Date of Award
Civil and Environmental Engineering
Seth, Rajesh (Civil and Environmental Engineering)
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Fate and transport of chemicals of environmental concern throughout municipal wastewater treatment plants (MWTPs) affect the safety of human and environmental health. Understanding of the fate of historic and emerging contaminants in MWTPs allows for consideration and prediction of potential environmental loadings and subsequent risk assessment. The aim of this thesis was to develop a robust and reproducible method to discern partitioning of a suite of chlorobenzenes (CBs) to well-characterized colloidal organic carbon (COC) of MWTP raw influents. Preliminary investigations support the use of MeOH cosolvent at volume fractions up to 1%. Given that cosolvent may also interact with COC directly, a 0.01% MeOH volume fraction was used in all studies. Henry's law constants (HLCs) used to determine the partitioning coefficient must be accurate and exhibit marked variability in the literature, thus calculating experiment-specific HLCs was needed. HLCs determined for the CBs ranged from 29.9-56.5 Pa m3 mol-1. Ultrafiltration fractionation was used to separate colloidal fractions followed by various techniques to characterize the COC. The major finding of size fractionation was the abundance of mass under the 1 kDa size fraction (ca. 70%). Sample preparation and liquid-state 1H NMR has not been previously used and serves as a valuable evolution for sample processing and COC characterization. The partitioning of CBs to MWTP colloids under 1.5 ╡m resulted in logKCOC values of 3.86, 3.89, and 3.19 for TeCB, PeCB, and HCB, respectively; these values did not follow trends based upon hydrophobicity. Contrary to expectations based on literature investigations COC under 1 kDa participated in partitioning with logKCOC values of 4.30, 4.36, and 3.74 for TeCB, PeCB, and HCB, respectively.
McPhedran, Kerry, "Partitioning of chemicals of concern to colloidal organic matter in municipal wastewater" (2012). Electronic Theses and Dissertations. 405.