The Cu(In,Ga)Se2 (CIGS) thin-film solar panels (TFSPs) are widely used in integrated photovoltaic (PV) and solar power systems because of their perfect PV characteristics and ductility. However, the semiconductor layers of these panels contain potentially toxic metals. In this study, the potential environmental pollution arisen by CIGS TFSP treated as construction trash at the end of their useful life was examined. Acid extraction was used to simulate leaching toxicity followed by burying CIGS TFSP material in different soils, namely a synthetic soil, a Mollisol, and an Oxisol, to determine whether metal pollutants might be released into the soil. A vegetable, Brassica parachinensis L. H. Bariley (VegBrassica), was selected to grow in these polluted soils to investigate the uptake of metals and their bioaccumulation. The simulative remediation of contaminated soils was carried out using a remediation module created by the combination of activated carbon and modified mineral waste material (MMWM) in this research. The activated carbon derived from the waste biomass material was produced by an environmental friendly method, and the MMWM was obtained through a thermal dehydroxylation treatment. The physiochemical properties of MMWM, with focusing on mineral phase transformation, were related to the changes in surface morphology due to dehydroxylation occurred during the process of thermal treatment of MMWM samples, and the adsorption performances of metal (lead, Pb) and organic compound (methyl orange, MO) onto this newly modified MMWM were studied. Furthermore, an end-of-life treatment method was designed and proposed for harmless disposal of CIGS TFSP. Various metals, including Pb, zinc (Zn), nickel (Ni), chromium (Cr), gallium (Ga), copper (Cu), indium (In) and aluminum (Al) were found to be released into the soil and caused contamination when scrapped end-of-life CIGS TFSP were buried, and the rates of metal release changed with the variations of both the amounts of CIGS TFSP material in the soil and the soil properties. The increases in concentrations of heavy metals such as Zn, Cu, Ni, Ga, Pb, In, and Cr were correlated with the amounts of CIGS TFSP material added in soils. The Pollution Index and the Nemerow Contamination Index calculated from our results confirmed that, when buried, the CIGS TFSP material polluted the soil. Plants grew well in the synthetic soil and the Mollisol, but those in the Oxisol showed prominent signs of chlorosis and died after 30 days. The bioaccumulation factor (BF) and concentration of Zn were 3.61 and 296 mg/kg, respectively in VegBrassica grown in the synthetic soil with 10% (200 g to 2 kg of soil) of added CIGS TFSP, while the BF and concentration of In were 3.80 and 13.72 mg/kg, respectively in VegBrassica grown in the Mollisol, indicating that bioaccumulation occurred. The thermally treated MMWM samples showed morphological transformation mainly on surface based on the scanning electron microscopy (SEM) observations, and an increasing trend in BET specific surface area (SSA) from 120 to 500 ℃ followed by a decreasing trend up to 1000 ℃. Thermal modification had successfully improved Pb adsorption capacity up to 515 mg/g, corresponding to MMWM modified at 600 ℃ with an SSA of 6.5 m2/g. The MO adsorption capacity was also improved after thermal treatment of MMWM, which performed the best adsorption of 87.6 mg/g at 400 ℃. The adsorption of Pb and MO were mainly chemisorption and monolayer coverage, as pseudo-second-order model and Langmuir equation displayed good relationships of correlation for Pb and MO adsorption data. It is therefore indicated that the newly designed soil remediation modules could significantly remove metals from the contaminated soils. In summary, c

This study investigates the incorporation of Environmental Education as a phase organiser in learning programmes in the Foundation Phase by educators as recommended by Curriculum 2005. A literature review indicates the role which Environmental Education plays in society. It presents a feasible strategy for changing attitudes to the environment. It is interdisciplinary and holistic, relevant, practical and focuses on learners and learning. It can improve the quality of life of all by enabling people to utilise resources, make informed decisions, apply and transfer knowledge, thereby empowering others. An empirical investigation adopted a qualitative research approach. Participants in a case study from primary schools in the Malamulele area, Northern Province, as well as two specialists were purposefully selected. Multiple methods of data collection, such as observation. and in-depth Interviews based on questionnaires, were used. Photographs and relevant documents complemented the data gathering. Finally, recommendations based on the findings were made. / Educational Studies / M.Ed. (Environmental Education)

M.Sc. / A comparative study was undertaken in the Olifants River catchment, to determine the water quality at two dam sites, namely, Bronkhorstspruit Dam (control) and Loskop Dam (polluted) in the upper Olifants River system and two river point, namely, at Mamba and Balule in the Kruger National Park, in the lower Olifants River system. Data was obtained during the physical and chemical analysis of water and sediment samples, and during bioaccumulation studies using Atomic Absorption spectrometry, testing for aluminium, chromium, copper, iron, lead, manganese, nickel, strontium and zinc. These tests were conducted on the liver, skin, muscle and gills of Clarias gariepinus. The information collected from Mamba and Balule, was compared with a previous study carried out primarily in the Kruger National Park by Marx, (1996). The study undertaken by Marx (1996) was carried out during a drought period, which allowed for the comparison with results recorded after flooding during the present study. This current research project therefore allowed for the comparison between two different water sources, namely, that of dams and rivers, and under varying environmental conditions. The Aquatic Toxicity index (ATI) developed by Wepener et al. (1992) was employed to facilitate the comparison between the water physical and chemical parameters that were measured, at each sample site, with a single variable being calculated for each sample site per survey. The water quality (ATI values) at the two control sites namely, Bronkhorstspruit Dam and Balule deteriorated substantially after the floods. High water levels due to the floods had a dilution effect on the concentration of pollutants however, toxicants were washed in from upstream and due to surface runoff. The removal of the purifying reed beds upstream of Balule and at the inflow to Bronkhorstspruit Dam, resulted in the release of latent sludge containing metals and organic pollutants into the water column. The ATI value's obtained for the two control points were similar or even higher than those obtained for the two polluted sites namely at, Loskop Dam and Mamba for the autumn and winter sampling periods. During following surveys the water quality at all four sample sites improved, returning to pre flood values by the last survey in summer, namely reflecting similar values as those recorded by Marx (1996) at Balule, Mamba and Loskop Dam for the same period. Sediment concentrations recorded a similar trend to that for water at all four sample sites throughout the study. The bioaccumulation study indicated that the gill concentrations recorded were generally the highest, followed by the liver concentrations. From this one may deduce that gills were the dominant site for metal absorption by the fish, with the excretion of metals also taking place via this route. Liver concentrations are an indication of the activation of protective _mechanisms in the fish sampled, the high concentrations recorded indicate the high physiological response the fish have had to the various levels of exposure. The low concentrations recorded in the muscle indicates the effectiveness of the liver in the detoxification of the fish, indicating that only limited storage of the various metals tested for took place at this site. Skin concentrations were quite high, these concentrations represent the products of an excretory process, which takes place via the skin. The order of concentrations recorded during the present study, were similar to the orders recorded by Marx, (1996) and other authors, however, the order of the skin and muscle concentrations were often reversed. This may be due to the increased excretion of these metals via the skin, resulting from increased exposure to these metals after the floods. Thus the increased exposure

D.Phil. / South African water resource management policies as well as the country's water law have been under review over the past three to four years. The Water Law Principles, which were established as part of this review process, indicate a commitment to sustainable development of water resources and the protection of an ecological "Reserve". Such policy goals highlight the limitations of conventional water quality management strategies which rely on stressor monitoring and associated regulation of pollution. The concept of an assimilative capacity is central to the conventional water quality management approach. Weaknesses inherent in basing water management on the concept of assimilative capacity are discussed. Response monitoring is proposed as a way of addressing some of the weaknesses. In fact, the inadequate use of biological indicators and techniques in monitoring and evaluating the quality of resources has been identified as a major factor responsible for the continuing decline in the health of natural resource systems. With advances in environmental monitoring over the last decade, it has become clear that biological techniques and protocols need to become part of monitoring in order to allow effective assessment and protection of aquatic resources. One way of incorporating response measures into resource assessment is through the use of toxicological assays. As an example, a toxicological assessment of the environmental risk associated with an organic pesticide (fenthion) is presented. Acute and chronic assays were conducted with a spectrum of test organisms. These toxicological response results provided an ability to predict the ecosystem response that can be expected from certain concentrations of fenthion in the environment. Theoretically, it would be possible to design a risk assessment experiment for every new anthropogenic substance. However, in terms of cost and time, it would not be practically feasible to execute such experiments. To overcome this problem, a method has been developed to derive water quality criteria for toxic substances using existing toxicological data. This provides water resource managers with a readily available set of values to guide them in decision-making. It is demonstrated how available acute and chronic toxicity data can be synthesised into acute and chronic water quality criteria for the protection of aquatic life. As these criteria are intended to extend protection to ecosystems country-wide, they are very conservative by design. Although a set of numeric water quality criteria provides an important tool to water quality managers, the limitations associated with the use of these criteria must be recognised. x Limitations relate either to the design of toxicity experiments or to the use of a chemical-specific approach alone in water resource management. In order to overcome these limitations, three broad supporting technologies are proposed, namely whole effluent toxicity (WET) testing, sitespecific adjustment of water quality criteria, and in-stream biological assessments. Whole effluent testing aims at evaluating the toxic effects of an effluent on organisms. In doing so, acute and chronic toxicity testing (and thus biological responses) becomes part of effluent regulation. An effluent control programme that incorporates toxicity-based standards and compliance criteria is proposed. One of several approaches that can be used for deriving site-specific water quality criteria is the calculation of a water-effect ratio. It is demonstrated that the water-effect ratio method could result in significant adjustments to the national water quality criteria. Although more development and local testing would be required, such site-specific criteria could be in the interest of both ecosystem protection and economic development. In-stream biological assessments introduces a type of response monitoring which provides insight into the overall integrity of aquatic ecosystems. A comprehensive biomonitoring programme is designed. To adhere to the objectives of this programme, specifications have been developed for the selection of sampling sites, the selection of biological and habitat indicators, and the management of the resulting data. This programme is referred to as the River Health Programme (RHP). The ultimate aim of any monitoring programme is to provide useful data. Such data must contribute to effective decision-making. To ensure that the RHP becomes truly operational as a management information system, a step-wise procedure is proposed for linking the collected data with management actions. It is demonstrated how following of this systematic and iterative procedure would facilitate ongoing learning and improvement of the individual steps (e.g. data collection and assessment, goal setting, selection and implementation of management actions) as well as the overall procedure. As a final step, the dynamics that influence the transition of any new technology from scientific development to operational application are explored. The RHP is used as a case study and theoretical models from the field of the management of technology are used to provide valuable insights. Four key components of the RHP design are analysed, namely the (a) guiding team, (b) concepts, tools and methods, (c) infra-structural innovations and (d) communication. These key components evolved over three broad life stages of the programme, which are called the design, growth and anchoring stages.

D.Phil. / By virtue of its position on the eastern border of South Africa, the Kruger National Park (KNP) receives the flow of six main riven, of which the greater part of the specific catchment areas are situated upstream from the park itself. The Olifants River has the largest catchment area both in size and in proportion of catchment area beyond the park boundary. Increased competing demand for water by the urban, industrial, mining and agricultural sectors within the catchment boundaries of the Olifants River has focused attention on the ecological water requirements of the river. Of particular concern was the high degree of mineralisation of the Olifants River due to mining activities on the western boundary of the KNP. When one considers the demand for water by the Kruger National Park it is evident that water is required for more than one use, i.e. for potable use, game watering and ecosystem (aquatic and riparian) maintenance. In order to facilitate proper water quality management it is necessary to develop a comprehensive water quality management plan for the river. The development of such a plan requires a thorough understanding of the fate and effects of pollutants in the environment. It is furthermore important to have reliable information on the trends and status of important water quality determinants in these systems. This study was therefore aimed at investigating the metal ecotoxicology of the lower Olifants River and the Selati River, a tributary of the Olifants River which flows through the Phalaborwa area. Water quality is a driving variable in aquatic ecosystems. Full assessment of water quality of the Olifants River included evaluation of the physical, chemical and biological attributes of the system. The difference between the physical/chemical and biological attributes is that the former provide an instantaneous and often specific assessment of the water quality, whereas the latter integrate changes in the system over time. Water and sediment samples were collected bi-monthly from February 1990 to February 1992 at six stations along the lower Olifants River, one in the Selati River and one in the Letaba River. At each of these sites physical and chemical water quality characteristics were measured. Two metal bioaccumulation indicator species, Labeo rosae and Oreochromis mossambicus, were also sampled during the same period at three stations in the Olifants River and at the Selati River sampling station. Two additional surveys were undertaken to reference sites in the KNP (i.e. Pioneer Dam, and Nhlanganini Dam) during February 1992 and April 1992 respectively. Tissue samples (muscle, gill, liver, gonads, fat and blood) were collected and analysed for Cr, Cu, Fe, Mn, Ni, Pb and Zn using atomic absorption spectrophotometry. The routine monitoring of chemical and physical water quality attributes produces large quantities of complex data which are often difficult to interpret. To reduce the complexity, data may be standardised and summarised into an index. The Aquatic Toxicity Index (ATI) that was developed Metal Ecotoxicology in the Olifants River it Summary during this study presented the water quality of all the sampling stations, during each survey as a single value. This value reflected the water quality's suitability-for-use by fish at the different sampling stations. The ATI showed definite temporal and spatial trends in water quality in the Olifants River. The Selati River was the main contributing factor to the poor water quality measured in the Olifants River within the KNP. This was due to high TDS, metal and fluoride concentrations. Deterioration of the water quality was experienced during flood conditions when the turbidities and total metal concentrations increased. The water quality generally increased between summer and winter surveys (February to June). Bioindicators are species used to quantify biologically available level of metals in the aquatic ecosystem. These organisms take up metals from the ambient water and from food, and the concentrations in their tissues (or changes in concentrations) provide a time integrated measure of metal bioavailability. Temporal bioavailability of metals in the tissues of the bioindicators showed similar trends to the water quality. Highest metal concentrations were measured in fish tissue samples collected during flood conditions (December 1990) and during low-flow conditions (June to October). This was attributed to increased exposure due to metal adsorption to suspended sediments during the flood conditions and to increased ambient metal concentrations during lowflow conditions. The distribution of metals in tissues varied based on the uptake, depuration and metabolism strategies for each metal. In general the gill tissue bioaccumulated the highest metal concentrations, with only Cu and Fe occurring in higher concentrations in liver tissue. Significant positive correlation's were found between bioaccumulation in muscle tissue and the other tissues: Space-bulking and time-bulking of results were carried out to elucidate spatial bioaccumulation patterns. The highest bioaccumulation of Cu, Pb and Ni were recorded in samples from the Selati River, whereas Zn and Cr concentrations were the highest in the Olifants River. An equilibrium partitioning (EP) technique was used to integrate bioaccumulation data and metal concentrations in different phases of the water and sediment and produce specific Cu and Zn criteria for the Olifants and Selati rivers. Although there is a multitude of data available for Cu and Zn toxicity and BCF's, the quality criteria produced during this study, for the first time, made use of results obtained under local conditions. The results from bioaccumulation studies carried out in the field can not provide information regarding the potential effects or the risks the metals may pose to the exposed organisms. Therefore the susceptibility of the organisms to metal contamination can be determined using laboratory studies. Physiology is toxicology's closest relative and contributes markedly in assessing the toxicological risk of metals. Bioassays were conducted to determine the uptake kinetics, acid-base disturbances and haematological effects of a metal mixture containing Cu, Fe and Zn on Tilapia sparrmanii. The effects of the individual metals (Cu, Fe and Zn) and different Metal Ecotoxicology

M.Ed. (Environmental Education) / Please refer to full text to view abstract

Heavy metal bioaccumulation in aquatic organisms may occur through direct or indirect uptake routes. Research indicates that the significance of uptake route varies with contaminant and organism exposed. The relative importance of different metal sources in aquatic systems was investigated by exposing freshwater snails to dietary or dissolved sources of cadmium. Snails were exposed to control, contaminated food only, contaminated water only, and contaminated food and water treatments. During the 15-day exposure, samples were taken to determine Cd concentration in snail soft tissue, snail shell, algal food, and overlying water. Analyses of snail soft tissue and shells indicate that exposure route significantly affects Cd concentrations in the tissues. In both cases, dissolved Cd is the primary contributor to metal body burden.

Effects of episodic exposures have gained attention as the regulatory focus of the Clean Water Act has shifted away from continuous-flow effluents. Standardized laboratory toxicity tests require that exposure be held constant. However, this approach may not accurately predict organism responses in the field following episodic exposures such as those associated with rain-driven runoff events or accidental pollutant discharge. Using a modified version of the 7-day short-term chronic test recommended by the US Environmental Protection Agency, Ceriodaphnia dubia were exposed to copper or cadmium for durations ranging from 1 minute to 24 hours. In addition, adult reproductive recovery and effects on second generation individuals was assessed following select copper exposures. Finally, cadmium exposures were compared in reconstituted hard water (RHW) and municipal treated wastewater effluent (TWE). Following exposure, organisms were transferred to clean RHW or TWE and maintained for the remainder of the test. No- and lowest observed effect concentrations (NO- and LOECs) increased logarithmically with respect to logarithmic decreases in duration regardless of metal, endpoint or water type. Effective concentrations of cadmium however, were usually higher than those of copper, especially in TWE. LOECs for C. dubia survival following 24-hour and 5-minute exposures to copper were 116 and 417 µg/L, respectively. LOECs for fecundity were 58 and 374 µg/L, respectively. Neonate production of first generation adult C. dubia appeared to recover from pulsed copper exposure upon examination of individual broods. Cumulative mean neonate production however, showed almost no signs of recovery at exposure durations ≥3 hours. Pulse exposure to copper also resulted in diminished fecundity of unexposed second generation individuals. Such effects were pronounced following parental exposure for 24 hours but lacking after parental exposures ≤3 hours. LOECs for C. dubia survival following 24-hour and 5-minute exposures to cadmium in RHW were 44 and 9000 µg/L, respectively. LOECs for fecundity were 16 and 5000 µg/L, respectively. In TWE, LOECs for C. dubia survival were 83 and >10,000 µg/L, respectively. LOECs for fecundity in TWE were 48 and 7000 µg/L, respectively. Runoff pollution is site and event specific, however, data presented herein may be useful as a predictive tool under various conditions.

No description available.

No description available.