摘要
利用钛基二氧化铅电极(Ti/PbO_2)作为电催化活性阳极,通过电化学氧化技术对苯醌进行降解矿化,考察常见共存无机盐对苯醌废水降解效率的影响。结果表明,NaCl存在下苯醌废水溶液的COD去除率相比硝酸盐提高了62%,相比硫酸盐提高了45%,NaCl能够显著增强电氧化去除苯醌的电流效率。苯醌的降解对氯离子非常敏感,存在少量的氯离子即可以引起氧化效率明显增加。氯离子浓度越高,苯醌模拟废水的COD去除率越高;但当氯离子浓度高于0.3mol·L^(-1)时,COD去除率反而有所下降。pH为8的弱碱性环境更有利于含氯离子苯醌废水的电氧化降解反应。提高电流密度可增大COD去除率;但升高温度会降低COD去除率。在pH为8、NaCl浓度为0.3 mol·L^(-1)、电流密度为10mA·cm^(-2)、温度为20℃的条件下,初始浓度为100 mg·L^(-1)的苯醌经3 h电化学氧化降解后COD去除率可达80.9%。通过高效液相色谱对电氧化降解苯醌的中间产物进行分析,发现氯离子存在下苯醌的降解速度显著提高,中间产物顺丁烯二酸的生成速度更快,这说明由氯离子生成的强氧化剂对苯醌具有极强的开环能力。
In this study, an electrochemical oxidation technique with titanium-based lead dioxide(Ti/PbO2) as an active anode was used to degrade and mineralize benzoquinone. The effect of common inorganic salts on the degradation efficiency of benzoquinone wastewater was investigated. The results showed that in the presence of NaCl, the removal rate of COD in benzoquinone wastewater was 62% higher than that of nitrate and 45% higher than that of sulfate. NaCl could significantly enhance the current efficiency of benzoquinone mineralization by this electrochemical oxidation technique. The electro-degradation of benzoquinone was very sensitive to chloride ions, and a small amount of chloride ions could lead to a significant increase in degradation efficiency. The higher the chloride concentration, the higher the COD removal rate for the simulated wastewater with benzoquinone. However, the COD removal rate decreased when the chloride concentration was higher than 0.3 mol·L-1. The weak alkaline environment with pH = 8 was more favorable to the electrochemical oxidation and degradation in benzoquinone wastewater containing chloride ions. COD removal rate increased with the increase of the current density, while it decreased with increase of temperature. At pH=8, 0.3 mol· L-1 NaCl, current density of 10 mA·cm-2 and 20 ℃, the COD removal rate for benzoquinone wastewater with initial concentration of100 mg·L-1 could reach 80.9% after 3 h electro-oxidation degradation. High performance liquid chromatography(HPLC) was used to analyze the intermediate products of electro-oxidation degradation of benzoquinone. It was found that the benzoquinone degradation rate increased significantly in the presence of chloride ion, and the intermediate product of maleic acid was fast produced, which implied that the strong oxidant produced by chlorine ions has strong ability to open the aromatic ring of benzoquinone.
作者
薛娟琴
张立华
于丽花
XUE Juanqin;ZHANG Lihua;YU Lihua(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2019年第3期607-615,共9页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51874227)
陕西省自然科学基金资助项目(2017ZDJC-25)
陕西省自然科学基础研究计划项目(2018JM5139)
陕西省教育厅产业化培育项目(18JC016)
关键词
电化学氧化
含盐苯醌模拟废水
含盐废水处理
electrochemical oxidation
simulated wastewater with salinity and benzoquinone
salinity wastewater treatment
