Treatment of Escherichia coli contaminated water with different pulse-powered NTP configurations and analysis for post treatment efficacy

Abstract

A cost-effective and energy efficient method for water sterilization is a challenging demand in the present scenario where scarcity of pure water is rising. Non-Thermal Plasma (NTP) finds promising applications in environmental processes and has advantages over conventional water treatment methods. Escherichia coli contaminated water treatment using multiple pin plasma reactor and atmospheric pressure plasma jet reactor was undertaken in this work. High voltage pulsed power was used for generating non-thermal plasma in these reactors and various configurations were tested for treating the contaminated water. The most feasible configuration among these was identified from the treatment efficiency and survival rate plots of E. coli colonies. It was observed that with an exposure of 15 min NTP, 100 percent bacterial removal was achieved using plasma jet reactor configuration. The presence of bacteria after NTP-treated time was also checked and confirmed for complete removal of bacteria. An optimum time of 15 min plasma exposure for 100 ml was found to be effective for complete removal of microorganisms and the sterility was maintained up to 60 min after the treatment. Non-thermal plasma-based treatment of bacteria-contaminated water is found to be promising and could be considered for scale-up and analysis.