Treatment of 4-chlorobenzoic acid by plasma-based advanced oxidation processes

•The degradation of 4-CBA is better when the DBD reactor is used as AOP than Glidarc.•The production of NOx in the gas phase can influence the degradation process.•Utilization of DBD discharge in air can reduce the NOx production.•Presence of corrosion reaction (Brass) decreases the efficiency of the treatment process.•The material which is used in the AOP can influence the final efficiency of the treatment.

Studies show that oxidation resistant pollutants are present after conventional water treatment systems. Nowadays a new class of oxidation processes is studied: advanced oxidation processes. Our process is based on the use of an electrical discharge (Glidarc and DBD) to produce HO, which is generated on the surface of a thin film of water. The first results show that the DBD is more efficient than the Glidarc with a degradation efficiency of the target pollutant (4-chlorobenzoic acid (pCBA)) of about 0.87 g kWh−1 for DBD and 0.16 g kWh−1 for gliding arc discharge. However, it appears that secondary reactions due to corrosion of the metallic micro-structured plate cause slower degradation of the pollutant. Moreover, the presence of nitrates in solution after treatment indicates the formation of NOx in the discharge and the possible formation of nitrogenous oxidation by-products.