Abstract
Ph.D. (Chemistry)
As new analytical methods for monitoring water quality continue to advance and become more specific in their detection limits, geochemical modelling tools are also advancing due to increasing technological creations. These two disciplines of chemistry (analytical techniques and modelling) are aimed at ensuring clean and safe water for better quality of life. The goal of this study was to use analytical methods and geochemical modelling tools to monitor selected metals, anions, volatile organic compounds and non-volatile organic compounds from South African water systems. Two sets of samples were collected, namely, a set of seven and another set of six samples were collected from a wastewater treatment plant (WWTP) in the Gauteng province and surface water (river) in Kwa-Zulu Natal province, respectively. Inorganic and organic water contaminants were analysed using techniques such as; inductively coupled plasma mass spectroscopy (ICP-MS), ion exchange chromatography (IEC), high performance liquid chromatography (HPLC) and multi-dimensional gas chromatography – time of flight mass spectroscopy (GCxGC-TOF/MS).
A new hybrid database for geochemical modelling was developed from extracted experimental data. The modification of the database involved the merging of two already existing databases (Wateqf.dat and PHREEQ C.dat) with inclusion of data on five chlorinated organic compounds (COCs) namely; pentachlorophenol, three isomers of trichlorobenzene (TCB) and trichloroethylene. In order to enhance precision and accuracy, metal speciation, fate and transport calculations were carried out using the modified geochemical database. With this new hybrid database, a mobile application running on an android operating system (OS) was...