Department of Civil Engineering, The University of Texas at Arlington, 416 Yates Street, Arlington, TX 76019-0308, USA; Environmental and Earth Sciences Program, The University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019-0049, USA.
Environmental and Earth Sciences Program, The University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019-0049, USA.
J Hazard Mater. 2015 Apr 28;287:118-25. doi: 10.1016/j.jhazmat.2015.01.034. Epub 2015 Jan 13.
Sediment (WHS) in Waukegan Harbor, Illinois, heavily contaminated and aged with polychlorinated biphenyls (PCBs), was treated with reactive activated carbon (RAC) impregnated with palladized iron nanoparticles. Lab test proceeded in a direct mixing configuration of RAC and WHS. A compartment configuration, where RAC was physically separated from WHS, was also designed to trace the sequential transport and fate of PCBs, including desorption, adsorption, dechlorination, and re-partitioning. PCBs, once desorbed from WHS, were immediately sequestrated to RAC and subject to dechlorination. Direct mixing of WHS with RAC was one-order of magnitude more effective for dechlorination than compartment configuration. Compared to their desorption-followed by-adsorption route, direct physical contact of RAC with PCBs bound to WHS exhibited negligible contribution to the availability of PCBs for dechlorination reaction. Addition of RAC even in compartment configuration facilitated PCBs desorption from WHS. However, slow desorption of PCBs limited overall performance, resulting in a five-order of magnitude lower dechlorination yield when compared with treatment of purely aqueous PCBs. The low dechlorination yield reflected real world complexities in treating 3.19% organic carbon-containing WHS aged with PCBs for 40 years. These observations were further supported when compared with results on clean Cesar Creek sediment spiked with 2-chlorinated biphenyls.
伊利诺伊州沃克根港的沉积物（WHS）受到多氯联苯（PCBs）的严重污染和老化，用负载钯铁纳米粒子的反应性活性炭（RAC）进行处理。实验室测试在 RAC 和 WHS 的直接混合配置中进行。还设计了一个隔室配置，其中 RAC 与 WHS 物理分离，以追踪 PCB 的顺序迁移和归宿，包括解吸、吸附、脱氯和再分配。一旦从 WHS 上解吸出来的 PCB 立即被隔离到 RAC 上，并进行脱氯反应。与隔室配置相比，WHS 与 RAC 的直接混合对脱氯的效果要高出一个数量级。与它们的解吸-随后吸附途径相比，RAC 与结合到 WHS 上的 PCB 的直接物理接触对 PCB 对脱氯反应的可用性几乎没有贡献。即使在隔室配置中添加 RAC，也会促进从 WHS 中解吸 PCB。然而，PCB 的缓慢解吸限制了整体性能，与处理纯水性 PCB 相比，脱氯产率低五个数量级。与用 2-氯联苯污染的清洁塞萨尔克里克沉积物的结果进行比较时，这种低脱氯产率反映了处理含有 3.19%有机碳且老化 40 年的 PCB 的实际情况的复杂性。
