| 紫外光降解对生物过滤塔去除氯苯性能的影响机制研究 |
| 摘要点击 2492 全文点击 1214 修订日期：2011-03-16 |
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| 中文关键词 挥发性有机物 氯苯 紫外光降解 生物过滤塔 机制 |
| 英文关键词 volatile organic compounds (VOCs) chlorobenzene UV photodegradation biofilter mechanism |
| 作者 | 单位 | E-mail | | 王灿 | 天津大学环境科学与工程学院,天津 300072
清华大学环境学院,环境模拟与污染控制国家重点联合实验室,北京 100084 | wangcan04@mails.tsinghua.edu | | 席劲瑛 | 清华大学环境学院,环境模拟与污染控制国家重点联合实验室,北京 100084 | xijinying@tsinghua.edu.cn | | 胡洪营 | 清华大学环境学院,环境模拟与污染控制国家重点联合实验室,北京 100084
清华大学深圳研究生院,深圳 518055 | hyhu@tsinghua.edu.cn | | 姚远 | 清华大学环境学院,环境模拟与污染控制国家重点联合实验室,北京 100084 | |
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| 中文摘要 |
| 紫外-生物过滤联合工艺中的紫外单元促进了后续生物过滤单元的氯苯去除性能.为了进一步揭示紫外光降解对生物过滤塔运行性能的影响机制,本研究系统分析了紫外光降解对生物过滤塔填料层pH、生物膜特性和填料层结构特性等方面的影响.结果表明,氯苯紫外光降解产物导致了生物过滤单元填料层pH的下降(从pH 6~8降至pH 4~7); 另外,紫外单元产生的臭氧降低了生物过滤单元生物膜厚度和生物膜的EPS含量,改善了生物膜的特性,提高了氯苯和营养物质在生物膜内的传质效率.同时,臭氧可以有效控制生物量过量积累,增加了填料层的比表面积(从784 m2·m-3增加至880 m2·m-3),优化了填料层的结构特性,提高了污染物的反应速率.上述各方面的综合作用最终促进了生物过滤单元的氯苯去除性能. |
| 英文摘要 |
| To provide insight into effects of UV pretreatment on a subsequent biofilters, the mechanisms of UV pretreatment on biofilter performance were further studied. Results showed that gaseous chlorobenzene UV photodegradation products resulted in a pH decrease from 6-8 to 4-7 in filter bed. Ozone produced by UV photodegradation changed the physical properties of biofilm by reducing biofilm thickness and oxidizing surface part of the extra-cellular polymer substance, which promoted the oxygen, nutrient and pollutant transfer to biofilm. The reduction of biofilm thickness further resulted in the improvement of filter bed's physical properties by providing a higher specific surface area of 880 m2·m-3 compared with the value of 784 m2·m-3 without UV pretreatment. |
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