The chemistry, antimicrobial efficacy and energy consumption of plasma-activated water (PAW) was optimized by altering the discharge frequency, ground-electrode configuration, gas flow rate and initial water conductivity for two reactor configurations, i.e., air pin-to-liquid discharge and air plasma-bubble discharge in water. The ratio of NO₂⁻ and NO₃⁻ formation was altered to optimise the antimicrobial effects of PAW, tested against two Gram-negative bacteria. An initial solution conductivity of 0.2 S·m⁻¹ and 2000-Hz discharge frequency with the ground electrode positioned inside the pin reactor showed the highest antimicrobial effect resulting in a 3.99 ± 0.13-log₁₀ reduction within 300 s against Escherichia coli and 5.90 ± 0.24-log₁₀ reduction within 240 s for Salmonella Typhimurium. An excellent energy efficiency of reactive oxygen and nitrogen species (RONS) generation of 10.1 ± 0.1 g·kW⁻¹·h⁻¹ was achieved.

Industrial relevance

Plasma-activated water (PAW) is deemed as an eco-friendly alternative to chemical disinfection because its bactericidal activity is temporary. Optimizing the design and operation of PAW reactors to achieve high inactivation rates of more than 5-log₁₀ reductions, as demonstrated in this work, will support the industrial application of this technology and the scaleup at industrial level.

中文翻译：

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通过两种反应器设计配置优化用于食品消毒的等离子活化水的功效

通过改变两种反应器配置的放电频率、接地电极配置、气体流速和初始水电导率，即气针到液体放电，优化了等离子体活化水 (PAW) 的化学性质、抗菌功效和能耗和空气中的等离子气泡放电。NO ₂ ^-和NO ₃ ^-形成的比率被改变以优化PAW的抗微生物作用，针对两种革兰氏阴性细菌进行测试。0.2 S·m ^-1的初始溶液电导率和 2000-Hz 放电频率以及位于 pin 反应器内部的接地电极显示出最高的抗菌效果，导致 3.99 ± 0.13-log ₁₀对大肠杆菌在 300 秒内减少，对鼠伤寒沙门氏菌在 240 秒内减少5.90 ± 0.24-log ₁₀。实现了 10.1 ± 0.1 g·kW ^-1 ·h ^-1的活性氧和氮物质 (RONS) 生成的出色能量效率。

工业相关性

等离子活化水 (PAW) 被认为是化学消毒的环保替代品，因为它的杀菌活性是暂时的。如本工作所示，优化 PAW 反应器的设计和运行以实现超过 5-log _{10 的}高灭活率，将支持该技术的工业应用和工业级规模化。