Influential role of black carbon in the soil-air partitioning of polychlorinated biphenyls (PCBs) in the Indus River Basin, Pakistan.
Levels of polychlorinated biphenyls (PCBs) were assessed in surface soils and passive air samples from the Indus River Basin, and the influential role of black carbon (BC) in the soil-air partitioning process was examined. ∑26-PCBs ranged between 0.002-3.03 pg m(-3) and 0.26-1.89 ng g(-1) for passive air and soil samples, respectively. Lower chlorinated (tri- and tetra-) PCBs were abundant in both air (83.9%) and soil (92.1%) samples. Soil-air partitioning of PCBs was investigated through octanol-air partition coefficients (KOA) and black carbon-air partition coefficients (KBC-A). The results of the paired-t test revealed that both models showed statistically significant agreement between measured and predicted model values for the PCB congeners. Ratios of fBCKBC-AδOCT/fOMKOA>5 explicitly suggested the influential role of black carbon in the retention and soil-air partitioning of PCBs. Lower chlorinated PCBs were strongly adsorbed and retained by black carbon during soil-air partitioning because of their dominance at the sampling sites and planarity effect.
Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
Usman
U
Ali
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Jabir Hussain
JH
Syed
Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, PO: 45550, Pakistan.
Adeel
A
Mahmood
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Jun
J
Li
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Gan
G
Zhang
Centre for Chemicals Management, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK.
Kevin C
KC
Jones
Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: r_n_malik2000@yahoo.co.uk.
Riffat Naseem
RN
Malik
D000327:Adsorption; D000388:Air / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere; D002244:Carbon / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D005843:Geography; D000442:Octanols / Q000032:analysis; D010154:Pakistan; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D011786:Quality Control; D045483:Rivers / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D053260:Soot / Q000032:analysis*
D000393:Air Pollutants; D000442:Octanols; D012987:Soil; D012989:Soil Pollutants; D053260:Soot; D002244:Carbon; D011078:Polychlorinated Biphenyls
Adsorption; Black carbon–air partition coefficient; Indus River Basin; Octanol–air partition coefficient; PCBs; Soil–air partition model