielectric barrier discharge (DBD) combined with H₂O₂ and a Mn + Cu/AC composite catalyst. 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 of 1000 mg/L, discharge voltage of 18 kV, H₂O₂ addition of 2%, and catalyst addition of 810 mg. The results indicated that the degradation rate increased with the increase of the catalyst dosage at the same discharge time. The degradation rate of 180 min increases from 90 to 97.6% with an increase in voltage from 16 to 18 kV, and the molecular weight decreases from 2,720,204.23 to 1,370,815.54. The degradation effect caused by the change of H₂O₂ addition was considerable compared with other factors. When the discharge time was 180 min, the degradation rate increased 26.3% with the increase of 1.6% H₂O₂ addition. Under the optimal process conditions, the addition of the catalyst resulted in a more rapid initial decrease in the pH value of the solution compared to the system without the catalyst.

Keywords: DBD; H2O2; Low-temperature plasma; Mn + Cu/AC; Polymer-containing wastewater.