摘要
以某场地1,1,1-三氯乙烷(TCA)和1,4-二口恶烷(1,4-D)复合污染地下水为研究对象,探讨了超声(US)与氧化剂[S2O2-8(PS)和H2O2]协同降解目标污染物的效能、影响因素和急性毒性抑制效应。结果表明,室温25℃、初始p H8.2、氧化剂/1,4-D摩尔比200∶1、超声频率400 k Hz、强度2.67 W·cm-2、功率100 W时,复合污染地下水经4种体系处理4 h,其中"US+PS+H2O2"耦合体系的降解效果最佳,TCA可完全去除,1,4-D去除率为33%。基于两种污染物的去除效果,PS、H2O2投量和反应温度对耦合体系污染物去除影响较大,较佳氧化剂投量为:PS、H2O2与1,4-D摩尔比分别为1000∶1和200∶1。按该投量且控温时TCA和1,4-D分别经6 h和10 h后完全去除,其急性毒性抑制效应分别降低98.81%和99.87%;非恒温时温度逐渐增至60℃,目标污染物去除速度明显加快,相比恒温时耗时分别缩短1 h和3 h。试验证明,超声协同降解工艺是一种有应用前景的修复TCA和1,4-D复合污染地下水的有效方法。
In China there is little information available about the degradation of 1,1,1-trichloroethane(TCA)and 1,4-dioxane(1,4-D)in groundwater. Here the efficiencies, influencing factors and acute toxicity effects of TCS and 1,4-D degradation in ultrasonics(US)and/or oxidants[persulfate(PS)and H2O2] systems were examined. Results showed that the'US+PS+H2O2'system exhibited the best treatment performance, in which 100% of TCA and 33% of 1,4-D were degraded within 4 h at 25 ℃, initial p H of 8.2, oxidant/1,4-D molar ratio of 200∶1,ultrasonic frequency of 400 k Hz, ultrasonic intensity of 2.67 W·cm-2and power of 100 W. Oxidants(PS and H2O2)and reaction temperature had important impacts on the removal of TCA and 1,4-D. The optimum oxidant doses were:H2O2/1,4-D=200∶1, and PS/1,4-D=1000∶1. At a constant temperature of 25 ℃, TCA and 1,4-D were completely removed after 6 h and 10 h, and the acute toxicities of treated groundwater were decreased by 98.81% and 99.87%, respectively. Rising temperature gradually to 60 ℃ enhanced the degradation rates of target pollutants, and shortened degradation time by 1 h and 3 h, respectively. These results show that ultrasonics plus oxidants is a promising method for remediating concurrently contaminated groundwater with TCA and 1,4-D.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2015年第11期2183-2189,共7页
Journal of Agro-Environment Science
基金
国家自然科学基金(41303095)
上海市自然科学基金(13ZR1435200
12ZR1426500)
上海市人才发展资金(201320)
上海市环保局重大科研项目(沪环科2014-07)
上海市环保局青年基金(H214305)
上海市环科院青创基金(CX201304)