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Phenomenological and Spectroscopic Analysis on the Effects of Sediment Ageing and Organic Carbon on the Fate of a PCB Congener Spiked to Sediment
Citation:
Choi, H., P. A. Nfodzo, W. A. Lawal, S. R. Al-Abed, AND Y. Seo. Phenomenological and Spectroscopic Analysis on the Effects of Sediment Ageing and Organic Carbon on the Fate of a PCB Congener Spiked to Sediment. D.S. Aga, W. Choi, A. Daugulis, G. Puma, G. Lyberatos and T.J. Hwa (ed.), JOURNAL OF HAZARDOUS MATERIALS. Elsevier Science Ltd, New York, NY, 239-240:325-332, (2012).
Impact/Purpose:
This study introduces the concept of full cycle transport, reaction, and fate of a spiked PCB into engineered sediment in the presence of target substrates in the environment. We present the first empirical and spectroscopic attempt to elucidate the nature of the subsequent reactions (i.e., sorption, desorption, dechlorination, and sequestration). Spectroscopic analysis of PCB binding to sediment matrix explains the effects of sediment ageing and organic carbon. Results from this study will therefore be of interest to scientists and engineers to obtain useful insights on PCBs mobility and thus develop effective remediation strategies.
Description:
This study assesses the full cycle transport and fate of a polychlorinated biphenyl (PCB) congener spiked to sediment to empirically and spectroscopically investigate the effects of sediment ageing and organic carbon on the adsorption, desorption, and reaction of the PCB. Caesar Creek sediment (CCS) was oxidized to remove amorphous organic carbon (AOC) followed by soot carbon (SC), spiked and aged with 2-chlorobiphenyl (2-ClBP), mixed with various aquatic solutions, and treated on reactive activated carbon (RAC) impregnated with palladized iron. Results showed that 2-ClBP sorption isotherms and kinetic parameters well reflected the critical influence of AOC and SC on the sorption behavior of 2-ClBP. Infrared analysis implied the presence of preferred 2-ClBP sorption sites within the sediment matrix. The shift in the C–H vibrational frequencies of 2-ClBP bound to CCS was more apparent in cases of higher organic content (particularly SC) and longer ageing time, which made 2-ClBP more sorbed and strongly bound to CCS and thus made it more difficult to desorb 2-ClBP. The ageing effect on 2-ClBP binding was more prominent in the presence of organic carbon. Only desorbed 2-ClBP was transported to the target RAC for its physical adsorption and chemical dechlorination.
