Optimization of Cold Plasma Reactive Species and Efficacy of Virus Inactivation for Water Purification

Water is one of the most vital resources on Earth. Many developing countries do not have a robust infrastructure to treat and transport water, and the WHO estimates that more than 2 billion people are utilizing a contaminated drinking source. Nonthermal plasma water treatment could be a game changer for people living in areas without access to clean water, as it is well-suited for on-demand use and does not require a continuous supply of chemicals and filters. It is an effective advanced oxidation process capable of removing a wide array of contaminants, ranging from waterborne bacteria and viruses - to challenging industrial effluents like PFAS and common pharmaceuticals. This work aims to develop a simple, point-of-use, solar-powered plasma source that can be used for water treatment in developing areas lacking infrastructure. Here we report on progress in optimization of the plasma source which by design allows for selectivity control of the production of reactive oxygen species such as ozone and peroxide and nitrogen species such as nitrite and nitrate ions. We also quantify the efficacy of plasma at removing E.Coli and MS2 as surrogate pathogens in water. The overall goal of this work is to demonstrate that this technology can remove contaminants without adding them in the process.