Removal efficiency and energy consumption optimization for carbamazepine degradation in wastewater by electrohydraulic discharge

Abstract

OBJECTIVEThe treatment of recalcitrant emerging pollutants is a major concern in wastewater treatment. The purpose of this study was the optimisation of emerging recalcitrant pollutant degradation using carbamazepine as a representative pollutant. Investigations of the carbamazepine degradation in wastewater was carried out by manipulating discharge current, air flow rate, and initial concentration to maximise removal efficiency and minimise energy consumption.METHODThe study utilised a three factor at two levels factorial design with randomised central runs. Discharge current, air flow rate, and initial concentration were the independent variables while to removal efficiency and minimise energy consumption were the response variables. ANOVA analysis was performed on the data.RESULTSDischarge current, air flow rate, and initial concentration significantly impacted the removal efficiency to different degrees. However, for energy consumption, only current and air flow rate were the significant variables. The highest removal efficiency obtained was 93% ± 4% for 10 and 40 mg/L initial carbamazepine concentration after 10 minutes of plasma treatment at a current of 0.45 A and no air flow rate.CONCLUSIONThe reactor demonstrated the capability to treat high cyclic organic chemical contaminant concentration in wastewater with possible applications in pre‐concentrated wastewater remediation. However, there is still room for reactor design optimisation. One key area of focus is reducing treatment cost, which may be achieved theoretically, pending further experimental investigation, by introducing an alternating current power supply which can reduce energy consumption by 50‐60%.