title: Nano/bio treatment of polychlorinated biphenyls with evaluation of comparative toxicity.
abstract: 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.
authors: School of Environmental Science and Engineering, POSTECH, Pohang 790-784, Republic of Korea.
authors: Thao Thanh
authors: TT
authors: Le
authors: School of Environmental Science and Engineering, POSTECH, Pohang 790-784, Republic of Korea.
authors: Khanh-Hoang
authors: KH
authors: Nguyen
authors: Corporate R&D, LG Chem Research Park, Daejeon 305-380, Republic of Korea.
authors: Jong-Rok
authors: JR
authors: Jeon
authors: Division of Advanced Nuclear Engineering, POSTECH, Pohang 790-784, Republic of Korea; Environmental Sciences Department, Brookhaven National Laboratory, Upton, NY, USA.
authors: Arokiasamy J
authors: AJ
authors: Francis
authors: School of Environmental Science and Engineering, POSTECH, Pohang 790-784, Republic of Korea. Electronic address: yschang@postech.ac.kr.
authors: Yoon-Seok
authors: YS
authors: Chang
mesh_terms: D001140:Aroclors / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D019817:Benzoic Acid / Q000378:metabolism; D019117:Burkholderia / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods; D004926:Escherichia coli / Q000187:drug effects; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity
chemical_list: D001140:Aroclors; D012989:Soil Pollutants; C028617:aroclor 1248; D010165:Palladium; D019817:Benzoic Acid; D007501:Iron
keywords: Aroclor 1248; Bimetallic nanoparticles Pd/nFe; Dechlorination; Nano-bio treatment; Nanotoxicity