Process optimization of dielectric barrier discharge reactor for chloroform degradation using central composite design.

The increased detection of chloroform in wastewater and surface water bodies has become an environmental concern. However, conventional treatment methods such as biodegradation, incineration, and photocatalysis are challenging to scale up, inducing high operation costs and generating toxic byproducts. Hence, this study employs the Response surface methodology (RSM) to optimize chloroform degradation using a spray dielectric barrier discharge (DBD) reactor for the first time. The independent and interactive influence of the DBD parameters (power: 100–200 W, treatment time: 5–20 minutes, recirculating flow rate: 50–200 mL/M) and responses (chloroform degradation ratio (R), total organic carbon removal ratio (TOC)) were optimized using the Rotatable central composite design (RCCD), and a second-order polynomial equation was proposed to predict process efficiency. Results showed significantly predicted values (p < 0.05) and coefficient of determination of 0.96, and 0.93 for TOC and R, respectively, with treatment time and power having significant independent and interactive effects on the responses (TOC: p < 0.0001, R: p < 0.0001) concerning the variance analysis. Accordingly, the model yielded optimum recirculating flow rate, discharge power, and treatment time of 50 mL/min, 200 W, and 20 mins, respectively, which amounted to complete dechlorination of 300 mg/L chloroform, a 43% TOC removal ratio and an energy yield of 4.6 g/kW·h. In addition, the TOC removal ratio was enhanced with the increase in pH and conductivity of the solution. [ABSTRACT FROM AUTHOR]