title: Decontamination of PCBs-containing soil using subcritical water extraction process.
abstract: Polychlorinated biphenyls (PCBs) are one of the excision compounds listed at the Stockholm convention in 2001. Although their use has been heavily restricted, PCBs can be found in some specific site-contaminated soils. Either removal or destruction is required prior to disposal. The subcritical water extraction (SCWE) of organic hazardous compounds from contaminated soils is a promising technique for hazardous waste contaminated-site cleanup. In this study, the removal of PCBs by the SCWE process was investigated. The effects of temperature and treatment time on removal efficiency have been determined. In the SCWE experiments, a removal percentage of 99.7% was obtained after 1h of treatment at 250°C. The mass removal efficiency of low-chlorinated species was higher than high-chlorinated congeners at lower temperatures, but it was oppositely observed at higher temperatures because the lower chlorinated congeners are formed by dechlorination of higher chlorinated congeners. Gas chromatography/mass spectrometry analysis confirmed that the PCBs underwent partial degradation. Several degradation products including mono- and di-chlorinated biphenyls, oxygen-containing aromatic compounds, and small-size hydrocarbons were identified in the effluent water, which were not initially present in the contaminated soil.
authors.affiliation: Department of Environmental Engineering, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Mohammad Nazrul
authors.initials: MN
authors.lastname: Islam
authors.affiliation: Department of Environmental Engineering, Chonnam National University, Gwangju 500-757, Republic of Korea; Soil Technology Research Institute, Chonnam National University, Gwangju 500-757, Republic of Korea. Electronic address: parkjeo1@jnu.ac.kr.
authors.forename: Jeong-Hun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Environmental Engineering, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Moon-Su
authors.initials: MS
authors.lastname: Shin
authors.affiliation: Department of Environmental Engineering, Chonnam National University, Gwangju 500-757, Republic of Korea; Soil Technology Research Institute, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Ha-Seung
authors.initials: HS
authors.lastname: Park
mesh_terms: D003666:Decontamination / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000737:chemistry* / Q000302:isolation & purification; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry* / Q000302:isolation & purification; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014867:Water; D011078:Polychlorinated Biphenyls
keywords: PCBs; Removal efficiency; SCWE; Soil