Division of Environmental Physics - User: student
Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava

Plasma Activated Water (PAW): Sustainable Technology for Wastewater Treatment. Selective production of Reactive Oxygen and Nitro

Saeed Kooshki, Pankaj Pareek, Robin Mentheour, Mario Janda, Zdenko Machala
XXXV ICPIG, 17, July 9-14,, p. 28 (2023)

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Abstract:

The global water crisis is a significant challenge posed by the rapidly growing world population. By 2050, the UN predicts that nearly six billion people will face water scarcity, and demand for water is expected to surge over the next two decades, particularly in agriculture, which accounts for the largest demand sector, projected to increase by 60% by 2025 [1]. One potential and eco-friendly solution to address water contamination and excessive use in agriculture is the use of Non-Thermal Plasma (NTP) treatment of wastewater. NTP treatment can effectively decontaminate wastewater by enriching it with Reactive Oxygen and Nitrogen Species (RONS), hence producing Plasma-Activated Water (PAW). Such NTP-treated PAW can be reused in agriculture to enhance plant growth and seed germination [2].
In this study, we investigated the effectiveness of NTP as a sustainable technology to treat Staphylococcus epidermidis bacteria-contaminated water and to enhance barley seed germination in vitro using PAW produced from the plasma treatment of wastewater.
Our results showed that the use of PAW produced from plasma wastewater treatment improved barley seed germination by over 20% compared to tap water (Figure 1). We also investigated the chemical and bactericidal effects induced by NTP on the bacteria suspensions. We found that the inactivation of bacteria suspensions was dependent on pH and Oxidation-Reduction Potential (ORP), which correlated with the chemical RONS changes induced in the PAW. We used Response Surface Methodology (RSM) to determine the optimum plasma treatment time as the main parameter in the experiments to minimize electric power consumption for bulk water treatment. Our findings showed that plasma treatment after the optimum treatment time can reduce Staphylococcus bacteria in water by up to 7 logs (Figure 2). Furthermore, we observed a significant decrease in hydrogen peroxide and nitrite concentrations, as well as pH, after reaching the optimum plasma treatment time.
Overall, our study demonstrates that NTP treatment of wastewater represents an efficient approach for the water recovery for sustainable agriculture.