Study on catalytic degradation of wastewater containing Polyacrylamide catalyzed by non-thermal plasma-H2O2-Mn+Fe/AC

Polyacrylamide (PAM) is extensively utilized in oilfield polymer flooding for enhanced oil recovery, owing to its high molecular weight and the resulting high viscosity in low-concentration aqueous solutions. However, the increased exploitation of oilfields has led to a rise in wastewater volumes containing PAM. The dielectric barrier discharge (DBD) technology is commonly employed for wastewater degradation due to its high selectivity, minimal by-products, and strong adaptability. The research employs non-thermal plasma-H2O2-Mn+Fe/AC oxidation to treat PAM solution. Elemental composition analysis of the catalyst pre-and post-degradation reveals changes, particularly a reduction in iron content. The experimental findings revealed that the optimum process conditions for the degradation of PAM solution by non-thermal plasma-H2O2−Mn+Fe/AC oxidation were initial concentration of 1000 mg/L, discharge voltage of 18 kV, H2O2 vol concentration of 2 % and catalyst addition of 945 mg. The amount of catalyst addition and the volume concentration of H2O2 have little effect on the kinetic viscosity and pH value. The elemental composition of the catalyst remains largely similar to its pre-degradation state after degradation, except for a noticeable reduction in iron content. The DBD technology was demonstrated to be an effective treatment technology with minimal secondary pollution for which could be applied to wastewater recovery from different oil fields.