研究报告
商莹,姜楠,孙浩洋,刘政妍,李娜,彭邦发,李杰,吴彦.脉冲放电等离子体同时处理地下水中Cr(VI)和阿特拉津的研究[J].环境科学学报,2022,42(7):371-379
脉冲放电等离子体同时处理地下水中Cr(VI)和阿特拉津的研究
- Simultaneous treatment of Cr (VI) and atrazine in groundwater by pulsed discharge plasma
- 基金项目:国家自然科学基金(No.21876070)
- 彭邦发
- 大连理工大学电气工程学院,大连 116024
- 摘要:常规地下水修复技术如物理法、化学法和生物法难以同时降解地下水中重金属-有机物复合污染.本文提出多针-板脉冲放电等离子体 同时降解地下水中重金属和有机物复合污染的方法.以Cr(VI)和阿特拉津为目标污染物,研究复合污染中Cr(VI)和阿特拉津浓度、放电电压、溶液初始pH值和地下水中存在的主要离子对Cr(VI)和阿特拉津降解效果的影响,并探究放电过程生成的活性物质对复合污染中Cr(VI)和 阿特拉津降解的作用效应.结果表明,相对单一污染物,复合污染物中Cr(VI)或阿特拉津的存在能够消耗放电过程产生的·H和·OH,阻碍其复合,Cr(VI)和阿特拉津在降解过程中产生协同效应.电压为13 kV时,单独处理10 mg?L-1的Cr(VI)和阿特拉津的降解效率分别为34.0%和51.5%,而复合污染中Cr(VI)和阿特拉津的初始浓度均为10 mg?L-1时,降解效率分别提高到45.0%和64.1%.放电电压增加,复合污染中Cr(VI)和阿特拉津的降解效率提高,但其能量效率呈下降趋势.增加溶液初始pH值,阿特拉津的降解效率减小,而Cr(VI)的降解效率呈现先减小 后增加的趋势,pH为9.2时Cr(VI)和阿特拉津的降解效率最佳.地下水中存在的7种离子(Na+、K+、Ca2+、Mg2+、Cl-、SO42-、HCO3-)除HCO3-抑制 阿特拉津降解外,其它离子对降解无明显影响.O3、H2O2生成量测定和自由基清除实验表明,·OH和·O2-对阿特拉津的氧化起关键作用,H2O2和·H对Cr(VI)的还原起作用.
- Abstract:Conventional groundwater remediation technologies such as physical method, chemical method and biological method are difficult to simultaneously degrade combined pollution caused by organic pollutant and heavy metals in groundwater. In this paper, a multi-needle to plate gas-liquid pulsed discharge plasma was proposed to simultaneously remove heavy metals and organic pollutants. Cr(VI) and atrazine were selected as targeted pollutants. The effects of Cr(VI) and atrazine concentrations, discharge voltage, initial pH of solution and ions types in groundwater on the degradation of Cr(VI) and atrazine were also investigated. And the role of active substances generated in the discharge process in the degradation of Cr(VI) and atrazine was discussed. The results showed that compared with the removal of single pollutant, the presence of Cr(VI) or atrazine in the combined pollution could consume ·H and ·OH generated by the discharge process, which could hinder its recombination and results in a synergistic degradation of Cr(VI) and atrazine in combined pollution.When the voltage was 13 kV, the degradation efficiencies of Cr(VI) and atrazine in single pollution were 34.0% and 51.5%, respectively, while those increased to 45.0% and 64.1% in combined pollution when the initial concentrations of Cr(VI) and atrazine were 10 mg?L-1. The degradation efficiency of Cr(VI) and atrazine in combined pollution increased with discharge voltage, however, the energy efficiency followed an opposite trend. As the initial pH value increased, the degradation efficiency of atrazine decreased, while the degradation efficiency of Cr(VI) first decreased and then increased. The best degradation efficiencies of Cr(VI) and atrazine were obtained at pH of 9.2. The ions in groundwater including Na+, K+, Ca2+, Mg2+, Cl-, SO42- have little effect in Cr(VI) and atrazine degradation, while only HCO3- inhibited atrazine degradation. The identification result of O3, H2O2 and free radical scavenging experiments indicated that ·OH, ·O2- played a key role in the degradation of atrazine, and H2O2, ·H participated in the reduction of Cr(VI).