喷淋-曝气吹脱组合工艺处理岩溶地下水CCl_4污染
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摘要
针对水体遭受挥发性有机污染事故,设计"喷淋-曝气吹脱"组合处理工艺,并建设岩溶地下水CCl_4污染治理示范工程,进行效能评估。运行结果表明:随着气水比的增大,水体中CCl_4的去除率逐步增大,尾气中CCl_4的质量浓度逐渐减小。在原水ρ(CCl_4)为11.30μg/L条件下,气水比为5.75时,出水可稳定达到GB 5749—2006《生活饮用水卫生标准》限值要求(2μg/L),此时尾气中ρ(CCl_4)为0.672 mg/m~3,远低于GB 31571—2015《石油化学工业污染物排放标准》规定的CCl_4排放限值(20 mg/m~3);CCl_4去除率与气水比的关系符合Logistic模型,当CCl_4出水ρ(CCl_4)为2μg/L时,气水比为5.48。罗茨风机压缩空气做功,曝气过程中,可能会导致岩溶地下水体发生脱碳酸作用,产生结垢;在保证出水达标的条件下,系统新增直接运行成本为0.058元/m~3。针对现有工艺在运行过程中存在的问题,分析原因,并提出了相应改进措施。
Spray-aeration combined process was used to treat volatile organic pollutants in water, and a demonstration project was built to treat carbon tetrachloride in karst underground water. Then the effectiveness of the demonstration project was evaluated. The results showed that, along with the growth of gas-water ratio, the removal rate of CCl_4 in the water increased gradually, and the mass concentration of CCl_4 decreased gradually in the off-gas. And the effluent quality could meet the limitation requirement of "Standards for Drinking Water Quality"(GB 5749—2006) at the initial concentration of 11.30 μg/L when the gas water ratio was 5.75. Under this condition, the mass concentration of carbon tetrachloride in the off-gas was 0.672 mg/m~3, much less than the limitation requirement of"Emission Standard of Pollutants for Petroleum Chemistry Industry"(GB 31571—2015). The relationship between the removal rate of CCl_4 and the gas-water ratio conformed to the Logistic model. When the gas water ratio was 5.48, the effluent quality of CCl_4 could get to 2 μg/L. The scaling phenomenon occurred because of the decarbonization caused by Roots blower compressing air. The new direct operating cost was 0.058 yuan/m~3 in the case that water quality met standards. Based on the shortage analysis of the technique, the reasons and the improving measures were presented in this paper.
Spray-aeration combined process was used to treat volatile organic pollutants in water, and a demonstration project was built to treat carbon tetrachloride in karst underground water. Then the effectiveness of the demonstration project was evaluated. The results showed that, along with the growth of gas-water ratio, the removal rate of CCl_4 in the water increased gradually, and the mass concentration of CCl_4 decreased gradually in the off-gas. And the effluent quality could meet the limitation requirement of "Standards for Drinking Water Quality"(GB 5749—2006) at the initial concentration of 11.30 μg/L when the gas water ratio was 5.75. Under this condition, the mass concentration of carbon tetrachloride in the off-gas was 0.672 mg/m~3, much less than the limitation requirement of"Emission Standard of Pollutants for Petroleum Chemistry Industry"(GB 31571—2015). The relationship between the removal rate of CCl_4 and the gas-water ratio conformed to the Logistic model. When the gas water ratio was 5.48, the effluent quality of CCl_4 could get to 2 μg/L. The scaling phenomenon occurred because of the decarbonization caused by Roots blower compressing air. The new direct operating cost was 0.058 yuan/m~3 in the case that water quality met standards. Based on the shortage analysis of the technique, the reasons and the improving measures were presented in this paper.
引文
[1] 刘永娟,韩宝平,王小英.地下水CCl4污染现状与治理技术研究进展[J].水资源保护,2005,21(2):5-8.
[2] 江岳,林健,王晓红.地层对CCl4迁移影响的实验研究[J].地球与环境,2011,39(4):592-596.
[3] Heron G, Lachance J, Baker R. Removal of PCE DNAPL from tight clays using in situ thermal desorption[J]. Groundwater Monitoring and Remediation, 2013,33(4):31-43.
[4] Kelley B, Koenigsber G S. Chemical oxidation treats soil and groundwater[J].Pollution Engineering, 2006,38(3):34-37.
[5] 刘志彬,方伟,陈志龙.饱和带地下水曝气修复技术研究进展[J].地球科学进展,2013,28(10):1154-1159.
[6] 范伟,杨悦锁,曹玉清,等. 石油类污染地下水土环境的曝气修复实验研究[J].节水灌溉,2010(5):5-8.
[7] 张伟. 曝气吹脱去除水源水中挥发性有机物的应急处理技术研究[D].北京:清华大学,2011:16.
[8] 汪艳.曝气吹脱技术去除水源水氯苯的初步研究[D].黑龙江:哈尔滨工业大学,2011.
[9] 黄豪,马斐,马玉华. Logistic曲线模型在区域经济长期预测中的应用[J].武汉理工大学学报(信息与管理工程),2011,33(1):94-97.
[10] 张新华.江苏省徐州市地下水资源调查评价报告[R].江苏:江苏省水文地质工程地质勘察院,2002:50-54.
[11] 刘兆昌,李广贺,朱琨.供水水文地质[M].4版. 北京:中国建筑工业出版社,2011:76.
[2] 江岳,林健,王晓红.地层对CCl4迁移影响的实验研究[J].地球与环境,2011,39(4):592-596.
[3] Heron G, Lachance J, Baker R. Removal of PCE DNAPL from tight clays using in situ thermal desorption[J]. Groundwater Monitoring and Remediation, 2013,33(4):31-43.
[4] Kelley B, Koenigsber G S. Chemical oxidation treats soil and groundwater[J].Pollution Engineering, 2006,38(3):34-37.
[5] 刘志彬,方伟,陈志龙.饱和带地下水曝气修复技术研究进展[J].地球科学进展,2013,28(10):1154-1159.
[6] 范伟,杨悦锁,曹玉清,等. 石油类污染地下水土环境的曝气修复实验研究[J].节水灌溉,2010(5):5-8.
[7] 张伟. 曝气吹脱去除水源水中挥发性有机物的应急处理技术研究[D].北京:清华大学,2011:16.
[8] 汪艳.曝气吹脱技术去除水源水氯苯的初步研究[D].黑龙江:哈尔滨工业大学,2011.
[9] 黄豪,马斐,马玉华. Logistic曲线模型在区域经济长期预测中的应用[J].武汉理工大学学报(信息与管理工程),2011,33(1):94-97.
[10] 张新华.江苏省徐州市地下水资源调查评价报告[R].江苏:江苏省水文地质工程地质勘察院,2002:50-54.
[11] 刘兆昌,李广贺,朱琨.供水水文地质[M].4版. 北京:中国建筑工业出版社,2011:76.