An anaerobic two-layer permeable reactive biobarrier for the remediation of nitrate-contaminated groundwater.
An anaerobic two-layer permeable reactive biobarrier for the remediation of nitrate-contaminated groundwater.
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DOI：
10.1016/j.watres.2013.06.028
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发表时间：
2013-10
期刊：
影响因子：
12.8
通讯作者：
Shejiang Liu;Zhijiang Zhao;Jie Li;Juan Wang;Yun Qi
中科院分区：
文献类型：
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作者：
Shejiang Liu;Zhijiang Zhao;Jie Li;Juan Wang;Yun Qi
本文首先设计了由氧气捕获层和生物降解层组成的厌氧双层渗透性反应生物屏障系统，用于评估硝酸盐污染地下水的修复效果。第一层填充颗粒状捕氧材料，用于捕获地下水中的溶解氧（DO），为微生物反硝化创造厌氧条件。此外，还可以为第二层固定化反硝化细菌的正常代谢提供碳、磷等营养。第二层使用粒状活性炭作为微生物载体，能够生物降解进入屏障系统的硝酸盐。通过批量实验研究了DO对微生物反硝化作用的影响、零价铁（ZVI）粉末的捕氧性能以及所制备的用于刺激反硝化细菌生长的捕氧材料的特性。然后使用两个连续上流式不锈钢柱进行实验室规模的实验，以评估该设计系统的可行性。第一个柱填充由ZVI粉末、柠檬酸钠以及其他无机盐等制备的颗粒状捕氧材料。第二个柱填充活性炭固定化反硝化微生物群落。将 DO 含量为 6 mg/L 的模拟硝酸盐污染地下水（40 mg NO3-N/L，pH 7.0）以 235 mL/d 的流速泵入该系统。对第二根柱的样品进行了硝酸盐及其主要降解副产物的分析。结果表明，硝酸盐可以去除94%以上，其代谢中间体亚硝酸盐也可以在这个被动系统中进一步生物降解。为了评估其现场应用的性能，有必要进行进一步的研究。
In this paper, an anaerobic two-layer permeable reactive biobarrier system consisting of an oxygen-capturing layer followed by a biodegradation layer was designed firstly for evaluating the remediation effectiveness of nitrate-contaminated groundwater. The first layer filling with granular oxygen-capturing materials is used to capture dissolved oxygen (DO) in groundwater in order to create an anaerobic condition for the microbial denitrification. Furthermore, it can also provide nutrition, such as carbon and phosphorus, for the normal metabolism of immobilized denitrifying bacteria filled in the second layer. The second layer using granular activated carbon as microbial carrier is able to biodegrade nitrate entering the barrier system. Batch experiments were conducted to identify the effect of DO on microbial denitrification, oxygen-capturing performance of zero valent iron (ZVI) powder and the characteristics of the prepared oxygen-capturing materials used to stimulate growth of denitrifying bacteria. A laboratory-scale experiment using two continuous upflow stainless-steel columns was then performed to evaluate the feasibility of this designed system. The first column was filled with granular oxygen-capturing materials prepared by ZVI powder, sodium citrate as well as other inorganic salts, etc. The second column was filled with activated carbon immobilizing denitrifying microbial consortium. Simulated nitrate-contaminated groundwater (40 mg NO3–N/L, pH 7.0) with 6 mg/L of DO content was pumped into this system at a flow rate of 235 mL/d. Samples from the second column were analyzed for nitrate and its major degradation byproduct. Results showed that nitrate could be removed more than 94%, and its metabolic intermediate, nitrite, could also be biodegraded further in this passive system. Further study is necessary in order to evaluate performance of its field application.