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As human population increases, the need for water increases in domestic, agricultural, industrial and urban sectors. Wastewater reuse after treatment is gaining acceptance world wide, as availability of fresh water sources decreases. However, it is also important to point out social and cultural differences that still exist in different pars of the world including those where reuse of wastewater for food production or any domestic use is not yet acceptable. The major concerns with effluent reuse are primarily its impact on human health and environmental risk. As a result, effluent reuse should be undertaken with caution after careful consideration of the potential impacts and risks. This thesis examined the potential to use the hydroponics nutrient film technique to grow commercially important crops using secondary-treated domestic wastewater. The crops chosen were a fruit crop (Lycopersicon esculantum - tomato), a leafy crop (Beta vulgaris ssp. cicla - silver beet) and a flower crop (Dianthus caryophyllus - carnation). Secondary-treated domestic wastewater was chosen because of the reduced risk of pathogen and heavy metal contamination in the crops and due to the guideline requirements for use of treated effluent for food crops. The possibility of using the effluent after the hydroponics treatment for further irrigation was also studied. The ability of secondary-treated effluent to supply adequate nutrients to the crops was assessed relative to a commercially available hydroponics solution (Chapter 3). The amount of time the solution was left in the system (nutrient solution retention time) was dependant on the plant uptake of the solution. The results obtained showed that the nutrients in secondary treated effluent was adequate for the carnations, but not for the food crops. The food crops from both treatments were compared to the produce purchased from a supermarket. The food crops showed signs of nutrient deficiency, particularly nitrogen. Based on the findings of the first experiment, the nutrient solution retention time was amended to 14 days. The carnations were not tested with the shorter nutrient solution retention time (NSRT) because they performed well in the previous trial with the longer nutrient solution retention time. The edible food crops performed better and did not show signs of nutrient deficiency when the nutrient solution retention time was reduced to 14 days. Further statistical analysis was conducted with the data from Chapters 3 and 4. Nutrient and water balances were calculated and the possible reason that the plants grown in the 14-day nutrient solution retention time took up more water, was a result of increased nutrients and better growth. A simple model was constructed to calculate height of the plants using multiple regression. The model was validated against the data collected from this study. The experiment conducted in Chapter 6 determined the nutritional quality of the food crops. The harvests from the wastewater and commercially available hydroponics solution were compared to produce purchased from a supermarket and tested for total caroteniods, total soluble solids and ascorbic acid concentrations. The nutritional quality of the wastewater grown produce was comparable to those grown in the hydroponic solution and those purchased. The risk of pathogen contamination to food crops and the die-off of pathogens in the hydroponic channels were studied in Chapter 7. This was tested by spiking the commercial hydroponic medium with Escherichia coli and Salmonella typhimurium and monitoring bacterial pathogen die-off in the secondary treated domestic wastewater. The pathogen quality of the crop was tested in all treatments as well as on organically grown produce found at a local supermarket. The results of this experiment did not show any contamination on the surface of the food crops or within the food crops. This study demonstrated that growing tomatoes, silver beet and carnations using secondary-treated domestic wastewater was successful when the nutrient solution retention time was adjusted to the optimum level. In arid, developing and remote communities, this system is ideal as it conserves and reuses water for commercially important crops without compromising the health of the environment or of human beings. It can also be implemented in urban areas, as the system can be scaled according to the availability of space. In addition to this, the effluent after going through this system can be used for open irrigation as it meets the World Health Organisation guidelines. However, a number of additional concerns need further investigation. They include the transmission risk of other types of pathogen, which depends on the source of wastewater, and the effects of hormones and antibiotics on food crops and their effect on human health.

Thesis (M.S.)--Marshall University, 2008. / Title from document title page. Includes abstract. Document formatted into pages: contains vi, 71p. Includes bibliographical references p. 69-71.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xiii, 178 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 112-115).

Thesis (MScAgric)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Despite millions of Rands being disbursed to the three hydroponic projects in the Nelson Mandela Bay Municipality by Provincial Departments, Development Agencies and NGOs, relatively little is known about the impact of these projects. There is too little evaluative research on the effectiveness of such development projects. Questions arose as to what made these projects fail and what was required for sustainability over their intended life-spans. Evaluations assess a project’s ability to be sustained by examining different aspects of sustainability, including technical soundness, skills transfer, political effect, economic viability, and institutional, organizational and management effectiveness. This study has revealed that hydroponic production is a very challenging business that requires close monitoring, intense technical knowledge, and continuous learning. Moreover it is very costly, while profit generation is quick and the market central for the sustainability of this kind of project. The findings of this study also revealed that no proper feasibility study was conducted including selection of beneficiaries, no monitoring by funders and donors, no transfer of skills and no continuous empowerment of project members. Project members also indicated that they are aware of the causes of their project closures and that they are willing to participate in hydroponics production initiatives again because of the potential that these projects have.

The world’s population is growing at an average of 1.2 percent per annum and forecasts see the global population reaching 9.6 billion by 2050. This places great demands on the sustained production capacity of agricultural organisations to meet the desperate need for nutrition. This problem will continue to persist if production methods do not evolve to improve production and quality. Hydroponics and Controlled Environment Agriculture (CEA) was first seen in Rome during the 1st Century. Then sixteen Centuries later Greenhouses were developed in France and England as experimental hydroponics for basic laboratory research. Rapid expansion took place from about the 1950’s in areas where traditional openenvironment agriculture was difficult or impossible such as the deserts of Iran, Abu Dhabi and California. Sixty-five years later in 2015 hydroponics and CEA are well established around the world with thousands of hectares under propagation. Hydroponics is a method of agricultural production that has been refined over the years to become an exact science. Through the application of technology and know-how the physiological processes within plants can be manipulated and controlled to produce superior results. These results require less land area and less water to accomplish. It can be seen, based on this development, that hydroponics is such an evolution that has the capacity to meet the needs of a growing global population and its nutritional needs. The challenge lies, though, in the scientific understanding and application of knowledge in growing and managing a hydroponics farm. This study seeks to determine the internal data and external information needs of farmers in the hydroponics industry. This data and information will be integrated into a Farm Management Information System (FMIS) model that will be used for decision making, report generation and documentation. The problem leading to this study is the dissemination of data and information sources that are currently underutilised and difficult to access. In determining the internal data and external information needs, an empirical study was conducted using structured interview. Thirty farm managers were interviewed to assess what their current information system consisted of, whether they had a need for an FMIS and what internal data and external information was needed which related to four functional components of hydroponic farming. The results of this study indicate that there is a need for an FMIS for the hydroponic industry in South Africa. The results also indicate that managers are not fully satisfied with the performance of their current information system and would be interested in considering alternative information systems. Data points relating to the four functional components were assessed and integrated into an FMIS model for the hydroponic industry. This model sets out to integrate internal data and external information for purposes of decision making, report generation and documentation.

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Thesis (M. Arch.)--University of Hong Kong, 2004. / Includes special report study entitled: Lost space: prodigy of Hong Kong. Also available in print.