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Thesis (M.Sc.(Civil Engineering))--University of the Witwatersrand, Faculty of Engineering, 1989.

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Dissolved organics in wastewater samples were separated into three size fractions (0-1,000 amu, 1,000-10,000 amu, and 10,000 amu-0.22 m) using ultrafiltration (UF) membranes. The mass distribution within each fraction was adjusted by using a new permeation coefficient model to account for membrane rejection. Dissolved organic and soluble BOD (sBOD) removals in a trickling filter were studied for the different size fractions. The Logan trickling filter model was recalibrated and used to generate predicted removals by size fraction of sBOD, dissolved organic carbon (DOC), and biodegradable DOC (bDOC) for a given influent. Although there was moderate agreement between observed and predicted removals, more investigation is needed to explain shifts in material between different size fractions. Of the three parameters, bDOC may offer a better parameter for modelling trickling filter performance than sBOD.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

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Many methods for the quantitative concentration of small amounts of viruses from natural water supplies have been considered. One of the most promising of these is the adsorption of viruses onto a 0.45pm cellulose nitrate membrane filter apparatus. A quantity of water is passed through the filter by gravity or pressure filtration. The viruses present in the water are adsorbed onto the membrane and are subsequently eluted by the use of a beef extract eluant. The virus-containing elution is then layered upon tissue culture, preferably the BGM cell line, for isolation by the plaque method. The isolated virus is then identified by serological techniques.The research presented here utilized the cellulose nitrate membrane filter system for the detection of viruses from local waterways and sewage treatment influents and effluents. Examination of the water was done for the Enterovirus group of viruses consisting primarily of the Echovirus, Coxsackievirus, and Poliovirus groups.Although viral cytopathic effect was detectable in a few cell cultures innoculated with collected water samples, no virus was isolated and identified by serological techniques or electron microscopy. The use of continuous cell lines produced numerous problems during this study. Subsequently, any viruses in positive CPE flasks could not be repassaged in BGM cultures. No viruses could be identified by neutralization in tissue culture. Identification of the positive flasks could not be made by electron microscopy.