M. Tech. Chemical Engineering / Environmental pollution due to heavy metals is a global crisis. Contamination as a result of heavy metals from industries such as mining operations, electroplating facilities, etc. pose serious threats to the aquatic ecosystem, people and the environment. Lead (Pb), cadmium (Cd), zinc (Zn), copper (Cu), mercury (Hg) and nickel (Ni) are common examples of heavy metal ions often detected in most effluents. They are characterised by their non-biodegradability, toxicity and tendency to accumulate in living organisms, and thereafter, cause various diseases and disorders. In this study, two nano-structured composite bio-sorbents were prepared to determine their metal binding capacity, effect of solution pH, contact time and elution in a magnetically assisted adsorption system. Consequently, this study aims to develop magnetically assisted adsorption process for industrial wastewater treatment for re-use.

A research project report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering (Civil Engineering). Vanderbijlpark, 2016 / South Africa is a semi-arid country with an average rainfall of 450 mm per annum. According to the Department of Water Affairs, the total registered water usage in 2013 met the estimated 2025 high water requirement of 17.3 billion m3/annum. Therefore, the need had arisen to reduce water consumption and increase water supply to ensure the sustainability of our nation’s water resources. Many studies show that wastewater reuse or water reclamation is an under-utilized and very viable water conservation concept in South Africa. The reuse of wastewater for direct potable or direct non-potable reuse is a highly debated topic requiring frequent engagement and investigation. Although direct reuse for potable uses is often more contentious than direct reuse for non-potable uses, it is worth investigating for possible future implementation at certain water scares areas. Hence, this study investigated the possibility of the future implementation of direct wastewater reuse at Hartbeesfontein - a selected South African community, for potable or non-potable use. The study incorporated potential users’ perceptions, the cost implications of reuse and water saving potential by means of different water balance models. The survey conducted, measuring the intention of the residents from Hartbeesfontein to accept direct wastewater reuse for potable and non-potable use, revealed the community’s overwhelming acceptance (about 70%) of a reuse system should it be implemented in the future. The community’s preference for wastewater reuse for non-potable use (75%) was higher than for potable use (67%). Hypothetically, it would be possible to reuse 85% of the community’s daily demand for potable use, if all the wastewater collected at the wastewater treatment plant could be treated. It would then mean that the municipality will only need to provide 15% of the daily water demand. The option to reuse wastewater for non-potable use (i.e. to supply an industry) could save the community 22% its daily water demand. In this study, the cost of wastewater treatment for potable use was approximately 350% higher than the cost of potable water supplied by the Midvaal Water Company. The cost of treating wastewater for non-potable use however was approximately 46% less than the cost of potable water supplied by the Midvaal Water Company. By incorporating the outcomes of the water balance, perceptions of the community and analysis of the different wastewater reuse scenario costs, it was evident from the study that direct wastewater reuse for non-potable industrial application was the most viable water reuse option for Hartbeesfontein. / MT2017

M.Ing. (Civil Engineering) / To relieve the extreme pressure placed on overburdened water and wastewater infrastructure, the reuse of light wastewater was identified as a possible source of water supply for non-potable applications. The light wastewater discharge intercepted on-site can be recycled, treated and thereafter distributed to fixtures for agricultural, sanitation and gardening based activities. Sources for this light wastewater stream includes bathroom showers, bath tubs, hand wash basins including that of kitchens, laundry and washing machine outflows of recyclable quality. This type of re-usable water is called greywater (GW). This on-site re-use concept has potential to offer greater potable water savings if correctly implemented. For the purpose of this research, this particular type of waste stream excluding the kitchen and laundry discharge was the water source considered for the supply to this greywater treatment plant (GWTP). In 2009, the Water Research Commission (WRC) funded a greywater pilot study in a joint venture between the University of Witwatersrand (WITS) and the University of Johannesburg (UJ). Over the last few years, this project had progressed with new outcomes each year. The pilot GWTP at Unit 51, Student Town, UJ in Auckland Park was used for the purpose of this study. The selected reuse application for the GW effluent was for toilet flushing. GW was supplied to two toilets in a residential student complex housing 16 female and male students i.e. 8 students on each floor. The highlights of the WRC study included: a lack of satisfactory treatment efficiency and a well-defined protocol to address the problems associated with the slightly poor quality of effluent produced (i.e. unpleasant odours, greyish appearance and the unacceptable microbial count). Determining and addressing the user perceptions and user education about GW usage, respectfully, was a significant component in the successful management of the project. In this report, a practical evaluation of three crucial components of the GWTP was completed. These three components viz. treatment efficiency, user perceptions and quality standards, were common aspects of concern for existing decentralised GWTP’s within residential or small commercial stands.

The Bottelary River area is located in a Mediterranean climate region, where the agricultural sector plays an important role. During the dry summer season, there is not enough precipitation to meet the agricultural irrigation requirements. Some farmers extract river water which is practically the final treated effluent from the Scottsdene Wastewater Treatment Works to irrigate crops. This research investigated the use of treated effluent for agricultural irrigation in this area, particularly focused on the effluent quality, farmers perception, and the potential extent.

The Bottelary River area is located in a Mediterranean climate region, where the agricultural sector plays an important role. During the dry summer season, there is not enough precipitation to meet the agricultural irrigation requirements. Some farmers extract river water which is practically the final treated effluent from the Scottsdene Wastewater Treatment Works to irrigate crops. This research investigated the use of treated effluent for agricultural irrigation in this area, particularly focused on the effluent quality, farmers perception, and the potential extent.

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.

Submitted in fulfillment for the requirements of the degree of Master of Engineering, Department of Chemical Engineering, Durban University of Technology, KwaZulu-Natal, South Africa, 2016. / A large fraction of the world's population, around 1.1 billion people, do not have access to acceptable sources of water. In South Africa there is a growing pressure on the available freshwater resources. New sources of freshwater supply are becoming increasingly scarce, expensive or politically controversial. This has led to large scale interest in the application of water reclamation and reuse of domestic, mining and industrial wastewater as an alternative water supply sources. This is becoming critical to sustain development and economic growth in the Southern African region. This research aims at providing both social and scientific information on the importance of greywater reuse and recycling as an alternate source to aid water demand management under South African conditions. The approach to this research work was divided into two main thrusts: the first was to gain an understanding of the public attitudes towards the idea of reusing greywater that is usually perceived as wastewater which pose health concerns. The second was to provide an understanding of typical greywater quality in a peri-urban community in Durban, South Africa as well as investigate the suitability of a horizontal roughing filtration system in reducing pollutant strength of contaminants found in greywater for non-potable reuse applications. In order to achieve the central aim of this research study, the following objectives were considered: • Investigation of public perception and attitudes towards the reuse of greywater. • Determination of greywater quality in a peri-urban community in Durban South Africa. • Investigation of the performance of a horizontal roughing filtration system for the treatment of greywater collected from a peri-urban community in Durban, South Africa. It was important to have an understanding of public perception and attitudes towards the reuse of greywater because of the fact that the success of any reuse application depends on the acceptance of the public. The methodological approach for this aspect of the research work involved administering of structured questionnaires to residents within the community through field visits. The questionnaire addressed issues related to attitudes towards the reuse of greywater, perceived advantages related to the reuse of greywater and concerns related to public health issues regarding the reuse of greywater. The successful implementation of any greywater treatment process depends largely on its characteristics in terms of the pollutant strength. The methodological approach for this aspect of the research work involved physico- chemical characterization of the greywater collected from different sources within the households in the peri-urban community. Greywater samples were collected from the kitchen, shower and laundry within each of the households. This aspect of the research work was undertaken to gain an understanding of greywater quality from different sources within and between households. In order to achieve the third objective of this research work, a pilot plant horizontal roughing filtration system was designed and fabricated for the treatment of greywater. The system consisted of three compartments containing different sizes of gravel that served as the filter media. This was done in order to investigate the effect of varying filter media size on the performance of the horizontal roughing filtration system in treating greywater. The system had an adjustable manual valve used in varying the filtration rate. The impact of varying filtration rate on the performance of the horizontal roughing filtration system in treating greywater was also investigated. The main findings of this research were: • From the survey conducted, the percentage of the public willing to accept the reuse of greywater within the community was far higher than the percentage opposing its reuse. Concerns have often been expressed by the public that the reuse of greywater could pose possible adverse effects to public health. However, in this pilot study it was found that a higher percentage of respondents (>60%) disagree that the reuse of greywater could negatively impact on public health compared to less than 20% of the respondents that agree. An interesting finding of this study was that a greater percentage of the respondents were willing to have a dual water distribution system installed in their current place of residence. • The physico-chemical characterization of greywater from different sources within the households investigated indicated that, the quality of greywater varies considerably between all sources and from household to household. None of the households investigated produced the same quality of greywater. It was also found that greywater generated from the kitchen contains the most significant pollutants in terms of the physico-chemical parameters considered in this study compared to the other sources within the household. • The pilot plant horizontal roughing filtration system demonstrated its suitability for the treatment of greywater for non-potable reuse applications. It was observed that 90% turbidity and 63% Chemical Oxygen Demand reduction was achieved over the entire duration of operation of the horizontal roughing filter. It was also observed that the removal efficiency was significantly higher in the compartment with the smallest filter media size and the removal efficiency was significantly higher at lower filtration rates. It is therefore concluded from the investigation conducted in this research that the role of the public is a vital component in the development and implementation of any reuse system / application. It was found that there was a relatively high level of acceptance for the reuse of greywater among the respondents within the community where the study was conducted. The greywater characteristics results obtained from this investigation indicated the necessity of treatment prior to disposal in the environment. Also, a low BOD5/COD ratio of 0.24, which is significantly lower than 0.5, is an indication that the greywater generated from the community cannot be easily treated using biological treatment processes and/or technologies. The pilot horizontal roughing filtration system used for the treatment of greywater in this study demonstrated its suitability for the treatment of greywater for non-potable reuse applications such as irrigation, toilet flushing and washing activities. / M

A Research Report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering University of Witwatersrand Johannesburg, February 2016 / A growing population, rapid urbanisation, and climate change are increasing the pressure on water supplies. The chances of finding new freshwater sources for urban areas are becoming nearly impossible, implying that existing water supplies must go further to satisfy the basic need of potable water. Water reclamation involves the treatment of wastewater to meet defined water quality standards so that it may be reused. Direct potable reuse refers to the introduction of wastewater, which has been treated to meet specified standards, directly into the potable water supply distribution system. Water reuse has become an attractive alternative since wastewater is constantly being produced by populations, which can be treated for reuse. This study examines the sustainability of water reclamation for potable purposes, through an assessment of the Beaufort West Water Reclamation Plant, which includes interviews with the plant manager and process controllers, as well as a review of the relevant documentation. The study employs the use of economic, environmental and societal indicators as a tool in determining the sustainability of water reclamation. The results of the research show that direct potable reuse may be a sustainable solution to reducing the stress on water resources, although certain aspects of the reclamation process require further development in order to progress toward sustainability. In order to provide a long term solution, water reclamation will have to be implemented in conjunction with other water conservation strategies. / MT2017

Thesis (MSc. (Geography and Environmental Science)) -- University of Limpopo, 2015. / Fresh water is a finite and vulnerable resource, essential to sustain life, development and the environment. Growth in population and economic activities have contributed to water scarcity, which is a frequent challenge in rural and township communities in South Africa. This study aimed at investigating onsite greywater reuse as a water conservation method in Lepelle-Nkumpi local municipality, Limpopo province. The study described the socio-economic characteristics, assessed the accessibility and availability of water supply, and ascertained the coping mechanisms for water scarcity as well as the perceptions and reuse of greywater. Four percent respondents each were selected from two settlements, namely, Mashite village and Lebowakgomo township (Zone F). Mashite village had a population size of 5314 people (1231 households) and Lebowakgomo Zone F had 5903 people and (1924 households). A systematic random sampling method was used to select the required households from the two settlements. Both open and close ended questionnaires were used. A Geographical Positioning System was also used to collect the absolute location of available taps in the study area. Data collected were analysed using SPSS version-22 and Arc GIS 10.1. The study found out that the socio-economic characteristics of importance on onsite greywater reuse included highest qualification, household size and employment status, but they varied in these two areas. In Mashite village the majority of the respondents went to secondary school (59%) as compared to Lebowakgomo Zone F where the majority (72%) attained tertiary qualification. Household size mean in Mashite is 6.18 as compared to Lebowakgomo Zone F (2.77). Sixty four percent of respondents in Mashite village were unemployed, whereas in Lebowakgomo 69% were employed. Water usage in the two areas differed; in Mashite village where they use less water (250 to 840 litres) as compared to Lebowakgomo Zone F, where more water is used (5900 to 8001 litres). In Mashite village, 87% of the respondents could not access water due to inaccessibility of taps and unavailability of water as compared to Lebowakgomo zone F (100%). It was also found that the Mashite community sometimes go for a period of two to three months without tap water whereas in Lebowakgomo water was comparatively regular. As a result both communities resorted to rainwater harvesting and greywater reuse. Seventy six percent (76%) of respondents in Mashite village and 30% of the respondents in ii Lebowakgomo Zone F harvested rainwater as a coping mechanism of water scarcity. Perceptions of greywater reuse were higher (76%) in Lebowakgomo Zone F compared to Mashite village (49%). A higher percentage of Mashite village respondents (98%) reuse greywater compared to Lebowakgomo Zone F respondents (59%). Both areas use greywater as water conservation method. These results reinforce the potential of domestic greywater reuse as an alternative for freshwater requirement. Greywater reuse as a water conservation method especially in villages can be used to alleviate the extent of water scarcity. / National Research Foundation (NRF)

PhD (Environmental Sciences) / Department of Hydrology and Water Resources / See the attached abstract below