The sequestration of Cr(VI) by zero valent iron under a non-uniform magnetic field: An interfacial dynamic reaction
The sequestration of Cr(VI) by zero valent iron under a non-uniform magnetic field: An interfacial dynamic reaction
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非均匀磁场下零价铁对 Cr(VI) 的螯合：界面动态反应
DOI：
10.1016/j.chemosphere.2020.126057
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发表时间：
2020
期刊：
影响因子：
8.8
通讯作者：
Xu Chunhua
中科院分区：
文献类型：
--
作者：
Zhang Yue;Gao Xuyan;Xu Chunhua
焦化厂土壤中的多环芳烃（PAHs）和苯、甲苯、二甲苯、乙苯（BTEX）是典型的指示化合物。一般来说，多环芳烃富集在表层土壤中。苯系物具有较高的水溶解度和较低的有机碳-水分配系数（Koc），比多环芳烃分布更深。然而，目前的模型采用预测使用单一的化合物来模拟迁移的苯系物在受污染的焦化场地。这些模型没有考虑土壤上层的影响，而土壤上层是多环芳烃富集的地方。本研究试图通过建立控制土柱试验来填补这一空白。一个柱填充原状土壤（柱#1）和其他与PAH污染的土壤（柱#2），以模拟理论和实际的表层土壤层，分别。结果表明，在柱#2中，顶部空间的甲苯气体浓度和达到稳态所需的时间显著大于柱#1中的那些。高通量测序结果表明，两个土柱中的微生物群落结构存在较大差异，而一些高效降解甲苯的菌群在2号土柱中明显出现。这表明土壤上层富集多环芳烃有利于甲苯蒸气的降解。将这一发现应用于甲苯的人体健康暴露评估表明，考虑到受污染焦化场地的意外衰减，潜在暴露水平应从目前的预测水平降低。
In the soil of contaminated coking sites, polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and xylene (BTEX) are typical indicator compounds. Generally, PAHs are enriched in the topsoil layer. BTEX, with higher water solubilities and lower organic carbon-water partitioning coefficients (Koc), are distributed deeper than PAHs. However, current models have employed predictions using single compounds to mimic the migration of BTEX at contaminated coking sites. Such models have not considered the influence of the upper soil layer, where PAHs are enriched. An attempt to fill this gap was made by setting up a control soil column experiment in this study. One column was filled with undisturbed soil (column #1) and the other with PAH-contaminated soil (column #2) to simulate the theoretical and actual surface soil layers, respectively. The results showed that in column #2, the toluene gas concentration of the headspace and time required to reach steady state were notably greater than those in column #1. High-throughput sequencing revealed that there were large microbial community structure differences between the two soil columns throughout the experiment, while some genera that degrade toluene with high efficiency emerged noteworthily in column #2. This implied that the upper soil layer enriched with PAHs was conducive to the degradation of toluene vapor. Applying this finding to human health exposure assessment of toluene suggests that the potential exposure level should be reduced from the current predicted level given the unanticipated attenuation at contaminated coking sites.