Parameters Influencing the Plasma-Mediated Inactivation of Microorganisms and Viruses in Wastewater

Abstract

Pathogenic microorganisms and viruses in water pose an environmental risk demanding for effective remediation tools like physical plasma. However, parameters influencing its efficiency are mostly descriptive. Plasma treatment of raw wastewater resulted in a reduced microbial count by up to 2.8-log10. This wastewater was used to determine, e.g., the chemical oxygen demand (COD), pH-value, nitrite and nitrate. Particularly, the COD-influence on microbial inactivation was analyzed by synthetic wastewater (organism: antibiotic-resistant Escherichia coli). A low COD resulted in a high bacterial inactivation (up to 6.1-log10). Preliminary data revealed similar effects for virus-containing solutions (Phi6 and MS2 bacteriophages as surrogates for SARS-CoV-2). This information is needed to estimate the antimicrobial and antiviral efficacy of plasma for the development of effective remediation processes.