Study on degradation of wastewater containing PAM catalyzed by nonequilibrium plasma and γ-Al2O3

Abstract

Polymer flooding not only improves oil recovery, but also produces wastewater containing polyacrylamide (PAM). It has the characteristics of high emulsification, high viscosity and difficult degradation. It is necessary to study the degradation of wastewater containing polyacrylamide. A set of dielectric barrier discharge liquid-phase reaction device with circulating cooling function is developed in this paper. The plasma produced by dielectric barrier discharge is carried out, and the degradation of wastewater containing polyacrylamide is experimentally studied under the synergistic effect of catalyst γ-Al2O3. We studied the degradation rate, viscosity and pH of PAM solution under the conditions of different γ-Al2O3 catalyst additions. The morphological changes of polyacrylamide and catalyst γ-Al2O3 before and after DBD catalytic degradation were studied by environmental electron microscope scanner (ESEM), and the catalyst γ-Al2O3 before and after DBD catalytic degradation was characterized by energy dispersive X-ray spectrometer (EDS). The results showed that the degradation rate of PAM solution was 81 % when the discharge time was 300 min and the addition amount of γ-Al2O3 was 375 mg, the discharge voltage was 18 KV and the discharge frequency was 10 KHZ. At this point the apparent shear viscosity of the PAM solution is close to 0. The pH value of PAM was 3 after 30 min discharge time, and decreased to 1.4 after 60 min discharge time. Most of PAM had been degraded into small molecules after 300 min of discharge.