School of Environmental Science and Engineering, POSTECH, Pohang 790-784, Republic of Korea.
Corporate R&D, LG Chem Research Park, Daejeon 305-380, Republic of Korea.
J Hazard Mater. 2015 Apr 28;287:335-41. doi: 10.1016/j.jhazmat.2015.02.001. Epub 2015 Feb 3.
The persistence of polychlorinated biphenyl (PCB) Aroclor 1248 in soils and sediments is a major concern because of its toxicity and presence at high concentrations. In this study, we developed an integrated remediation system for PCBs using chemical catalysis and biodegradation. The dechlorination of Aroclor 1248 was achieved by treatment with bimetallic nanoparticles Pd/nFe under anoxic conditions. Among the 32 PCB congeners of Aroclor 1248 examined, our process dechlorinated 99%, 92%, 84%, and 28% of tri-, tetra-, penta-, and hexachlorinated biphenyls, respectively. The resulting biphenyl was biodegraded rapidly by Burkholderia xenovorans LB400. Benzoic acid was detected as an intermediate during the biodegradation process. The toxicity of the residual PCBs after nano-bio treatment was evaluated in terms of toxic equivalent values which decreased from 33.8×10(-5)μgg(-1) to 9.5×10(-5)μgg(-1). The residual PCBs also had low cytotoxicity toward Escherichia coli as demonstrated by lower reactive oxygen species levels, lower glutathione peroxidase activity, and a reduced number of dead bacteria.
多氯联苯 (PCB) Aroclor 1248 在土壤和沉积物中的持久性是一个主要关注点，因为它具有毒性并且浓度很高。在这项研究中，我们使用化学催化和生物降解开发了一种用于 PCB 的综合修复系统。在缺氧条件下用双金属纳米粒子 Pd/nFe 处理实现了 Aroclor 1248 的脱氯。在所研究的 Aroclor 1248 的 32 种 PCB 同系物中，我们的工艺分别脱除了三氯、四氯、五氯和六氯联苯的 99%、92%、84%和 28%。生成的联苯被 Burkholderia xenovorans LB400 迅速生物降解。在生物降解过程中检测到苯甲酸作为中间产物。纳米-生物处理后残留 PCB 的毒性根据毒性当量值进行评估，从 33.8×10(-5)μgg(-1) 降低到 9.5×10(-5)μgg(-1)。残留 PCB 对大肠杆菌的细胞毒性也较低，这表现为活性氧水平较低、谷胱甘肽过氧化物酶活性降低以及死亡细菌数量减少。
