Thesis (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The Plankenbrug River runs past the dense settlement of Kayamandi, on the outskirts of Stellenbosch. This site was chosen to study the impact of water pollution from formal and informal urban developments on water quality and associated health factors. Aims of the study: (1) To determine some basic epidemiological characteristics of the exposed population of Kayamandi, their sanitation problems and reasons for poor hygiene; (2) To determine the microbiological and chemical pollution load patterns in the Plankenbrug River over time; (3) To investigate the spectrum of organisms present in the river (other than the indicator E. coli) and their epidemiological implications for health; (4) To establish the possible presence of organisms resistant to chlorine or to antibiotics in the river below Kayamandi as indicators of environmental hazard. Methods: During the period 5 May 1998 to 10 February 2003 microbiological and chemical analyses have been carried out every 6 weeks on water samples obtained at various points along the Plankenbrug River. Two large surveys (n=2196 persons and n=3568 persons) of the community of Kayamandi have been undertaken and door-to-door education campaigns were carried out with the aid of trained community health workers. Results: Below Kayamandi the river contains dangerously high levels of faecal contamination and it constitutes a health hazard to all persons coming into contact with the water. Up to 13 million Escherichia coli per 100 ml water was recorded (cut-off level as indicator of human safety is 1000 organisms per 100 ml water). Not all the faecal contamination originated from Kayamandi. Substantial amounts of faecal contamination sporadically entered the river at different points below Kayamandi. The pollution load resulting from these intrusions were sometimes larger than that contributed by the whole of Kayamandi. Water samples below Kayamandi were screened to ascertain what other pathogens were present. Amongst the organisms were 0 haemolytic Streptococcus Group A and B, Mycobacterium intracellulare, Staphylococcus spp, Klebsiella spp., Pseudomonas spp. and many others. The list of pathogens found had such serious implications that a confidential health warning was sent out to health care centres and other affected organisations in the area. |3 haemolytic Streptococcus Group A has never before been reported as isolated in viable form from free-flowing natural waters. Signs of increased resistance to chorine were found in organisms isolated from the river water. There were also organisms showing signs of resistance to commonly used antibiotics. The E. coli organisms that survived various levels of chlorine treatment also showed increased resistance to amoxycillin when compared to untreated E. coli organisms sampled from the Plankenbrug River. During the community phase of the project in Kayamandi a reduction in the pollution levels occurred over the summers of 2000 and 2001 (note that "improved" does not yet mean "safe" by any means). This can be ascribed to the multi-pronged approach of the project. Attention was given to service and repair of sanitation facilities, a strong accent on door-todoor community education about better sanitation behaviour, creation of a central reporting point for blockages and breakages, and training of artisans (plumbers, bricklayers, etc) from the community to help with upkeep. The community showed encouraging signs of wanting better sanitation education. The improvement in pollution levels is however in danger of reverting back to the previous dangerous situation if better support and co-operation cannot be obtained from the relevant authorities. There were 16.9% of households who reported one or more cases of diarrhoea during the survey period (5 weeks) - a very high prevalence seeing that the survey was carried out during a wet and cold winter period. Conclusions: Active planning and other steps to cope with the sewage intrusions into the river should be instituted without delay. The water quality of the Plankenbrug River downstream from Kayamandi is extremely poor. The water constitutes a serious health hazard and a threat to downstream economic activities. The settlement of Kayamandi demonstrated that education, when coupled with maintenance and repairs of existing toilet facilities, can bring about a reduction in pollution loads, but that this should be an ongoing process and not be reduced to sporadic attempts. / AFRIKAANSE OPSOMMING: Die Plankenbrug Rivier vloei verby die digbewoonde nedersetting van Kayamandi aan die buitewyke van Stellenbosch. Hierdie plek is gekies as studie-area om die impak te bestudeer van waterbesoedeling wat van formele en informele dorpsontwikkeling afkomstig is, asook die geassosieerde gesondheidsfaktore. Doel van die studie: (1) Om sommige basiese epidemiologiese eienskappe van die blootgestelde populasie, hulle sanitasieprobleme en redes vir die swak higiene te bepaal; (2) Om die mikrobiologiese en chemiese besoedelingspatrone in die Plankenbrug Rivier oor tyd te bepaal; (3) Om die spektrum van organismes teenwoordig in die rivier (anders as E. coli) te bepaal asook hulle epidemiologiese implikasies op gesondheid; (4) Om vas te stel, as indikatore van omgewingsgevaar, of daar moontlik organismes teenwoordig is wat weerstandig is teen chloriene en antibiotika in die rivier onder Kayamandi. Metodes: Gedurende die afgelope vier jaar is mikrobiologiese en chemiese ontledings elke 6 weke uitgevoer van watermonsters wat van verskeie punte op die Palnkenbrug Rivier verkry is. Twee groot opnames is in die gemeenskap van Kayamandi ondemeem (n=2196 persone en n=3568 persone) en deur-tot-deur opvoedingsveldtogte is uitgevoer met die hulp van plaaslik opgeleide gemeenskapsgesondheidswerkers. Resultate: Onder Kayamandi bevat die rivier gevaarlike vlakke van fekale besoedeling en dit hou gesondheidsgevare in vir alle persone war daarmee in aanraking kom. Op tot 13 miljoen Escherichia coli per 100 ml water is genoteer (boonste grens van veiligheid vir die mens is 1000 organismes per 100 ml water). Nie al die fekale kontaminasie is afkomstig van Kayamandi nie. Substansiele hoeveelhede kontaminasie dring die rivier binne op verskillende punte ver onder Kayamandi. Hierdie besoedelingslading is soms groter as wat van die hele Kayamandi afkomstig is. Watermonsters geneem onder Kayamandi is ondersoek om vas te stel watter ander siekteveroorsakende organismes ook teenwoordig was. Onder die organismes gevind was (3 hemolitiese Streptococcus Groep A en B, Mycobacterium intracellulare, Staphylococcus spp., Klebsiella spp., Pseudomonas spp. en baie ander. Die lys van patogene wat gevind is, het sulke emstige implikasies dat 'n vertroulike gesondheidswaarskuwing uitgestuur is na gesondheidsdienspunte en ander geaffekteerde organisasies in die gebied. (3 hemolitiese Streptococcus Groep B is nog nie vantevore aangemeld as lewensvatbaar geisoleer uit vryvloeiende natuurlike waters nie. Tekens is gevind dat daar organismes in die rivier voorkom wat weerstandig is teen chloorbehandeling en ook teen algemeen gebruikte antibiotika. Die E. coli organisme wat verskillende konsentrasies van chloorbehandeling oorleeef het, het ook verhoogde weerstand teen amoksisilien getoon wanneer hulle vergelyk was met onbehandelde E. coli organisme wat van die Plankenbrug Rivier gemonster was. Gedurende die gemeenskapsfase van die projek is daar 'n verlaging van besoedelingsvlakke in die rivier gevind gedurende die somers van 2000 en 2001 (let op dat "verbetering" hier nog glad nie "veilig" beteken nie). Dit kan toegeskryf word aan die veelvlakkige benadering wat die projek gevolg het. Aandag is geskenk aan diens en herstel van sanitasiegeriewe met 'n sterk klem op deur-tot-deur opvoedingsveldtogte met die oog op beter sanitasiegedrag, skepping van 'n sentrale aanmeldpunt vir blokkasies en brekasies, en opleiding van ambagslui (loodgieters, messelaars, ens) uit die gemeenskap om te help met onderhoud. Die gemeenskap het bemoedigende tekens getoon dat hulle beter sanitasie opvoeding verlang. Die verbetering in die besoedelingsvlakke in die rivier loop egter gevaar om terug te val na die vorige gevaarlike vlakke as daar nie beter ondersteuning en samewerking van die onderhawige owerhede verkry kan word nie. Daar was 16.9% van huishoudings wat een of meer gevalle van diarree aangemeld het gedurende die 5 weke van die opnameperiode - 'n baie hoe prevalensie siende dat die opname uitgevoer was gedurende 'n nat en koue winterperiode. Gevolgtrekkings: Aktiewe beplanning en ander stappe om die riool-indringing in die rivier die hoof te bied is gebiedend noodsaaklik en behoort sonder versuim ingestel te word. Die waterkwaliteit van die Plankenbrug Rivier stroomaf van Kayamandi is baie swak. Die water hou emstige gesondheidsgevare in en is ook 'n bedreiging vir die ekonomiese aktiwiteite stroomaf. Die nedersetting van Kayamandi demonstreer ook dat opvoeding, wanneer gekoppel aan onderhoud en herstel van bestaande toiletgeriewe in verlaging teweeg kan bring van besoedelingsvlakke, maar dat dit 'n voortgesette program moet wees en nie net sporadiese pogings nie.

Chemical pollution of freshwater is a worldwide environmental problem / eutrophication, heavy metals and salinity are amongst the most widely used indicators of pollution. The aim of this study was to assess the status of nutrients, heavy metals and salinity, and the seasonal variation int he Bottelary River.

Light Non-Aqueous Phase Liquids (LNAPLs) are used throughout the world for numerous applications, the most well-known being automotive fuels, such as petrol and diesel. The widespread production, distribution, storage and use of LNAPLs results in the ubiquitous occurrence of spillage to ground (Geller et al, 2000). Considering the hazardous nature of most LNAPLs due to their explosive and toxic characteristics, releases of LNAPLs to ground have well documented human health and ecological consequences. The occurrence of leaking underground and above-ground storage tanks at service stations and consumer installations is a common cause of contamination; and is described in literature for various countries of the world (Dietz et. al., 1986; Moschini et al, 2005; Mulroy and Ou, 1997; Harris, 1989; The Institute of Petroleum, 2002). Little failure data are however available for the South African context. In addition to this, data concerning the location and characteristics of sites storing LNAPLs in South Africa is similarly scarce. The study analysed data from three sources, namely the eThekwini Fire and Emergency Services data, GIS data and data from a local consultancy, in order to determine whether certain factors increased contamination risk posed by these facilities. The results indicated that contamination may be a result of numerous factors, but primarily line and tank failure. The type of installation was also found to have a significant influence on whether a site would be contaminated or not. In addition to the above, the results indicated that certain circumstances increase the severity of loss. The results indicated the need for more investigation to be performed into contamination as a result of LNAPL loss to ground, and the need for protective measures to be implemented for high risk sites where the likelihood and severity of a potential loss is high. Focus should then be centred on the probability of failure of non-ferrous pipework and GRP tanks to ensure adequate protective mechanisms are in place in the event of a failure of this newer infrastructure. In addition, a review of regulatory control of LNAPL storage in South Africa and the eThekwini Municipality, with reference to the international context, indicated the need for a specific department within the local government structure that manages LNAPLs with the objective of reducing contamination incidents. The continued use of underground storage of LNAPLs will always present a risk of failure/contamination due to the unseen nature of the installations and related infrastructure. It is this risk that requires regulatory management. Details of contaminated sites in South Africa should be within the public domain. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.

The aim of this study was to use plants to determine the degree of heavy metal contamination in water and sediments in order to effectively monitor and provide possible recommendation to improve the water quality in the aquatic ecosystem of the Bottelary River.

Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2019. / Background: A recent review on the effects of ambient air pollution on human health in sub-Saharan Africa, specifically calls for an urgent need for more epidemiological studies in developing countries due to a lack of data in these countries. Air pollution information on exposure is important for understanding and addressing its public health impact in developing countries. In many African countries, the spatial distribution of air pollutants has not been quantified even though air pollution is a global public health risk. The main goal of the study was to quantify and compare the seasonal spatial variation of household air pollution in the 4 Western Cape neighbourhoods. Methods: Weekly indoor and outdoor measurements of Particulate Matter (PM2.5), Sulphur dioxide (SO2), Ozone (O3), Carbon monoxide (CO) and Nitrogen dioxide (NO2) were conducted at 127 households in four informal settlement areas (Khayelitsha, Marconi-Beam, Masiphumulele and Oudtshoorn) during one month each in summer and winter. PM2.5 measurements were conducted using Mesa Labs GK2.05 (KTL) cyclone with the GilAir Plus Air Sampling Pump, Gases were measured using Passam passive samplers. Statistical analyses were performed using Stata V12. Simple linear regression was used to evaluate the relationship between continuous exposure levels and the respective predictor variables. These include distance to major roads, bus routes, open grills and waste burning sites. Results: The highest average weekly outdoor PM2.5 and NO2 concentrations for summer were recorded in Milnerton (8.76 µg/m3 and 16.32 µg/m3 respectively). However, the highest average concentrations during winter for PM2.5 were recorded in Oudtshoorn (PM2.5: 16.07 µg/m3), whilst the highest NO2, was recorded in Khayelitsha (NO2: 35.69 µg/m3). SO2 levels were consistently low during both seasons. Noordhoek generally recorded the lowest average levels for all pollutants. Winter average weekly concentrations were generally higher than the levels recorded in summer for all pollutants. In a sub-sample of indoor and outdoor measurements, the results were comparable for PM2.5, NO2 and CO. However, the results of Ozone (O3) showed relatively higher (~10 times) outdoor compared to indoor levels. Linear regression modelling results revealed that significant predictors of elevated exposure to PM2.5 were proximity to construction activities and open grills. Analysis demonstrated a clear dose-response relationship with distance, with open grills within 1000m associated with a 0.33 µg/m3 increase in PM2.5 to 6.77 µg/m3 at a distance of 25 meters. Results from the linear regression modelling revealed that significant predictors of exposure to NO2 were proximity to rapid transport bus stops, bus routes, taxi routes and major routes. Distance to rapid transport bus stops demonstrated an increase in NO2 between 0.09 µg/m3 (at 1km) to 2.16 µg/m3 (at 50m) during summer. A similar pattern was observed for taxi routes and bus routes displaying an increase of 6.26 μg/m3and 6.82 μg/m3 respectively within the proximity of 1000 meters. / MAUERBERGER Foundation Scholarship

The study focuses on the role of government in the provision of environmental programmes, events and campaigns. South Africa is a signatory to a number of environmental treaties and protocols hence it is expected to celebrate environmental days annually, such as World Wetland Day, National Water Week, World Environmental Week, Arbor Day and many more. The study considered the community of Masibekela, a remote rural village in Mpumalanga Province under the Nkomazi Local Municipality as its study area. Both qualitative and quantitative methods were applied to gather the necessary data from the four sets of respondents to a questionnaire survey, namely: the Sector Manager of Tonga Environmental Centre, traditional leadership and community members, learners and educators. The study discovered that the provision of environmental programmes, events and campaigns to the study area by the government leaves much to be desired. It lays bare that the community members of Masibekela are neglected environmentally by the government as compared to schools. The study also revealed contrasting features both in the knowledge and celebration of some of the environmental days by both the schools (learners and educators) and the general community members. A high percentage of learners and educators expressed their knowledge and celebration of environmental days since they are frequently visited by government officials to promote environmental programmes, events and campaigns geared towards environmental education and awareness but the same cannot be said about the traditional leaders and community members. It is recommended, among other things, that the Tonga Environmental Centre, as a custodian of provision of environmental programmes, events and campaigns, should be capacitated both in terms of human resources and strategic planning so as to meet its expectations. It is also recommended vi that more funding for bursaries for environmental studies for the youth should be made available and also more capital should be injected into the actual promotion of environmental programmes, events and campaigns. The National Department of Education in collaboration with the Department of Environmental Affairs should consider including Environmental Education in the school curriculum as a compulsory subject in all grades / Geography / M. A. (Geography)

In South Africa water is recognized as a crucial element in the battle against poverty, the cornerstone of prosperity, and a limiting factor to growth. The National Water Act 36 of 1998 recognizes that basic human and environmental needs should be met and that the use of water in all aspects must be sustainable. The Crocodile River (East) is situated in the north east of the Republic of South Africa and it is recognized as a stressed catchment in South Africa. The main impacts are domestic, industrial, agricultural, mining and afforestation activities. These activities pollute the river by discharging effluent as well as seepage from areas that support mining and intensive agriculture in to the river. The river catchment has been a center of research studies for many scientists either focusing on water quality or biological indicators separately. The aim of study was to determine the present ecological condition and the health of the Crocodile River. The objectives were to determine water quality status, identify possible sources of pollution and assess the spatial and temporal trends in ecological state. Fourteen monitoring sites were selected from the Crocodile River and its tributaries. The macro-invertebrates data were collected using the SASS 5 protocol and fish were collected using an electroshocker- catch and release method during high and low flow conditions of the year 2013. Water quality data was obtained by sampling using a polyethylene bottle from different sites within the Crocodile River and its tributaries from September 2012 until August 2013. The samples were analyzed by Mpumamanzi laboratory in Nelspruit and Waterlab in Pretoria. Additional water quality data was obtained from the Department of Water Affairs. Multivariate statistical methods were used to analyze all the data obtained. The multivariate statistical methods indicated that fish and macro-invertebrates species abundance, richness and evenness increase with the river flow distance downstream. Water temperature was one of the leading environmental variables for the structuring of fish and macro-invertebrates assemblage in the Crocodile River and its tributaries. A group formation of site during high and low flow condition by the Bray Curtis similarity and NMDS ordination indicated that many sites share similar macro-invertebrates or fish species. The one way ANOVA analysis indicated that there was no significance difference between macro-invertebrates richness and abundance during both flow conditions but there was a significance difference in fish richness and abundance between the two flow conditions. The PCA indicated that sodium has the highest physico-chemical impact amongst the physico-chemical parameters in the bi-plot followed by ammonium and nitrate. A correlation of physico-chemical parameters such as chlorine, total dissolved solid, electrical conductivity, sulphate and pH was observed. The levels of total dissolved solids and electrical conductivity were found to increase longitudinally as the river flows downstream. The dominance of single species within the macro-invertebrates and fish communities was an indication of imbalance of the communities within the sites. The presence of the macro-invertebrate family Beatidae and the fish species Chiloglanis pretoriae at sites CR3 and CR4 indicates a good water quality in the upper reaches during low flow condition as these species are sensitive to changes in water quality, while the presence of the macro-invertebrate family Pleidea and fish species Barbus viviparus at sites CR10 and KR1 during low flow condition indicated possible water pollution as these species tolerate changes in water quality and this was linked to the discharge of effluent from industrial, abandoned mines and run-offs from agricultural activities in the downstream reaches of the river. The low flow condition was dominated by sensitive species especially in the upper reaches than during high flow condition. The macro-invertebrates assessment index indicated that during low flow condition the Crocodile River was mostly at ecological class B (largely natural with few modification) above the Kwena dam, but from downstream of the dam the ecological category was in C class (moderately modified), while its tributaries are in ecological category B (largely natural with few modification). The fish response assessment index indicated that the ecological category for fish was mostly at C class (moderately modified) in the Crocodile River. The changes in macro-invertebrates communities and fish in the Crocodile River were believed to be associated with change of water quality and habitat modification due to flow modification. Agricultural activities in the upper reaches and a combination of industrial and mining activities in the middle and lower reaches of the Crocodile River were believed to be the sources of pollution that results in the change of water quality, fish and macro-invertebrates assemblage in the Crocodile River. Investing in the health of the Crocodile River is important for many Mbombela citizens and river dwellers as they rely on the functioning of the river for survival. / Environmental Sciences / M. Sc. (Environmental Science)

Steroid hormones belong to a group of compounds known as endocrine disruptors. They are hydrophobic compounds and are categorized as natural and synthetic estrogens. Some common household products have been implicated as estrogen mimics. Exposure effects of these compounds are felt by human and wildlife, such reproductive alterations in fish and frogs. They mainly introduced into the environment through veterinary medicines administration to animals and the discharges from wastewater treatment plants (WWTPs). In this study, a new alternative analytical procedure that is simple, rapid and fast for the determination and quantification of five steroidal hormones: estriol (E3), beta estradiol (β-E2), alpha estradiol (α-E2), testosterone (T), progesterone (P) and bisphenol A (BPA) using the High pressure liquid chromatography coupled to a charged aerosol detector (HPLC-CAD). These compounds were studied because of their strong endocrine-disrupting effects in the environment. Under optimum conditions, a linear graph was obtained with correlation coefficient (R2) ranging from 0.9952 - 0.9996. The proposed method was applied to the analysis of water samples from a wastewater plant and the results obtained were satisfactory. The limits of detection (LOD) for the target analytes in wastewater influent was between 0.0002 – 0.0004 μg/L and the limit of quantification (LOQ) was 0.001 μg/L respectively for each of the analytes. Enrichment factors of 148- 258, and extraction efficiency 84- 102% were obtained for the target analytes; relative standard deviations (% RSD) for m = 6 were between 2.8 and 7.6%. The concentration of the EDCs in environment sample was between 0.2 - 2.3 μg/L. / Chemistry / M. Sc. (Chemistry)

The original aims of this project were to investigate the potential for phytoremediation, with emphasis on metal accumulation, of three contrasting industrial processing wastes. These were tailings material (PT) from the decommissioned Pering Pb/Zn Mine (Reivilo, North West Province, South Africa (SA)), smelter slag (SS) from the Samancor Mnsmelter (Meyerton, Gauteng, SA) and electro-winning waste (EW) from MMC (Nelspruit, Mpumalanga, SA). It became evident, however, early in the project, that the use of metal hyperaccumulating plants was not a viable technology for these wastes. The project objectives were thus adapted to investigate alternative remedial technologies. The use of endemic and adapted grass species was investigated to revegetate the PT. In addition, chemically-enhanced phytoremediation was investigated to induce metal hyperaccumulation by grasses grown in the PT (Part 1). Revegetation of the SS and EW were not considered feasible, thus land disposal of these two Mn-rich processing wastes was investigated (Part 2). Part 1 - Revegetation of tailings from Pering Mine The PT was found to be alkaline (pH > 8.0), and consisted mainly of finely crushed dolomite. It was generally nutrient poor with high amounts of readily extractable Zn. It also had a very high P-sorption capacity. Seven grass species (Andropogon eucomus Nees; Cenchrus ciliaris L.; Cymbopogon plurinodis Stapf ex Burtt Davy; Digitaria eriantha Steud; Eragrostis superba Peyr; Eragrostis tef (Zucc.) Trotter and Fingeruthia africana Lehm) were grown in PT treated with different rates of inorganic fertiliser under glasshouse conditions. The fertiliser was applied at rates equivalent to 100 kg N, 150 kg P and 100 kg K ha-1 (full), half the full rate (half) and no fertiliser (0). Seed of C. ciliaris, C. plurinodis, D. eriantha, E. superba and F. africana were collected from Pering Mine. Seed of A. eucomus was collected from the tailings dam of an abandoned chrysotile asbestos mine. These were germinated in seedling trays and replanted into the pots. A commercial variety of E. tef was tested, but due to poor survival this species was subsequently excluded. The foliage and root biomass of the grasses and concentrations of Ca, Cu, Fe, K, Mg, Mn, Pb and Zn in the foliage were determined. The yield of all the grasses increased with an increase in fertiliser rate, with a significant species by fertiliser interaction (p = 0.002). The highest yield was measured for C ciliaris, followed by D. eriantha (4.02 and 3.43 g porI, respectively), at the full fertiliser application rate. Cymbopogon plurinodis was the third highest yielding species, while the yields of E. superba and F. africana were similar. There were positive linear correlations between foliage yield and fertiliser application rate for all grasses. The root biomass of the grasses also increased with an increase in fertiliser application rate. The interaction between grass species and fertiliser level had a non-significant (p = 0.085) effect on the yield of grasses, though there were significant individual effects of species (p < 0.001) and fertiliser (p < 0.001). Digitaria eriantha had the highest root biomass at each fertiliser application rate, followed by C plurinodis and C ciliaris. Similarly to foliage yield, there were positive linear correlations between root biomass and fertiliser application level. Positive, linear correlations were found between foliage yield and root biomass, though the strength of these varied. The weakest correlation was found for D. eriantha (R2 = 0.42) but this was attributed to a moderately high variance in foliage yield and roots becoming potbound. Generally, nutrient concentrations were within adequacy ranges reported in the literature, except for P concentrations. This was attributed to the high P-sorption capacity of the PT. Zinc concentrations were higher than the recommended range for grasses, and also increased with an increase in fertiliser application rate. This was attributed to the high available Zn concentrations in the PT and improved growth of the grasses at higher fertiliser application rates. It was recommended that C ciliaris and D. eriantha be used for revegetation due to high biomass production and that E. superba be used because of rapid growth rate and high self-propagation potential. Both C plurinodis and F. africana can also be used but are slower to establish, while A. eucomus was not a suitable species for revegetation of the PT. Inorganic fertiliser improved the growth of all these species and is recommended for the initial establishment of the grasses. An experiment was conducted to investigate the potential of inducing metal hyperaccumulation in three grass species (C ciliaris, D. eriantha and E. superba) grown in the PT. Grasses were grown in fertilised tailings for six weeks, then either ethylenediaminetetraacetic acid (EDTA) or diethylentriaminepentaacetic acid (DTPA) was added to the pots at rates of 0, 0.25, 0.5, 1 and 2 g kg-I. Grasses were allowed to grow for an additional week before harvesting. The concentrations of Cu, Pb and Zn were determined in the foliage. The interactive effect of species and chelating agent on the uptake of Cu was marginally significant (p = 0.042) and non-significant for Pb and Zn (p = 0.14 and 0.73, respectively). While the addition of the chelating agents resulted in an increase in Pb uptake by the grasses, it did not induce metal hyperaccumulation in the grasses. This was attributed to the ineffectiveness of the chelating agents in the PT in the presence of competing base cations (mainly Ca). The use of this technology was not recommended. Part 2 - Land disposal of Mn-rich processing wastes Chemical characterisation of the SS showed that it was an alkaline (pH > 9.5), Mn-rich silicate (glaucochroite), that generally·had low amounts of soluble and readily extractable metals. Acidic extractants removed high amounts of Mn, Ca and Mg, attributed to the dissolution of the silicate mineral. The EW was highly saline (saturated paste EC = 6 780 mS m,l) with a near-neutral pH. It had high amounts of soluble Mu, NHt+, S, Mg, Ca and Co. The primary minerals were magnetite, jacobsite (MnFe204) and gypsum. The effect of SS and EW on selected chemical properties of six soils was investigated by means of an incubation experiment, and their effect on the yield and element uptake by ryegrass was investigated in selected soils under glasshouse conditions. Five A-horizons (Bonheim (Ba), Hutton (Hu), lnanda (la), Shortlands (Sd) and Valsrivier (Va» and an Ehorizon (Longlands (Lo» were treated with SS at rates of 30, 60, 120,240 and 480 g kg'l and EW at rates of20, 40,80,160 and 320 g kg'l. Soils were incubated at field capacity at 24 QC and sampled periodically over 252 days. The soil pH, both immediately and over time, increased, while exchangeable acidity decreased after the addition of SS to the soils. The pH at the high rates of SS tended to be very high (about 8). The electrical conductivity (EC) of the soils also increased with an increase in SS application rates and over time. The most marked changes tended to occur in the more acidic soils (e.g. la). In the soils treated with EW, there was generally an increase in the pH of the acid soils (e.g. la) while in the more alkaline soils the pH tended to decrease (e.g. Va), immediately after waste application. There was a general decrease in pH over time, with a concurrent increase in exchangeable acidity, due to nitrification processes. The EC of all the soils increased sharply with an increase in EW application rate, attributed to the very saline nature of the EW. Water-soluble Mn concentrations in the soils treated with SS tended to be below measurable limits, except in the acid la. Iron concentrations decreased with an increase in SS application rate and over time for all soils. The water-soluble concentrations of Mn, Ca, Mg and S increased sharply with an increase in EW application rate in all soils. There was also a general increase in Mn concentrations over time. Iron concentrations tended to be low in the EW-treated soils, while Co concentrations increased as EW application rate increased. Exchangeable (EX, 0.05 M CaCh-extractable) concentrations of Fe, Co, Cu, Zn and Ni were low in the SS-treated soils. The concentrations of EX-Mn tended to increase with an increase in SS application rate in the la soil, but generally decreased in the other soils. There was also a decrease over time, attributed to the high pH leading to immobilisation of Mn. The EX-metal concentrations of the EW-treated soils were generally low, except for Mn. The concentrations of EX-Mn increased sharply as EW application rate increased. The contribution of EX-Mn was calculated to range from 209 to 3 340 mg Mn for EW rates of 20 to 320 g kg-I, respectively. In the Lo soil the expected amount of Mn was extracted at the different EW application rates. In the other soils the EX-Mn concentrations were typically higher than expected. This was attributed primarily to the dissolution ofMn from the EW due to the interaction between soil organic matter and the EW. There was generally an increase in EX-Mn concentrations over time, attributed to the decrease in pH of the soils treated with EW. The above-ground biomass production of ryegrass grown in Lo and Hu soils treated with SS increased at low application rates, but decreased again at the highest rates. The reduction in yield was attributed to an increase in soil pH leading to trace nutrient deficiencies. At the lower SS application rates, nutrient concentrations of the ryegrass tended to be within typical adequate ranges reported in the literature. Of concern was the elevated Mn concentration in the ryegrass foliage, though no toxicity symptoms were seen. This was attributed to the dissolution of the silicate mineral due to soil acidification processes and the possible ameliorating effect of high Ca and Si concentrations on Mn toxicity. The growth of ryegrass was generally poor in the Hu soil treated with EW and it did not survive beyond germination in the Lo soil treated with EW. In the Hu soil plants grew well in the 20 and 40 g kg-I EW treatments, but died at the higher rates. In both cases mortality was thought to be due to the high salinity that resulted in toxicity and osmotic stress in the newly germinated seedlings. The improved growth at the lower rates ofEW, in the Hu soil, was attributed mainly to increased N availability. The concentrations of Mn in the foliage were elevated in the soils treated with EW. A pot experiment was conducted to test the effect of applying either humic acid (HA) or compost (at a rate of 20 g kg-I) with lime (at rates of 0, 5 and 10 Mg ha-I) on the growth and nutrient uptake of ryegrass grown in the Hu soil treated with EW at rates of 0, 10, 20 and 40 g kg-I. A basal P-fertiliser was also applied in this experiment. The highest yields were measured in the treatments receiving either HA or compost at the highest application rate ofEW. The addition oflime did not improve the yield of the HA treatments, but did in the compost treatments. Generally, nutrient concentrations were adequate. The Mn concentrations were markedly lower than expected, and this was attributed to the formation of insoluble Mn-P compounds due to the addition of fertiliser. The effect of either HA or compost on Mn concentrations was not marked, but lime reduced Mn uptake. A leaching column experiment showed that, generally, the Mn was not readily leached through a simulated soil profile, though the addition of compost may enhance mobility. There was also evidence to indicate an increase in salinity and that Co concentrations of the leachate may be a problem. These data suggest that soil organic matter may be a very important factor in determining the release of Mn from the wastes, notably the EW. The land disposal of the SS and EW was not recommended at the rates investigated here, as both showed the potential for Mn accumulation in above-ground foliage, even at low application rates, while high application rates negatively impacted on plant growth. It appears that P-compounds may be beneficial in reducing Mn availability in the EW, but further testing is required. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

Chemical pollution of freshwater is a worldwide environmental problem / eutrophication, heavy metals and salinity are amongst the most widely used indicators of pollution. The aim of this study was to assess the status of nutrients, heavy metals and salinity, and the seasonal variation int he Bottelary River.