In this study, GC-MS methods were developed for identifying and quantifying nineteen and five pre-selected PCB congeners in solution. The developed methods were repeatable (≤ 4.9 %) and reproducible (≤ 7.7 %) with detection limits of 1.25 - 15 ng µL-1 . The extraction of PCBs from soil and water samples was achieved using the ASE and C18 (EC) SPE methods with recoveries of 81 - 94 % and 41 - 49 % respectively. Although none of the target PCB congeners were detected in soil and water samples collected from Lagos, Nigeria, similar recoveries were obtained from spiked samples; indicating that the developed methods could be satisfactorily used to extract PCBs from environmental samples. The adsorption of PCBs from aqueous solutions onto activated carbons - PAC, GAC and EAC was examined using batch experiments. The removal efficiencies obtained for PAC (75 - 90 %), GAC (79 - 99 %) and EAC (60 - 74 %) indicated that each AC could be successfully used to remove PCBs from water. In contrast to EAC, which had a slight decrease in performance as the concentration of aqueous solution increased, a significant decrease in performance was observed for PAC and GAC. The equilibrium data obtained for each AC was well described by the Langmuir isotherm model corresponding to the presence of a homogeneous surface. Amongst the three ACs, EAC had the highest maximum adsorption capacity (35 mg g -1 ) compared to PAC (29.4 mg g -1 ) and GAC (30.4 mg g -1 ). The adsorption kinetic data obtained for each AC had a better fit to the pseudo second-order kinetic model indicating that chemisorption was responsible for the sorption of PCBs onto each AC. The optimum performance of the three ACs was achieved at solution pH 3.
| Date of Award | 14 Oct 2016 |
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| Original language | English |
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| Awarding Institution | - University Of Strathclyde
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| Supervisor | Lorraine Gibson (Supervisor) & Christine Davidson (Supervisor) |
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