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arXiv · 2407.01035

Off-site production of plasma-activated water for efficient sterilization: the crucial role of high-valence NOx and new chemical pathways

Zifeng Wang·Xiangyu Wang·Shenghang Xu·Renwu Zhou·Mingyan Zhang·Wanchun Li·Zizhu Zhang·Luge Wang·Jinkun Chen·Jishen Zhang·Li Guo·Dandan Pei·Dingxin Liu·Mingzhe Rong
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Abstract

Efficient sterilization of pathogens with cleaner methods is a critical concern for environmental disinfection and clinical anti-infective treatment. Plasma-activated water (PAW) is a promising alternative to chemical disinfectants and antibiotics for its strong sterilization ability and not inducing any acute toxicity, and only water and air are consumed during production. For more efficient water activation, plasma sources are commonly placed near or fully in contact with water as possible, but the risks of electrode corrosion and metal contamination of water threaten the safety and stability of PAW production. Herein, plasma-activated gas rich in high-valence NOx is generated by a hybrid plasma configuration and introduced into water for off-site PAW production. Plasma-generated O3 is found to dominate the gas-phase reactions for the formation of high-valence NOx. With the time-evolution of O3 concentration, gaseous NO3 radicals are produced behind N2O5 formation, but will be decomposed before N2O5 quenching. By decoupling the roles of gaseous NO3, N2O5, and O3 in the water activation, results show that short-lived aqueous species induced by gaseous NO3 radicals play the most crucial role in PAW sterilization, and the acidic environment induced by N2O5 is also essential. Moreover, SEM photographs and biomacromolecule leakage assays demonstrate that PAW disrupts the cell membranes of bacteria to achieve inactivation. In real-life applications, an integrated device for off-site PAW production with a yield of 2 L/h and a bactericidal efficiency of >99.9% is developed. The PAW of 50mL produced in 3 minutes using this device is more effective in disinfection than 0.5% NaClO and 3% H2O2 with the same bacterial contact time. This work provides new avenues for efficient PAW production and deepens insights into the fundamental processes that govern the reactive chemistry in PAW sterilization.

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Zifeng Wang, Xiangyu Wang, Shenghang Xu, Renwu Zhou, Mingyan Zhang, Wanchun Li, Zizhu Zhang, Luge Wang, Jinkun Chen, Jishen Zhang, Li Guo, Dandan Pei, Dingxin Liu, Mingzhe Rong. 2024-07-01. Off-site production of plasma-activated water for efficient sterilization: the crucial role of high-valence NOx and new chemical pathways. https://doi.org/10.1016/j.watres.2024.122541

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