不同脉冲参数下等离子体活化水活性氮特性

Reactive Nitrogen Species Characteristic of Plasma-activated Water Under Different Pulsed Parameters

等离子活化水能够产生丰富的活性粒子,在农业生产、果蔬消毒、生物医疗等领域有着广泛的应用。为此设计了一种基于微气泡技术的活化水产生装置,并研究了脉冲参数(上升沿、脉冲宽度)对活化水中活性氮特性的影响规律。测量了活化水中NO_(2)-和NO_(3)-浓度及pH值,计算了不同脉冲参数下消耗单位能量所产生活性粒子的通量,并讨论了微气泡破裂对活性氮物质的影响机制。结果表明,采用液相微气泡放电产生等离子体的方式能有效提升活化水活性物质浓度。上升沿较快、宽度较窄的脉冲有利于活性物质的产生。百纳秒量级脉冲激励的活性氮产量最高,其中NO_(3)-浓度为36×10^(-2)mmol/L,NO_(2)-浓度为18×10^(-2)mmol/L。不同脉冲参数下对应的能耗最高时为4.54 W,最低时为1.99 W。该研究为等离子体活化水装置的设计和活性粒子浓度的提升方法提供了依据。

Plasma-activated water has been widely used in agricultural production,fruit and vegetable disinfection,biological medicine and other fields owning to the production of reactive species.In this work,an activated-water generation device based on microbubble structure was designed.Effects of different electrical pulsed parameters(including rise time and pulse width)on the activated nitrogen characteristics in activated water were investigated.The concentrations of NO_(2)-and NO_(3)-,pH values,energy consumption of different electrical pulsed parameters in activated water were measured and calculated.The influence mechanism of microbubble bursting on active nitrogen was discussed.The results show that the plasma generated by liquid phase microbubble discharge efficiently increases the concentration of active substances in activated water.Pulses with fast rising edge and narrow width is beneficial to the generation of reactive species.In the experiment,the highest yield of reactive nitrogen species appears under the activation of hundred-nanosecond-level electrical pulses,in which the concentration of NO_(3)-is 36×10^(-2)mmol/L and the concentration of NO_(2)-is 7.9×10^(-2)mmol/L.The energy consumptions with different electrical pulse parameters are 4.54 W at the highest and 1.99 W at the lowest.This study provides a basis for the design of plasma-activated water device and the method of increasing the concentration of reactive species.