State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China.
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China.
J Environ Sci (China). 2016 Sep;47:143-152. doi: 10.1016/j.jes.2015.12.032. Epub 2016 Mar 31.
We explored the feasibility and removal mechanism of removing 2-chlorobiphenyl (2-ClBP) from soil-water system using granular activated carbon (GAC) impregnated with nanoscale zerovalent iron (reactive activated carbon or RAC). The RAC samples were successfully synthesized by the liquid precipitation method. The mesoporous GAC based RAC with low iron content (1.32%) exhibited higher 2-ClBP removal efficiency (54.6%) in the water phase. The result of Langmuir-Hinshelwood kinetic model implied that the different molecular structures between 2-ClBP and trichloroethylene (TCE) resulted in more difference in dechlorination reaction rates on RAC than adsorption capacities. Compared to removing 2-ClBP in the water phase, RAC removed the 2-ClBP more slowly in the soil phase due to the significant external mass transfer resistance. However, in the soil phase, a better removal capacity of RAC was observed than its base GAC because the chemical dechlorination played a more important role in total removal process for 2-ClBP. This important result verified the effectiveness of RAC for removing 2-ClBP in the soil phase. Although reducing the total RAC removal rate of 2-ClBP, soil organic matter (SOM), especially the soft carbon, also served as an electron transfer medium to promote the dechlorination of 2-ClBP in the long term.
我们探索了使用负载纳米零价铁的颗粒活性炭（反应性活性炭或 RAC）从水土系统中去除 2-氯联苯（2-ClBP）的可行性及其去除机制。通过液相沉淀法成功合成了 RAC 样品。低铁含量（1.32%）的介孔 GAC 基 RAC 在水相中表现出更高的 2-ClBP 去除效率（54.6%）。Langmuir-Hinshelwood 动力学模型的结果表明，2-ClBP 和三氯乙烯（TCE）之间的不同分子结构导致 RAC 上的脱氯反应速率比吸附容量有更多差异。与在水相中去除 2-ClBP 相比，由于显著的外部传质阻力，RAC 在土壤相中去除 2-ClBP 的速度较慢。然而，在土壤相中，RAC 表现出比其基础 GAC 更好的去除能力，因为对于 2-ClBP 的总去除过程，化学脱氯起着更重要的作用。这一重要结果验证了 RAC 在土壤相中去除 2-ClBP 的有效性。尽管降低了 2-ClBP 的总 RAC 去除率，但土壤有机质（SOM），特别是软碳，也作为电子转移介质，从长期来看促进了 2-ClBP 的脱氯。
