Thesis (M.S. - Agronomy and Plant Genetics)--University of Arizona. / Includes bibliographical references.

Thesis (Ph. D. - Civil Engineering and Engineering Mechanics)--University of Arizona. / Includes bibliographical references.

Thesis (Ph. D. - Hydrology and Water Resources)--University of Arizona, 1989. / Includes bibliographical references (leaves 245-252).

Thesis (Ph. D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.

Thesis (M.S.)--University of Nevada, Reno, 2006. / "August, 2006." Includes bibliographical references (leaves 67-70). Online version available on the World Wide Web.

Thesis (MS)--University of Montana, 2010. / Contents viewed on July 14, 2010. Title from author supplied metadata. Includes bibliographical references.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 341-346).

Ozone is a powerful oxidant and disinfectant used in potable wastewater reuse to destroy specific harmful compounds, including pharmaceuticals, personal care products and endocrine disrupting compounds. Ozonation also increases the biodegradability of recalcitrant organic compounds and inactivates disease-causing microbes. However, bromate, a regulated possible human carcinogen can form when bromide is present due to natural or industrial sources. Pilot-scale testing on wastewater treatment plant effluent with high bromide concentrations showed that the addition of preformed monochloramine could reduce bromate formation by as much as 97%. Monochloramine addition was able to keep concentrations below the U.S. Environmental Protection Agency Maximum Contaminant Level of 10 µg/L while exceeding 3-log or 99.9% virus removal credit. Preforming monochloramine in separate carrier water prior to addition upstream of ozonation eliminated the potential for disinfection byproduct formation when monochloramine is formed in the main water flow. This also allowed for the mechanisms of bromate suppression by monochloramine to be examined without the influence of reactions between chlorine and dissolved organic matter present. This research can help increase the application of ozonation in water reuse. / MS / Ozone is a powerful oxidant and disinfectant used in potable wastewater reuse to destroy specific harmful compounds, including pharmaceuticals, personal care products and endocrine disrupting compounds. Ozonation also increases the biodegradability of recalcitrant organic compounds and inactivates disease-causing microbes. However, bromate, a regulated possible human carcinogen can form when bromide is present due to natural or industrial sources. Pilot-scale testing on wastewater treatment plant effluent with high bromide concentrations showed that the addition of preformed monochloramine could reduce bromate formation by as much as 97%. Monochloramine addition was able to keep concentrations below the U.S. Environmental Protection Agency Maximum Contaminant Level of 10 µg/L while exceeding 3-log or 99.9% virus removal credit. Preforming monochloramine in separate carrier water prior to addition upstream of ozonation eliminated the potential for disinfection byproduct formation when monochloramine is formed in the main water flow. This also allowed for the mechanisms of bromate suppression by monochloramine to be examined without the influence of reactions between chlorine and dissolved organic matter present. This research can help increase the application of ozonation in water reuse.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

This study examines whether recycled water (specifically grey water) is used in peri-urban agriculture in greater Port Elizabeth. It also investigates the socio-economic as well as environmental benefits of using recycled water in peri-urban agriculture. Community perceptions and narratives about the use of recycled water for farming purposes were also investigated. Study respondents were purposively selected from Motherwell and Uitenhage in Port Elizabeth. A qualitative research methodology and methods were used. This involved using purposive sampling to sample, select and interview 22 respondents and eight key informants. All the respondents were interviewed using in-depth semi-structured interviews. The study found that while many respondents have heard about water recycling, they are however not using recycled grey water for their peri-urban farming activities. Instead, peri-urban farmers continue to use water supplied by the municipality. Recycled water is mostly used for watering sport fields around Port Elizabeth. This continued usage of municipal water (instead of recycled water) is not only costly to the municipality but the individual farmers as well. The respondents were however aware of the benefits of using recycled water. These include economic (money saved from not paying irrigation water bills), environmental (nutrient contents found in recycled water) and socio-economic (conserving fresh available for use in other community purposes). The study recommends that the Nelson Mandela Metro Municipality should do more (through educational and environmental campaigns) to encourage peri-urban farmers to use recycled water in their farming activities.