South Africa is currently experiencing water shortage crisis, a challenge that has been attributed not only to the scarcity of freshwater, but also to fast degrading water quality. Factors such as rapid urbanisation, population and economic growth, climate change as well as poor operational and maintenance of many of the exisiting water/wastewater treatment facilities have been acknowledged as important contributors to degrading water quality in the country. Untreated or inadequately treated discharged wastewater effluents constitute point source pollution to many freshwater environments in South Africa. Hence, it becomes imperative to evaluate wastewater discharges in other to protect the scarce freshwater resource, the environment and public health. Over a twelve-month sampling period (September 2012 to August 2013), we assessed the bacteriological, virological and physicochemical qualities of the discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. For the physicochemical assessment, a total of 144 final effluent samples were collected from both the final effluent tanks (FE) and the discharge points (DP) of the treatment facilities. Physicochemical parameters including pH, temperature, turbidity, total dissolved solids (TDS), dissolved oxygen (DO), electrical conductivity (EC) and free chlorine concentration were determined on site while biological oxygen demand (BOD), nitrate (NO3-), nitrite (NO2-), phosphate (PO4-) and chemical oxygen demand (COD) were determined in the laboratory. The bacteriological analysis of the samples was done using standard membrane filtration (MF) technique. Bacterial group assessed included: faecal indicator bacteria (faecal coliforms and E. coli) and Vibrio species, while the antibiotic susceptibility profiles of selected E. coli and Vibrio species isolates against some selected antibiotics commonly used in human therapy and veterinary medicine were determind using the standard agar-disc diffusion method. The occurrence and concentrations of human enteric viruses including: human adenovirus (HAdV), hepatitis A virus (HAV) and rotavirus (RoV) in the samples were determined by TaqMan-based real-time polymerase chain reaction (qPCR) following concentration by adsorption-elution method. The physicochemical characteristics of the samples ranged as follows: pH (6.5 – 7.6), TDS (95 – 171 mg/L), EC (134 – 267 μS/cm), temperature (12 – 27 °C), turbidity (1.5 – 65.7 mg/L), free chlorine (0.08 – 0.72 mg/L), DO (2.06 – 9.81 mg/L), BOD (0.13 – 9.81 mg/L), NO3- (0 – 21.5 mg/L), NO2- (0 – 0.72 mg/L), PO4- (0 – 18.3 mg/L) and COD (27 – 680 mg/L). Some of the characteristic such as pH, TDS, EC, temperature, nitrite and DO (on most instances) complied with recommended guidelines. Other characteristics, however, including turbidity, BOD, nitrate, phosphate and COD fell short of the recommended guidelines. All the 48 samples analysed for bacteriological qualities tested positive for the presence of the bacterial groups with significant (P≤0.05) seasonal variation in their densities. Faecal coliforms were detected in counts ranging from 1 CFU/100ml to 2.7 × 104 CFU/100ml. Presumptive E. coli counts ranged generally between 1 CFU/100ml – 1.4 × 105 CFU/100ml while counts of presumptive Vibrio species ranged between 4 CFU/100ml – 1.4 × 104 CFU/100ml. Molecular identification of the presumptive isolates by polymerase chain reactions PCR gave positive reaction rates of 76.2 percent (381/500) and 69.8 percent (279/400) for E.coli and Vibrio species respectively. The antibiotic susceptibility profiling of 205 PCR-confirmed Vibiro isolates against 18 commomly used antibiotics showed resistance frequencies ranging from 0.5 percent (imipenem) to 96.1 percent (penicillin G) at recommended breakpoint concentrations. Eighty-one percent (166/205) of the Vibrio isolates showed multidrug resistance (resistance to 3 or more antibiotics) with the most common multiple antibiotic resistance phenotype (MARP) being AP-T-TM-SMX-PG-NI-PB, occurring in 8 isolates.

This research aimed to firstly confirm the hypothesis that the current management of sewage sludge generated during the treatment of wastewater in the Eastern Cape Province of South Africa is poor and, as such, this material poses a threat to local environmental and human health. Secondly, through a rational design approach, the current research also aimed to design and assess the suitability of a novel integrated process incorporating appropriate technologies for improved sewage sludge management. The lack of an appropriate tool for the assessment of the integrated process necessitated the development of an appropriate technology assessment (TA) methodology based on environmental, technical, social and economic criteria. A combination of informal participatory methods such as semi-structured interviews and formal research methods including questionnaires, risk assessment exercises and laboratory analyses were used. Based on the above it was estimated that 116 tons dry sludge were generated in the province per day and that the concentration of heavy metals present in the sludge was generally within the limits for reuse on agricultural land. Furthermore the sludge from all sample sewage treatment works (STWs) was found to be free of any detectable pathogens. Despite the above, a preliminary risk assessment and chemical analysis revealed that existing sludge management practices at sample STWs posed a threat to the environment, particularly to water resources and exacerbated the problems associated with the discharge of poorly treated municipal wastewater. The root causes of the poor sludge management were considered to be a lack of non-regulatory incentives and financial resources. Highly integrated ecologically engineered systems were thought to offer a solution to the dual problem of poor sludge management and municipal effluent treatment, while providing necessary economic incentives. To facilitate the design of a system appropriate to local conditions, it was necessary to first develop a rational design methodology, which incorporated a detailed TA step. The result of the design process was an Integrated Waste Beneficiation Facility (IWBF) that incorporated a number of process units comprised of appropriate technologies including composting, vermicomposting, algal ponding technology and aquaculture. A detailed TA indicated that the benefits of the proposed IWBF would, at the majority of sample sites, outweigh the potential negative impacts and it was thus recommended that investigations should continue on pilot-scale facilities. Furthermore, although the proposed TA based on four sustainability criteria categories was thought to provide a more accurate assessment of the true sustainability of a technology, the acquisition of information was problematic highlighting the need to re-think current TA methodologies and to address associated constraints allowing the tool to be used and fully comprehensive.

M.Sc. (Chemistry) / Prosperity for South Africa depends on the sound management and utilization of many resources, with water playing a crucial role. Located largely in a semi-arid part of the world, South Africa’s water resources are, in global terms, scarce and extremely limited. A key environmental problem facing South Africa is water pollution. This arises from many sources, including mining and industrial effluents, and runoff of biocides, nutrients and pathogens from agricultural lands, urban areas and informal settlements with poor sanitation. The consequences are often severe, including among other impacts, habitat destruction, reduced oxygen levels, fish kills and loss of human life. Inorganic and organic pollutants as well as microbes are the main constituents of the effluent from the domestic, mining, agriculture, metal electroplating, petrochemical and transport industries. The presence of pollutants in environmental systems is of concern because ultimately, they are incorporated into drinking water and various food chains. Therefore, the overall focus of this study was mainly metals analysis in wastewater systems before and after treatment processes so as to establish the efficiency of the treatment processes....

Submitted in fulfillment of the requirements of the Degree of Master of Technology: Chemistry, Durban University of Technology, 2014. / This project arose out the need for a simple method to analyse NOM on a routine basis. Water samples were obtained from the Vaal dam, which is one of the dams used by a hydroelectric power station. Analysis was preceded by separation of NOM into the humic and non-humic portions. The humic portion was separated into two fractions by employing a non-ionic resin (DAX-8) to separate humic acid from fulvic acid. High performance size exclusion chromatography (HPSEC), equipped with an Ultraviolet( UV) detector and an Evaporative Light Scattering (ELS) detector connected in series, was used to obtain molecular weight distribution information and the concentration levels of the two acids. Mixed standards of polyethylene oxide/glycol were employed to calibrate the selected column. Suwanee River humic acid standard was used as a certified reference material. The molecular weight distributions (MWDs) of the isolated fractions of humic and fulvic acids were determined with ELSD detection as weight-average (Mw), number-average (Mn) and polydispersity (ρ) of individual NOM fractions. The Mw/Mn ratio was found to be less than 1.5 in all the fractions, indicating that they have a low and narrow size fraction. An increase in Mn and Mw values, with increasing wavelength for all three humic substances (HS) examined was observed. The HS, isolated from the dam water, was found to be about the same molecular weight as the International Humic Acid Standard (IIHSS). For the fulvic acid standard, the molecular weight was estimated to be around 7500 Da. Characterization of NOM was done to assist in the identification of the species present in the water. FTIR-ATR was used to as a characterization tool to identify the functional groups in the structure of the humic and fulvic acid respectively present in the Vaal Dam. Analysis of the infrared (IR) spectra indicated that the humic acids of the Vaal dam have phenolic hydroxyl groups, hydroxyl groups, conjugated double bond of aromatic family (C=C), and free carboxyl groups. The isolation method has proved to be applicable and reliable for dam water samples and showed to successfully separate the humic substances from water and further separate the humic substances into its hydrophobic acids, namely, humic and fulvic acids. It can be concluded that the Eskom Vaal dam composes of humic substance which shows that the technique alone gives a very good indication of the characteristics of water. The HPSEC method used, equipped with UV and ELSD was able to identify the molecular weight range of NOM present in source water as it confirmed that the Eskom Vaal dam contains humic substances as humic acid and fulvic acid and these pose a health concern as they can form disinfectant byproducts in the course of water treatment with chemicals. FTIR characterization was successful as important functional groups were clearly assigned. Lastly, the use of the TOC and DOC values to calculate SUVA was also a good tool to indicate the organic content in water. It is recommended to use larger amounts of water must be processed to obtain useful quantities of the humic and fulvic acid fractions.

Water quality from surface sources is fast deteriorating due to pollution from organic compounds. Among the organic compounds are chlorophenols, which are described as priority pollutants because of their detrimental effects. One way of removing them from water is by using membranes. However direct removal of chlorophenols using membranes is limited due to the inherent problem of membrane fouling. The thesis describes fabrication of thin film composite membranes modified with Ag-TiO2 and Ag-ZnO for enhancing filtration properties of the membranes for removal of 2-CP and 2,4-DCP and improving the antifouling properties of the modified membranes. Chlorophenols, 2- CP, 2,4-DCP and 2, 4, 6-TCP were determined from Vaal and Klip River using SPE- HLPC method. The SPE - HPLC method was validated by determining breakthrough volume, repeatability, reproducibility, linearity, MDL and LOQ. Nanoparticles (NPs), Ag, ZnO and TiO2 and nanocomposites (NCs), Ag-TiO2 and Ag-ZnO were synthesized using precipitation method and chemical reduction for Ag. The NPs and NCs were characterised using UV-Vis, FTIR, XRD, SEM and EDX. The synthesised NPs and NCS were evaluated for photocatalytic degradation of 2-CP and 2,4-DCP, antimicrobial activity against E.coli. and toxicity against Daphnia magna. Nanocomposites were then embedded into the PA thin film membrane surface using interfacial polymerisation and PES as a support material to produce the antifouling Ag-TiO2/PA-TFC and Ag-ZnO/PA-TFC membranes. The control PATFC membrane was prepared with no added NCs to the membrane. The membranes were characterised using ATR-FTIR, contact angle, SEM and AFM. The performance of the membranes was tested using permeation flux (using pure water and 2-CP / 2,4-DCP solutions as feed) against the neat PA-TFC membrane. Membranes were further tested for rejection of 2- CP and 2, 4 – DCP, antifouling properties and flux recoveries. The stability of the antifouling properties of the membrane was evaluated through silver release test. The performance of the membranes was tested using real water samples from Vaal and Klip Rivers. The SPE-HPLC method was repeatable, reproducible with % RSD less than 5%. Linearity range of (0.1-50 µg/ L) and recoveries of spiked water samples of more than 97% for 2-CP and 2,4-DCP but lower at 64 and 75% for 2.4.6-TCP were achieved. The Ag, TiO2 and ZnO NPs showed characteristic peaks of NPs with UV-Vis. The absorption peaks were all blue shifted due to quantum confinements. The crystalline structures were confirmed as face centred cubic, anatase and hexagonal wurzite for Ag, TiO2 and ZnO respectively. The morphology as observed from SEM showed spherically shaped nanoparticles with average sizes of 68.25 ± 4.7 and 50.92 ± 3.39 nm for Ag and TiO2 respectively. The ZnO NPs were rod -like shaped with average length = 603 nm ± 50.4 and a width = 82.92 ± 5. 40nm. Successful incorporation of silver into the TiO2 and ZnO structures was confirmed by elemental analysis, EDX. From SEM images, silver particles were distributed around TiO2 particles and ZnO rods. The presence of silver showed a remarkable improvement in photodegradation of 2-CP and 2,4-DCP from less than 40% to 86% with 2, 4- DCP. Silver modified TiO2 and ZnO showed antibacterial activity against E.coli. with minimum concentration of inhibition as low as 1.56 mg/L for both Ag-ZnO (5) and Ag-TiO2 (5). Silver was more toxic against Daphnia magna than Ag-ZnO (5) and AgTiO2 (5). The polyamide layer was confirmed by the presence of the amide I peak at 1650 cm1 and 1670 cm-1 in the Ag-TiO2/ PA-TFC and Ag-ZnO/ PA-TFC membranes. The appearance of NCs particles spread across the surface of the thin layer of the membranes as observed from surface SEM images confirming their incorporation into the PA layer. The presence of the NCs in the membranes improved water flux, water permeation, rejection of 2- CP, and 2,4-DCP, antifouling properties of the membranes and flux recoveries of more than 93 % was achieved. Silver release test revealed that Ag-ZnO/PA-TFC membrane performed better than AgTiO2/PA-TFC membrane because of the steady release of silver, which shows long lasting antifouling properties. When applied to real water samples from Vaal and Klip River, the prepared membranes showed better antifouling properties than the neat PA-TFC membrane

South Africa is facing numerous challenges that pertain to increasing water deficit and pollution of water resources. Only 40 out of 821 wastewater treatment works in South Africa achieved Green Drop certifications in the 2010 Green Drop assessments (DWA, 2011). This is not only threatening net water availability but also human health. South African water sources are comprised of 77 % surface water, 14 % return flows and 9 % groundwater (van Vuuren, 2009). This study was therefore intended to explore the quality, quantity and treatability of corn wet milling effluent resulting from Tongaat Hulett Starch Pty Ltd (THS) operations. THS is a major producer of corn derived starch and glucose in Africa. Amongst its three corn wet milling plants in Gauteng (Kliprivier, Germiston and Meyerton) and one in Western Cape (Bellville), 600000 tonnes of maize were processed in the 2011/2012 financial year. The objective of the study was to establish the wastewater footprint of the corn wet milling process. To achieve this, qualitative and quantitative characterisation studies were completed on effluents generated from the Germiston and Meyerton corn wet milling plants, respectively. This characterisation study was focused on volumetric and organic load analyses of the various sections of the corn wet milling process. A full scale anaerobic digestion treatability study of the Meyerton plant effluent was also conducted. The study results indicated that the combined effluent discharged to the Municipal sewer averaged between 2.9 and 3.1 m3/tonne of corn processed. The effluent generated resulted in an average chemical oxygen demand (COD) concentrations of between 6211 and 7790 mg/L, with suspended solid concentrations of between 635 and 899 mg/L. From the full scale anaerobic treatability study, a minimum of 87 % COD removal at organic volumetric loading rates (OLR) of between 0.3 and 3.9 kg COD/m3.d was achieved. It was concluded that corn wet milling effluent can be categorised as high strength in terms of COD concentrations. This type of effluent proved to be amenable to anaerobic digestion treatment. Anaerobic pretreatment of corn wet milling effluent can proportionately reduce pollution loading into the receiving municipal conventional wastewater treatment systems. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2013.

PUMPS mimics natural geothermal vents as a conceptual model designed for the remediation of acid mine water (AMW) in voids of abandoned gold mines of the Witwatersrand Basin in South Africa. In this system, a reaction chamber containing Desulfotomaculum kuznetsovii sulfate reducing bacteria will be set at the bottom of a 3-4 km deep mine that will be flooded. A geothermal system with at least one (1) doublet will be drilled from the bottom of the mine to the depth of 8km, where the temperatures are sufficient for geothermal energy harvesting. AMW, used as a geothermal fluid, will be pumped down the injection well and circulate through hot rock. The hot water is then used to generate electricity and then channelled into the reaction chamber to undergo bio-remediation. Following treatment, the water flows back into the mine voids where it will improve the quality of untreated AMW through dilution. Eventually, the mine will be flooded with clean water that can be stored underground and/or pumped up to surface for social and ecosystem services. Following an introduction and proof of concept for the PUMPS, the research builds further on the technical and economic evaluation of the PUMPS in order to assert its viability and sustainability. The technical viability includes testing the ability for Desulfotomaculum kuznetsovii to survive in high pressure condition; quantifying the amount of energy that can be drawn from the geothermal reservoir; determining the placement and scheme of the geothermal wells; and, finally, developing a robust economic model of the system. Experiments show that Desulfotomaculum Kuznetsovii can tolerate high pressure conditions in of at least 100bar at their ideal sulfate reducing temperature of 63°C. Geochemical modelling shows that AMW can be used effectively as a geothermal fluid for PUMPS. To achieve highest efficiency and minimal fluid loss, the geothermal wells should be placed along the SSE-NNW direction, based on the known stress field across the Witwatersrand Basin. With a flow rate of 30l/s the energy drawn from the geothermal reservoir is sufficient to drive PUMPS and the surplus energy is determined by the volume of AMW treated per day. All results indicate that the PUMPS is technically and economically viable. The economic model shows that the value and viability of the PUMPS is best reflected with a comprehensive inclusion of potential revenue (for example from chemical solution mining of deep seated gold) and financial/environmental incentives.

Submitted in fulfillment of the requirements for the degree of Master of Engineering, Department of Industrial Engineering, Durban University of Technology, Durban, South Africa, 2017. / Access to clean and adequate water is a universal and basic human right that feeds into the 6th of the 17 Sustainable Development Goals (SDGs). This goal aims at ensuring availability and sustainable management of water and sanitation for all. Clean water is referred to as potable water, which is safe for human consumption and offer low risk of immediate or long term harm. Raw water undergoes rigorous processing which consists of coagulation, sedimentation, filtration, disinfection and storage, to produce potable water. Each module or stage consumes chemicals and energy resources and thus incurs costs. To achieve the aim of the study, which was to synthesize an optimised potable water treatment network and a water usage analysis model, the Umzinto Water Treatment Plant (UWTP) and its distribution system was used as the study area. This treatment plant is located within Umdoni, a local municipality of the Ugu District Municipality in KwaZulu-Natal Province, South Africa. This study’s objectives were fourfold and the first objective was to identify and quantify key raw water quality parameters affecting treatment at the UWTP. The second objective was to design a genetic algorithm for the potable water treatment process control. The third objective was to evaluate the Umzinto Water Distribution System’s Non-Revenue Water (NRW) while the fourth objective was to develop a model for water usage analysis. For the first objective, data for water quality parameters for the water treatment from July 2006 to June 2013 were statistically analysed. This data were collected from the UWTP’s historical records. To improve the data’s integrity it was pre-processed using cubic hermite interpolation. After the pre-processing trend lines and box plots were used to determine the parameters’ significance compared to the standard values stipulated in the South African National Standard (SANS 241). The trend lines were used to analyse the frequency of observations that were higher than the standard values according to SANS 241. The box plots were used to determine the minimum, median, maximum and mean of the data sets. The mean values for each parameter were compared to the SANS 241 value to determine their significance. The raw water quality parameters were then correlated to the chemical dosages for lime, polymer, potassium permanganate and chlorine. The key parameters selected from the correlation analysis were algal count, manganese (Mn), iron (Fe), Escherichia coli, total coliforms, colour, odour, conductivity, turbidity, suspended solids (SS), pH, temperature, total organic carbon (TOC,) and Hardness. A number of methods can be used to achieve such optimisation, including artificial neural networks, dynamic programming, linear and non-linear programming, and this study utilised a genetic algorithm as an optimisation tool to achieve the second objective of optimising water treatment at the UWTP. For the model development, data from the correlations obtained for objective 1 were used. The model was aimed at reducing the cost of chemical dosage and four chemical dosage prediction models were developed using genetic algorithms and these were then used to produce a combined chemical dosage cost prediction model. The programming interface utilised for these models was Matlab. In developing these models, the data were first pre-processed to remove outliers and fill in the blanks using a Microsoft Excel Add-in that was developed for this particular purpose. The next step involved a curve fitting exercise in Microsoft Excel 2013. Matlab was then used to code the genetic algorithm that combined and optimised the solutions obtained from the curve fittings. The results showed that genetic algorithms can be reliably used to predict the chemical dosages and hence reduce water treatment costs. After treatment, water is pumped into the distribution system for consumption. It is therefore important to ensure that all the pumped out treated water reaches the consumer. The third objective therefore assessed the NRW for the Umzinto Water Distribution System for the period between July 2013 and June 2014. The data used for this objective was provided by the Ugu District Municipality. The method used combined the top-down approach and the component-based approach. This combined approach was modified to enable the calculation of all the components that are required in a standard South African Water Balance. The results showed that the distribution system had a high value of NRW, which was 27.9% of the System Input Volume. The major component of NRW was Real Losses, that is, losses that can be mitigated by improving maintenance. The fourth objective was to develop a model for water usage analysis that would reduce the time taken to evaluate NRW and also improve the analysis of the NRW components using Microsoft Visual Basics 2012 and Microsoft SQL Server 2012 development interfaces. The Visual Basics enabled the development of a graphic user interface that was user-friendly and minimised the time taken to learn the software. The software platform developed was able to import the data required to construct a standard International Water Asssociation (IWA) Water Balance, calculate all the components of NRW, store historical data for the water distribution systems and report on a rolling year basis. A model for water usage analysis was developed and made available for usage by practitioners in Ugu District. The model was developed for the specific study area and further studies would be required in order to validate it in a different setting. The results obtained for the first objective led to the conclusion that, there was very high pollution emanating from communities and activities close to the raw water sources, especially the EJ Smith Dam. The results from the first objective were also used to determine parameters for the models developed in the second objective. From objective two it was concluded that genetic algorithms can be reliably used to predict chemical dosages and hence reduce water treatment costs. The third objective’s results showed that 27.9% of treated water pumped into the distribution system is NRW. Which is a concern because 65% of this are real losses which have maintenance related problems. The fourth objective’s results showed the practicality of designing model that could be used determine all the important components of NRW that would take time to evaluate manually. It would also store historical data for the water distribution system and report on a rolling year basis. Implementation of this software would help minimise the errors associated with manual calculation of NRW and improve the availability of data for research and analysis. From the research findings, it is recommended that the treatment plant should change the way it is dosing chemicals in the balancing tank. The method currently being used is prone to error. The analysis of NRW showed that Real Losses were a major challenge in the Umzinto Distribution System. There is need to develop a maintenance program to cater for leakage. Communities also need to be educated on the importance of reporting leakage in the network. / M

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

Thesis (M.Sc. (Microbiology)) -- University of Limpopo, 2016 / Access to safe drinking water is a major problem globally and it mostly affects people living in low-income countries. The lack of potable water leads to the use of raw water from surface or ground water sources for drinking and other household purposes. A water filtration unit was designed and constructed using fabric, gravel and sand, which were wet-packaged into a 20 L bucket. The efficiency of the filter unit to improve the bio-physicochemical properties of contaminated water was tested using surface waters from rivers in the Sekhukhune area. Physico-chemical parameters tested included turbidity, colour, total suspended solids (TSS), total dissolved solids (TDS), total hardness and pH. Turbidity and colour were the most improved characteristics, where turbidity improved by 69% and colour by 80%. Other parameters such as total hardness, TSS and TDS were non-significantly reduced following treatment with the filtration unit. The amount of soluble solids in raw water was well within allowable limits by WHO standards. Microbiological tests included heterotrophic bacteria, total coliform and faecal coliform counts. The bacterial load was too numerous to count for the untreated water, however, after treatment with the filtration unit, heterotrophic bacterial load decreased to 15 x 10103 CFU/ml, total coliforms to 14 x 10 2 CFU/100ml and faecal coliforms to 11 x 10 2 CFU/100ml. Further treatment with UV sterilization unit resulted in undetectable amount of bacteria. The unit designed in this study can be beneficial in those rural communities were clean water is not available, it is easy to construct and simple to operate and most importantly it reduced contaminants in surface water. The UV unit incorporated in this study is not cost effective, therefore, other household treatment options such as chlorination and boiling which are easily accessible to most communities can be used to further eliminate remaining microorganisms after filtration. The effective shortest boiling time and minimum dosage of Na(OCl2) have been previously tested in our laboratory and total elimination of bacteria was achieved within 2 minutes of rolling boil and after 30 minutes following addition of 5ml/20L of liquid chlorine.