Wastewater Decontamination from Microorganisms by Electrospraying Corona Discharge

Abstract

A novel water treatment technique, based on a combination of electrospraying and pulsed corona discharge, has been used for bio-decontamination of wastewater. The electrospraying process has been found to increase the surface area of the treated wastewater, and hence increases the efficiency of the corona treatment process. The phase diagram of the discharge, which characterizes the discharge regimes, has been identified experimentally. The survival ratio of the mi-croorganisms has been investigated experimentally as a function of the applied voltage and the numbers of treatment runs using air and oxygen as working gases. Microorganism surface has been examined using scanning electron micro-scope (SEM), which enabled in understanding the decontamination mechanisms of the treated microorganism. A com-plete decontamination has been achieved after only one run for an applied voltage higher than 16 kV when the dis-charge system was operated in oxygen gas. Optical emission spectrum of the electrosprayed water confirmed the exis-tence of OH-radicals responsible for decontamination process.