Development of analytical techniques for detection and remediation of polychlorinated biphenyls in soil and water samples

  • Ofure Ruth IDIALU

Student thesis: Doctoral Thesis

Abstract

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 Award14 Oct 2016
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorLorraine Gibson (Supervisor) & Christine Davidson (Supervisor)

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