响应曲面法优化水降膜等离子体装置生成臭氧及过氧化氢研究

Optimization of Ozone and Hydrogen Peroxide Generation in Water Falling Film Plasma Reactor Using Response Surface Methodology

中文关键词: 介质阻挡放电  水降膜等离子体装置  响应曲面  反应活性物质

英文关键词: Dielectric barrier discharge  Water falling film plasma reactor  Response surface methodology  Reactive active species

中文摘要:

      水降膜介质阻挡放电装置具有大的气相等离子体-液面接触面积和高的气-液传质效率，在降解液相污染物、合成等离子体活化水等领域具有广泛应用。水降膜等离子体装置的循环水量、通气量和输入电压是影响气相反应活性物质生成及其扩散进入水相的重要因素，直接影响液相污染物的降解效率或等离子体活化水的活性，因此，优化上述三个量的输入参数对于提升装置的运行效率具有重要意义。本文建立水降膜等离子体装置合成的O3和H2O2预测模型，通过Design-Expert设计响应面，分析了放电电压、液体循环流量、通气量对水降膜DBD系统产生O3和H2O2的影响。结果表明：O3和H2O2的生成浓度与放电电压均成正相关关系；通气量对液相臭氧浓度影响较大，对液相过氧化氢浓度影响很小；水循环量影响液相过氧化氢生成，但对水中O3浓度影响较小。根据模型预测，当放电电压、通气量和水循环量分别为25kV、0.5L/min 和1L/min时，水中O3和H2O2的浓度最高，分别为6.304mg/L和28.06mg/L；在此条件下，此时空气和一个循环中液膜在放电区停留时间分别为4.75s和0.14s，实验测得的O3和H2O2分别达到6.54 mg/L和30.48mg/L，模型预测值与实测值吻合较好。

英文摘要:

      The water falling-film dielectric barrier discharge reactor (WFDBDR) has a large gas phase plasma liquid surface contact area and high gas-liquid mass transfer efficiency, and is widely used in the degradation of aqueous pollutants, synthesis of plasma-activated water, etc. The circulating water rate, air aeration rate, and input voltage of the water falling film plasma reactor are important factors that affect the generation and diffusion of gas-phase reactive species into water, directly affecting the degradation efficiency of aqueous pollutants or the activity of plasma-activated water. Therefore, an optimization on the above-mentioned input parameters is of great significance for improving the operating efficiency of WFDBDR. In this article, a prediction model for the synthesized O3 and H2O2 in a WFDBDR was established, and the effect of discharge voltage, water circulation flow rate, and air aeration rate on the generation of O3 and H2O2 was analyzed through Design-Expert response surface methodology. The results show that the concentrations of O3 and H2O2 were positively correlated with the discharge voltage, and the air aeration rate had a significant impact on the concentration of aqueous ozone, but had little effect on the hydrogen peroxide concentration in water; moreover, the amount of water circulation affected the generation of hydrogen peroxide in water, but had little effect on the concentration of O3 in water. According to the prediction model, when the discharge voltage, air aeration rate, and water circulation rate are 25kV, 0.5L/min and 1L/min, respectively, the concentrations of O3 and H2O2 in water reach the highest values of 6.304mg/L and 28.06mg/L, respectively; Under these conditions, the residence times of air and liquid film in the discharge zone during one cycle were 4.75s and 0.14s, respectively, and the measured O3 and H2O2 concentrations reached 6.54 mg/L and 30.48 mg/L, respectively, which were in good agreement with the predicted values.