Engineering and the Built Environment Departments

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    Impact of vegetation clearance on the hydrology of Luvuvhu River Basin in Soutpansberg area using Working for Water as a case study
    (2010-08) Maumela, Azwihangwisi Doris; Odiyo, J. O.
    This dissertation focuses on the impact of vegetation clearance on hydrology of Luvuvhu River using Working for Water as a case study. Working for Water Programme (WFW) is a multi-departmental initiative led by the Department of Water Affairs and Forestry and its main aim is enhancement of water security by clearing alien vegetation. Alien vegetations are plants that do not occur naturally in an area and many are classified as weeds. Invasive alien species, particularly tree species, often have increased water usage compared with native vegetation, especially where the latter is short. The study examines how increased water use by alien tree species impact on the hydrology of a river basin. The study attempts to determine the impacts of alien vegetation on hydrology by analyzing temporal hydrological trends up to 1995 and after 1995 when Working for Water Programme was initiated. Rainfall data, stream flow data and evaporation data have been used in the analysis of temporal trends before and after the working for water programme started their alien vegetation clearance activities. Standardized Precipitation Index (SPI) was used to analyse the rainfall data. This involved computing the SPI values for the rainfall time series data. Flow duration curves were used to determine the percentage of time flows stays in the river and changes in flow magnitudes. The results of the study though determined from the limited hydrological data sets available indicated that the changes in stream flow were due to alien vegetation clearance and global warming. The study recommends improvement in monitoring the hydrological components in order to have accurate, reliable and continuous information that can be used to determine the hydrological impacts associated with alien vegetation.
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    Community management of wetland ecology and socio-economic costs of wetland degradation in mudaswali Wetland, Limpopo Province, South Africa
    (2010-09) Sinyati, Mollel; Omara-Ojungu, P. H.
    Wetlands are one of the most degraded ecosystems on the earth's surface. In South Africa, loss and degradation of wetland ecosystems have occurred particularly through a variety of human activities. This loss of value of wetlands have impacts on functions such as water purification, flood control, ground water recharge/discharge, sediment/pollutant and nutrient retention which have serious consequences on socio-economic benefits of wetlands. However, there is still little knowledge amongst the local communities of what wetland degradation costs them. This study therefore, explores ways in which local communities value and engages in the management of wetlands by quantifying and costing (in financial terms) wetland degradation vis-a-vis socio­ economic costs. Judgemental assessment method was used to select the site for observations and availability of respondents. A structured questionnaire with open and closed ended questions was administered to 65 respondents who reside in the vicinity of the Mudaswali wetland. Focus group discussion helped to provide a technical perspective on the quantum of each wetland value and the estimate of wetland degradation in the region. Willingness to accept (WTA) technique was used to facilitate the estimate of socio-economic costs of wetland degradation by the local community. In addition, the use of willingness to pay (WTP) method helped in determining the value of wetland in the local community. As part of the major findings of this study, the majority of the respondents were females in the study. The most frequently stated value of the wetland resource was water for household consumption, land for cultivation; and fibre for handcraft and construction materials for example; clay and reeds used for thatching/roofing houses. A total of 51% of the respondents stated the degradation of wetlands in the area is between 51-80% (that is; significant). The results of respondents' willingness to accept (WTA) compensation for degradation and loss of wetland was a sum of R390 per month. Given the relatively low level of income (R500-R800) within the community, a loss of R390 constitutes a drawback to the community. On average, the respondents' willingness to pay (WTP) for wetland conservation was a sum of R30 per month. It should be noted that earlier the cost of wetland degradation to the community as a whole was estimated at R390 per month. The suggested value (R30) for conservation is therefore a strong expression for the value of wetlands to the individuals in the community. This research recommends the empowerment of local community using various incentives to encourage them to participate in conserving and managing the wetlands. There is also a need to carrying out further research on the proper utilization of wetlands and monitoring of wetland uses at local community scale.
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    Mineralogy, geochemistry and health impacts of earth materials consumed by humans in Vhembe District, Limpopo Province, South Africa
    (2013-09-17) Momoh, Abhuh; Davies, T. C.; Akinsola, H. A.
    This work focuses on three main themes (clay mineralogy and geochemistry, bioaccessibility of essential nutrients and effects of eating Earth materials on human health), treated in five chapters. The first theme of the study assessed the prevalence of geophagic practice in the area. Issues examined were demography, rationale for eating Earth materials or dirt and distribution chain of consumed Earth material in the District. Purposive sampling was used to identify 438 women who practice geophagy in the area. Forty six point three percent of the women were married, 45.4% were single, 4.3% were divorced and 3.2% were widowed. The reasons they gave for geophagic practice are medicinal, quelling of nauseate feelings and control of early morning sickness in pregnancy. Clays aad soft stone are the most preferred types of Earth material. Average daily ingestion rate for pregnant women was 90 g per day while non- pregnant women consume an average of 40 to 60 g on a daily basis. Features of geophagic materials were assessed with a view to ascertain if these features could assist in the understanding of these geophagic materials to perform some of the functions that have been adjudged for human geophagic practice. Tests conducted include: colour, pH, electrical conductivity (EC), cation exchange capacity (CEC), textures and occurrence of beneficial bacteria in the samples. Colour ranged from red, yellow to dark grey through various shades of brown. The pH of the geophagic materials ranges from 4.30 to I· 7.90. The values obtained for EC ranges from 8.22 µSiem to 652 µSiem while CEC ranges from 3.74 meq/l0Og to 19.78 meq/l00g. On the basis of texture, the consumed Earth materials were classified as clays, sandy clay loam and silty clay materials. Significant growths of filamentous bacteria (Streptomycete) were recorded in some geophagic mate1ials from the District. Aggregates of grey, brown and whitish bacteria colonies were observed on the rim of the plates. The third part of the study focused on an investigation of the potential of these geophagic materials to supplement the mineral nutrients of geophagists. The oral bioaccessibility using in vitro physiologically based extraction test (PBET) was used. A simplified, two-stage extraction simulating the human stomach (pH 1.2 - 1.7) and intestine (pH 6.3 - 6.5) was developed and applied to 30 geophagic samples. Extractants were analysed by inductively coupled plasma mass spectrometry (ICP-MS). The element concentrations extracted from geophagic materials within the human stomach and intestine respectively were on average 0.90 and 0.20 ppm Fe; 81.44 and 22.42 ppm Zn; 10.10 and 9.02 ppm Se; 1672.7 and 1900 ppm Mn; 24.93 and 230.04 ppm Cu; 11.73 and 11.72 ppm Co; 2.22 and 3.23 ppm As; 29.50 and 35.91 ppm V; 5.59 and 102.87 ppm Cr; 5.53 and 21.28 ppm Ni; 0.09 and 0.05 ppm Cd; 5.52 and 6.72 ppm Pb. Iron, Zn, Mn and Cd bioaccessibilities were found to be higher in the stomach while Cu, V, Cr, Ni, Hg and Pb bioaccessibilities were found to be higher in the intestinal phase. Bioaccessibilities of Se, Co and As were similar in the stomach and intestinal phases. The fourth aspect of this study focuses on the implications of eating Earth on human health in Vhembe District. Haemoglobin levels in blood of non-pregnant geophagic women were measured and identification of helminth ova in 30 geophagic samples and 3 non-geophagic samples were investigated to confirm the possible role of geophagy in causing iron deficiency anaemia and in the transmission of geohelminths (Ascaris lumbricoides, Trichuris trichuria, Stongyloides stercoralis and Hookworm). Sixty eight non­ pregnant geophagic women between the ages of 18 and 49 and five non-pregnant women that do not practice geophagia between the ages of 18 and 45 (control group) were recrnited into the study. Forty four percent of the geophagic women were diagnosed as anaemic and 56% were normal. All the women in the control group were normal. An Ascaris lumbricoides ovum was detected in sample 21 of the geophagic material. The fifth aspect deals with determination of minerals in consumed Earth materials. Thirty five samples of consumed Earth materials and three non-geophagic clays were analysed for their mineralogical composition using x-ray diffractometer (XRD). The concentrations of major and trace elements were determined by means of x-ray fluorescence spectrometry (XRFS). The clay mineralogy showed that consumed Earth materials consist of kaolinite, smectite, muscovite, quartz, albite, orthoclase, goethite, hematite, microcline and anatase. Result of Tukey's post hoc test mineralogy showed that only kaolinite has a significant percentage with respect to all other minerals. The consumed Earth materials are richer in kaolinite (samples 1, 4, 7-9, 11-23, 24-30) with a lesser percentage of quartz than non­ consumed Earth materials. Major element chemistry of the consumed Earth materials are enriched in Fe and Al and depleted in Ca, K and Mn. The chemical index of alteration (CIA, concentration of elements in soils and rocks) for the consumed Earth materials ranges from 17.09 - 99.07. Kaolin is the dominant mineral in the consumed Earth material; and because of its ability to coat and adhere to intestinal membrane of geophagist, this could suggest that pregnant women, lactating mothers and children indulge in geophagic practice to seek various fo1ms of protection against gastrointestinal problems and toxins.
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    Development of a modeling framework for design of low-cost and appropriate rehabilitation strategies for Nyala abandoned mine
    (2013-10-01) Mhlongo, Sphiwe Emmauel; Amponsah-Dacosta, F.; Mphephu, N. F.
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    Investigation into the success and failures of Integrated Development Plans (IDPs) as a service delivery tool in Makhado Local Municipality
    (2014-01-10) Ngobeni, Thandeka Venus; Bikam, P.
    Integrated Development Plans were made a legal requirement for municipalities in the Local Government Transition Act: Second Amendment Act, 97 of 1996, their conceptualization at a policy level was very limited. Thus, the requirements for IDP overlap to some extent with the planning requirements of the Land Development Objectives (LDOs) as established by the Development Facilitation Act, 67 of 1995. It has emerged as one of South Africa's development magic bullet that strives to overcome a number of development anomalies created during the apartheid era. Basic service and infrastructure delivery is one of the issues which an IDP has to address as required by the legislation. Some of the problems related to the IDP is not meeting the targets set in the IDP, with respect to service delivery and whether outputs are achieved, whether standards met, performances monitored, measured and evaluated and whether the IDP is credible in the first place. This study investigates the level of the success or failure of Makhado local municipality in attaining the Millennium Development Goal (MDG) in terms of the implementation of >- the IDP to achieve the service delivery targets. The discussion focuses on the success or failures in relation to the framework provided in the IDP in relation to service delivery issues and the credibility of the IDP in the six Key Performance Indicators. We have assessed Makhado local municipality IDPs from a base year of 2008 to determine whether services delivery projects listed in those IDP were successfully implemented or not. In terms of service delivery projects in Makhado's IDP the analysis shows that some projects were carried out successfully while others are not successful delivered. The failures were due to lack of funds and budget, political intervention; corruption by private service provides executing projects and change of priorities. Other service delivery projects were just wish list in these IDP without budget and some projects were replaced by others, without concerns to the local needs of the communities. The study suggests a number of measures and recommendation in chapter six of the report to address the challenges at a global and at the municipal level.
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    Characterization of potential acid leachate from raw coal, discard coal and slimes from Mafube Colliery : a replication to a proposed new extension, Mpumalanga Province, South Africa
    (2014-01-10) Novhe, Ntshengedzeni Obed; Ogola, J. S.; Maree, J. P.
    Anglo Coal and Eyisizwe Coal plan to extend mining activities at the Mafube Colliery, Springboklaagte, Arnot North coal reserves. However, an integral part in every mining development project is the consideration of environmental impacts, particularly, the generation of acid mine drainage. Integrated geochemical and mineralogical study was conducted on raw coal, discard coal and slimes from the Mafube Colliery, to characterize the potential of acid leachate and also to quantify the quality of leachate from the samples. Bulk chemical and mineralogical analyses were done by means of X-ray fluorescence spectrometry and X-ray diffraction. Total sulphur and carbon content were determined by means of LECO induction furnace. Raw coal was found to contain 0.4% of sulphide sulphur, predominantly as pyrite; 27% quartz and 73% kaolinite. Discard coal was found to contain 5% of sulphide sulphur as pyrite, and up to 80% of clay minerals such as kaolinite, as well as quartz and calcite (1%). Furthermore, raw coal contained 62% of carbon, whereas discard coal had only 29% carbon. Static tests were performed by means of acid base accounting procedures (ASA) to measure the theoretical potential of samples to generate and consume acid. Raw coal and slimes were found to be potential non­ acid producers (raw coal NNP=13.7 kg CaCOiton and slimes NNP=8.9 kg CaCOiton); whereas discard coal was found to have potential to produce acid (NNP= -12.2 kg CaCOiton). Column leaching tests were also carried out on samples using both tap water and pit water to determine the chemistry of leachate from samples over a period of time. Raw coal and slimes produced neutral leachate (raw coal pH=6.11 to 7.16 and slimes leachate pH=7.12), whereas discard coal produced acidic leachate (pH=2.86). Discard leachate was found to be characterized by two stages; the initial rapid acid generation stage followed by cyclic buffering due to dissolution of calcite, and possibly by less reactive kaolinite, and mica. This study has identified potential risks of acid generation from the future discard coal dump and recommendations were made to ensure that appropriate measures to prevent pollution into the environment are developed and implemented.
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    Investigation of coagulant properties and efficiency of Diceriocaryum Eriocarpum Plant for turbidity removal and biosorbent for heavy metals uptake in aqueous solution
    (2015-07-23) Bassey, Odo James; Odiyo, J. O.; Aoyi, O.; Chimuka, L.
    Environmental pollution over the past decades has reached crisis level due to the nature of pollutants that leach into the water bodies. Inadequate water services coupled with lack of potable drinking water infrastructure is one of the major challenges facing most of the rural communities in South Africa. This research was aimed at investigating the potential of a new and cost effective plant material as biosorbent in the removal of heavy metal ions from aqueous solution and also as coagulant for removal of turbidity from raw water. The material is intended for use in rural households where most of the domestic water supplies are untreated. Therefore, this study proposed the use of mucilage from Diceriocaryum eriocarpum (DE) as biosorbent in the removal of heavy metals from aqueous solution and as coagulant in the removal of turbidity from raw water. To this end, modification of the DE mucilage was carried out by addition of chlorides during the extraction process. Extraction of the mucilage was carried out using KCl, NaCl solution and deionized water solely. Characterisation of the active agent in the mucilage was carried out using Fourier transform infared spectroscopy (FTIR). Improvement of the coagulation efficiency was carried out by optimizing various parameters. Assessing the biosorption capability of DE mucilage was also achieved by optimizing parameters. Optimization was achieved by varying one parameter while keeping the others constant. Application and improvement of coagulation and biosorption potential of DE was greatly attributed to the functional group (active agent) present in the mucilage. FTIR results showed that the functional groups acting as the active agent in DE both in modified and unmodified mucilage were carboxyl, hydroxyl and carbonyl groups. The chloride used in the modification of the mucilage did not introduce new functional groups but rather expanded and increased the already existing functional groups in the mucilage. The modified mucilage: potassium crude extract (PCE) and sodium crude extract (SCE) display high coagulation and biosorption efficiency more than unmodified mucilage; deionized water crude extract (DCE). It was observed that an increase in coagulant dosage, settling time and initial turbidity influence the coagulation efficiency of DE mucilage. Assessing the EC-levels, pH and high reduction in turbidity levels of the treated water samples showed that the treated water was of high quality. Coagulation mechanism for unmodified mucilage was suggested to be strong repulsion force while modified mucilage mechanisms occur via double layer interaction and charge neutralization. Results from biosorption experiment showed that, DCE, SCE and PCE display good binding affinity with heavy metal ions (Zn, Cd, Ni, Cr and Fe) in the aqueous solution. It was also observed that an increase in the aqueous solution pH, mucilage concentration and initial concentration of metal ions also increased the sorption efficiency of DCE mucilage. The DCE biosorbent was able to attain equilibrium rapidly within 8-10 minutes of contact time. Biosorption mechanism for both modified and unmodified mucilage seems to occur via electrostatic interaction and binding chelation. Generally, it was observed that the modified mucilage was highly efficient in turbidity removal and also in the removal of metal ions more than the unmodified mucilage. This can be attributed to the presence of the salts enhancing the mechanism in the active agent (functional groups) of DE coagulant. Hence, the best method for improving the coagulation and biosorption efficiency of DE plant is by using salt solution in extracting the mucilage. Coagulation efficiency was improved to 99% using modified mucilage coagulant. In light of this, the adoption of DE mucilage in treatment of raw water showed good results and can be adopted for household use in communities where there is need for potable drinking water.
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    Trace element concentrations in geothermal springs and their impact on soil and vegetation in Siloam and Tshipise
    (2015-10-20) Durowoju, Olatunde Samod; Odiyo, J. O.; Ekosse, G. E.
    ABSTRACT Siloam and Tshipise Springs are scalding geothermal springs geologically located within the Soutpansberg Group in the Limpopo Province of South Africa. These geothermal springs are associated with faults and impermeable dykes and are assumed to be of meteoric origin. The optimal use of a geothermal spring largely depends upon its physical and chemical properties as well as the geological controls at source and surrounding pathway to the surface. This study aimed at investigating trace element concentrations in these geothermal springs in order to quantify their impacts on neighbouring soil and vegetation. Impact on vegetation was assessed by incorporating seasonal variations of the trace element mobility from the geothermal springs to the vegetation (Mangifera indica at Siloam and Acacia robusta at Tshipise) via soil. The geothermal spring water, soil and vegetation samples at both sites were collected from May – July (winter) and September – November (summer), 2014. The soil samples were collected at 5 m intervals up to 20 m away from the geothermal spring in each of the sites. The bark and leaf parts of the vegetation were sampled. The control samples for water, soil and vegetation were obtained from Riverside residence at University of Venda, Thohoyandou, Limpopo Province, where there is non-geothermal source of water. The temperature, electrical conductivity (EC), pH and total dissolved solid (TDS) of the geothermal spring water and control samples were determined in situ and in the laboratory. The water samples were acidified for major cations and trace elements determination. There were also non-acidified water samples for major anion analyses. The soil and vegetation samples were digested using microwave and hot block methods, respectively. Concentrations of arsenic (As), antimony (Sb), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), mercury (Hg), lanthanum (La), lead (Pb), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), tin (Sn), strontium (Sr), tellurium (Te), thallium (Tl), titanium (Ti), tungsten (W), vanadium (V), and zinc (Zn) were determined by inductively coupled plasma – mass spectrometry (ICP-MS) (Agilent 7700 series). Concentrations of calcium (Ca), magnesium (Mg), sodium (Na) and potassium (K) were analysed using inductively coupled plasma – optical emission spectrometry (ICP-OES) (X – Series 2) whereas the concentrations of chloride (Cl-), fluoride (F-), nitrate (NO3-), phosphate (PO42-), bicarbonate (HCO3-) and sulphate (SO42-) were determined by ion chromatography (IC) (Dionex Model DX 500). Results from this study revealed that the geothermal springs were rich in trace elements compared to that from non-geothermal source of water. The mineral elements present were vii mainly due to rock-water interaction in the deep aquifer at both sites. The geothermal spring water is not fit for drinking because it is particularly high in fluoride (F) having 6.66 and 5.97 mg/L at Siloam ; 6.72 and 7.28 mg/L at Tshipise for winter and summer, respectively. Also, high Nickel (Ni) with 462 µg/L and 868 µg/L: Lead (Pb) with 652 µg/L and 211 µg/L at Siloam and Tshipise respectively, for summer season. In addition, it is not suitable for irrigation owing to high sodium absorption ratio (SAR) values which were above the standard guidelines (˂1) by South African Bureau of Standards (SABS) and World Health Organization (WHO) at both sites. In summer season, there were higher trace elements concentrations than in the winter season. The higher concentration values could be attributed to rainfall, which aids in the dissociation of rock particles, resulting in higher concentrations of these elements. Siloam spring water was more mineralised than Tshipise spring water, hence its neighbouring soils and vegetation possess more trace elements concentrations than the latter. Owing to their high mineral elements content, the geothermal spring water flows across the soil, making it vulnerable to sorption of the trace elements. The trace elements present in the surrounding soil of the geothermal spring were as a result of geothermal water and soil pedogenesis. The geothermal water contaminates the surrounding soil with substantial quantity of trace elements, which decreases with the distance from the geothermal spring, making far distanced soil less-contaminated. High levels of Cr, Co, Ni, Cu, Zn and Pb at Siloam soil can be attributed to more minerals present in the spring, therefore making absorption by Mangifera indica inevitable. Soils at Tshipise are moderately concentrated owing to moderate trace elements concentrations from the geothermal spring water. Generally, seasonal variations were observed in the parameters analysed in the geothermal spring water, surrounding soil and vegetation to ascertain the most favourable season in terms of the trace elements concentrations. There were higher concentrations of trace elements in the geothermal spring, particularly during the summer season, compared to the winter season; this leads to more contamination of the surrounding soils and vegetation. This study showed that geothermal spring has potential to enrich the neighbouring soils and vegetation with trace elements, which could result in contamination. It can be concluded that geothermal spring, despite its benefits to humans, also contaminates the surrounding surface soils with toxic trace elements. Soils are a platform for vegetation. Therefore, if the soil is contaminated by toxic elements, there are high possibilities that these trace elements are absorbed by the neighbouring vegetation, which is likely to affect human beings adversely.
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    An assessment of water quality of the wetland downstream of Makhado oxidation and its potential effects on irrigation waters
    (2016) Shibambu, C. S.; Gumbo, Jabulani; Gitari, W. M..; Pindihama, Glen
    Wetlands are known of their pollution reduction characteristics due to their flat topography and dense vegetation which capture pollutants on the settling sediments. Three processes take place on the captured pollutants in the sediments, the physical, chemical and biological processes, which facilitate the removal of pollutants from the wetlands. This research was carried out in order to assess the Water Quality of wetland downstream of Makhado oxidation ponds and its potential effects on Irrigation Waters by determining the Physical-chemical parameters (pH, Dissolved Oxygen, temperature, electrical conductivity and turbidity); the nutrient levels (Nitrates, phosphates, nitrites, bromide) and heavy metals. The water samples were collected from the effluent discharge of Makhado oxidation ponds (upstream), the middle section of the wetland (midstream) and downstream of the wetland. The climate data for the study was also used assess the contribution to variation in the physical-chemical parameters during their passage through the wetland. The use of waters in the wetland by subsistence farmer’s was also assessed to determine their farmer’s perception on wastewater reuse, sustainability, water quality, health hazards and crop yield. At the discharge and midstream point, the physical parameters tested were found to be mostly outside the target water quality range of irrigation water set out by DWAF but are within the DWAF guidelines for discharge of wastewater. The exceptions were with total dissolved solids which were higher than 25 mg/l guideline value of the said standards. The anions were analysed by Ion chromatography and showed spatial variation in content and seasonality. The nutrients (nitrates, nitrites and phosphates) and chloride were higher than the DWAF guidelines for discharge of wastewater. The heavy metal content in the wetland was analysed by ICP-OES and varied throughout the wetland. The following metals were reduced during their passage in wetland and were within DWAF guidelines: zinc, lead, cadmium and total chromium. Iron and manganese were reduced during the drier season but were above the DWAF guideline values during the wet season. Also the metal contents in the wetland are out of the target water quality range of the same standards bringing forth the risks of toxicity in the wetland. The anion analysis also suggests that the wetland is becoming a nutrient rich environment bringing forth risks of eutrophication. Nitrite concentrations did not conform to the South African viii Water Guidelines on target water quality ranges for irrigation water. Farmers have expressed a positive opinion on wastewater use for irrigation since there are loads of nutrients. The presence of nutrients in wetland may contribute to development of harmful algal blooms.
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    A study into the interaction of gold nanoparticles released into drinking water and wastewater system
    (2016) Raedani, Shumani Alfred; Gumbo, J. R.; Gitari, W. M.; Keter, Franklin K. K.
    This research involves the investigation of the interaction of different sized Nano Gold particles released into municipal drinking water and municipal waste water. Waste water was collected from Malamulele waste water treatment plant and the municipal water was collected at Mintek in Johannesburg, Randburg, South Africa. The waste water was analysed using ICP-MS to detect the metals and anions in it. The results showed the abundance of Sulphur (464 ppm), Calcium (28 ppm), Chloride (27.8 ppm), Iron (20 ppm), Magnesium (8.2 ppm), silicon (6.192 ppm) in descending order and other trace elements, including gold, that were immeasurable (<0.1). The simulated situation was created by adding 20nm gold and 40nm gold nanoparticles into municipal drinking water and waste water and kept at different environmental conditions (light, light and agitation, dark, dark and agitation) under aerobic and anaerobic conditions over a period of two months. Physico-chemical properties (pH and chemical oxygen demand) of the solutions were checked once in a month. The pH fluctuated between the acceptable ranges (5.5 – 9.5) for the two month period. Both municipal water and waste water, with and without gold nanoparticles, under aerobic condition showed an increase in chemical oxygen demand. The gold content in waste water under anaerobic condition showed an increase while under aerobic condition the decline in gold content was evident. The zeta potential of gold nanoparticles in waste water in light and agitation showed (-30 mV) while waste water on other environmental condition (light, dark and dark with agitation) presenting unstable (-18 mV) charge, but the charge shifted positively on the second month rendering them also unstable. Dynamic light scattering and TEM were used to check any possible aggregation or agglomeration of nanoparticles in the waste water. There were some few discrepancies where TEM and DLS contradict, but overall there was no significant probability of any aggregation of gold nanoparticles. The EDX was used to confirm the presence of Au0 in the waste water (with added gold nanoparticles). The research did show that the gold nanoparticles would exist as Au0 in the waste water and thus the discharge of Au-NPs to the sewer system is not recommended, but rather recycle them.
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