低温等离子体降解偏二甲肼废水研究

该文研究了悬浮电极介质阻挡放电装置(FE-DBD)产生的低温等离子体对偏二甲肼废水的降 解效果，并对处理条件进行优化。首先，对比了低温等离子体装置、氙灯和紫外灯降解偏二甲肼废水的效果；然后，考察了低温等离子体装置的放电间隙、初始溶液 pH、工作时间和氢氧化钠加投量对偏 二甲肼降解的影响；最后，探究了低温等离子体对偏二甲肼废水 pH 值的影响。实验结果表明，不加入其他试剂的情况下，低温等离子体装置降解偏二甲肼效果好于氙灯及紫外灯；装置放电间隙从 4 mm缩短至 2 mm，偏二甲肼降解率增加 47.2%。随着等离子体处理时间的增加，偏二甲肼的含量降低，处理 20 min 即可降解 82.1% 偏二甲肼。同时，低温等离子体处理会引起偏二甲肼废水 pH 值下降，处理10 min 后废水 pH 从 10 下降至 6.9。废水初始 pH 在 2～10 时，偏二甲肼降解率随废水 pH 值的升高而增大 ：与 pH＝2 相比，初始 pH＝10 时偏二甲肼降解率增加 65.9%。低温等离子体处理 10 min 后，往废水中加入氢氧化钠溶液至终浓度为 1 mg/mL，再继续处理 10 min，可将偏二甲肼降解率提高至 95%。

A Study on Degradation of Unsym-Dimethylhydrazine Waste Liquid by Low Temperature Plasma

In this paper, the degradation of unsym-dimethylhydrazine wastewater with low atmospheric plasma generated by floating-electrode dielectric barrier discharge was studied, and the treatment conditions were optimized. Firstly, the degradation effects of low atmospheric plasma equipment, xenon lamp and ultraviolet lamp were compared. Secondly, the influence of discharge gap, initial solution pH, treatment time, addition of sodium hydroxide solution were also studied. Meanwhile, the effect of low temperature plasma on the pH value of unsym-dimethylhydrazine wastewater was also investigated. Without the addition of other reagents, the degradation of unsym-dimethylhydrazine with low temperature plasma was better than xenon lamp and ultraviolet lamp. When the discharge gap was shortened from 4 mm to 2 mm, the degradation rate of unsymdimethylhydrazine was increased by 47.2%. With the increase of plasma treatment time, the content of unsymdimethylhydrazine decreased, and 82.1% of unsym-dimethylhydrazine could be degraded after treatment for 20 minutes. The pH value of the unsym-dimethylhydrazine wastewater decreased from 10 to 6.9 after 10 min of treatment. While, the degradation rate of unsym-dimethylhydrazine increased by 65.9% with the initial pH value increased from 2 to 10. After 10 min of low temperature plasma treatment, sodium hydroxide solution was added to the wastewater with a concentration of 1 mg/mL, and the degradation rate of unsym-dimethylhydrazine reached 95% after another 10 min treatment.