Wastewater treatment by dielectric barrier discharge plasma

Abstract

This paper presents the influence of atmospheric non-thermal plasma on household wastewater by using dielectric barrier discharge (DBD) plasma generator. The model was designed in a vertical coaxial tube shape. The high voltage was supplied from high frequency AC power supply to the model for plasma generation at 0 (control group), 10, and 15 kV. Wastewater was released from the top of glass tube passing through DBD corona discharges that was generated between the needle tips and the glass tube, flowed down to the storage tank, and pumped to the top of the model again. The treatment process was operated for 30 minutes with the flow rate of water at 2 min/L. From the experimental results, it shows that all plasma treatment conditions could improve the wastewater quality. The best results were found at 15 kV plasma treated wastewater; the alkalinity, dissolved oxygen (DO), and conductivity were increased from the control group for 10.48%, 10.09%, and 17.79%, respectively. In addition, biochemical oxygen demands (BOD), and chemical oxygen demand (COD) were decreased from the control group for 7.5 times and 37.5%, respectively. An offensive odor of wastewater could be also improved. © 2019 Published under licence by IOP Publishing Ltd.