Thesis (PHD)--University of Montana, 2009. / Contents viewed on December 19, 2009. Title from author supplied metadata. Includes bibliographical references.

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: Chip breaking; prediction; turning; grooved inserts. Includes bibliographical references (p. 113-121).

M.Sc. (Zoology) / Please refer to full text to view abstract

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

This study proposed and evaluated a waste-to-resource strategy for beneficially using solid waste as ceramic raw materials. The sludge generated from waterworks and sewage treatment processes contains significant amounts of aluminum and iron, and the industrial sludge is enriched with high metal content. The hazardous metals in waste sludge may lead to metal bioaccumulation and cause adverse effects for ecosystem. This study aims to stabilize copper- and zinc-laden sludge in commonly available ceramic products, and to beneficially use waterworks and sewage sludge to incorporate waste metals. The study was first investigated by sintering simulated metal-laden sludge with Al-rich (γ-Al2O3, -Al2O3, kaolinite, mullite) and Fe-rich (Fe2O3) precursors. Secondly, the practicability of recycling Cu-bearing electroplating sludge as a part of ceramic raw materials was evaluated through thermal interaction with Al-rich precursors. Furthermore, the potential of using water and sewage treatment works sludge to stabilize metals were also examined. Sintering procedures were carried out within 650-1450 oC for 3 h, and phase transformations were studied using X-ray diffraction (XRD) with the quantification technique of Rietveld refinement analysis. The formation of CuAl2O4 spinel was initiated at 650 oC using γ-Al2O3, and the maximum copper transformation reached 80%. The copper incorporation into CuAl2O4 started at 850 oC and reached 95% in -Al2O3 system. The growth of CuAl2O4 was found at 750 oC using kaolinite, but at 900 oC in mullite system. The maximum copper transformation for both kaolinite and mullite reached ~80%. With CuAl2O4, decomposing, the formation of CuAlO2 predominated in alumina systems, but CuO and Cu2O were found in kaolinite and mullite systems. When using Fe2O3, the CuFe2O4 with tetragonal structure was observed at lower temperatures, and the cubic CuFe2O4 became predominant at 1000 oC. The formation of ZnAl2O4 spinel started at 750 oC in γ-Al2O3 system and at 950 oC in -Al2O3 system, respectively. The zinc transformation completed in both γ-Al2O3 and -Al2O3 systems at higher temperatures. The coexistence and competition between ZnAl2O4 and Zn2SiO4 were found using kaolinite and mullite. The increase of temperature to 1350 °C resulted in complete zinc transformation to ZnAl2O4 in mullite system. Through leaching tests, aluminates and ferrites were found to be superior to oxide and silicate phases in immobilizing hazardous metals. The leachates of aluminates and ferrites exhibited the behavior of incongruent dissolution, and the Zn2SiO4 leachate showed congruent dissolution. The CuAl2O4 spinel was observed when sintering Cu-laden electroplating sludge with aluminate precursors. The copper leachability decreased with CuAl2O4 developing and the lowest copper concentration in leachates was within the optimal temperature range for CuAl2O4 generation. Both copper and zinc were successfully incorporated into the spinel structure using waterworks sludge, and the cubic CuFe2O4 became the main component when using sewage sludge to stabilize copper. Overall, this study demonstrated a promising process to stabilize hazardous metals in waste materials, such as sludge, ash, and slag, through sintering with the inexpensive ceramic precursors. This may provide an avenue for economically reduce the environmental hazards of toxic metals by reliably blending them into the marketable ceramic products. / published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

Waste water from the mining industry is generally extremely complex and contains numerous species which influence the adsorption of the metals to any biomass. A variety of factors need to be addressed before treatment is considered viable. It is also beneficial to establish the binding characteristics of the metal of interest to maximise its interaction with the biomass to be utilised. Azalia filiculaides was investigated in the adsorption of gold(III), lead(II), iron(ID), copper(II) and platinum (IV). In batch studies, the optimum biomass and initial gold(III) concentrations were found to be 5 gIL and 8 mgIL respectively. The adsorption of gold(ID) is principally pH-dependent with optimal removal at pH 2. Lead(II), iron(III) and copper(II) did not compete with gold(III) adsorption under equimolar and simulated effluent conditions. Halides, with increasing affinity for gold (chloride < bromide < iodide), can affect gold uptake with the soft base, iodide, exhibiting the most inhibition (25%) and the hard base, chloride, O%. Mercaptoethanol (soft base) showed no interference in gold(III) adsorption while the presence of sulphate (hard base) and sulphite (borderline base) showed that concentrations in excess of 1 0 mM may adversely affect gold(ill) uptake, most likely due to competition for cationic sites on the biomass. Column studies, better suited to high volume treatment, indicated that a flow-rate of 5 mL/min and an initial gold(ill) concentration of 5 mgIL was optimal. Competitive effects between lead, iron, copper and gold again showed little or no interference. The halides, chloride, bromide and iodide, affect gold(ill) uptake similarly to the batch studies, while the bases mercaptoethanol and sulphate minimally affect gold(III) binding with sulphite severely hampering adsorption (70% inhibition). To optimise gold desorption, preliminary batch studies indicated that a ratio of 1:1 of adsorbentdesorbent was optimal, whilst gas purging of thiourea with oxygen, air and nitrogen decreased gold elution in proportion to decreased amounts of oxygen. A series of desorbents were utilised, in column studies, to optimise and determine the speciation of bound gold. The presence of an oxidant with thiourea enhanced desorption greater than 3 fold when compared with thiourea alone. Thiourea desorption studies, aided by the oxidant, suggest that gold is present in the + I and 0 oxidation states. Ultimately thiourea, perchloric acid and hydrochloric acid was found to be the most optimal elutant for gold (J 00% recovery). For selective metal recovery oflead and copper, pre-washing the plant material with water, utilising an acid (0.3 M nitric acid), pumping in an up-flow mode, and recycling the desorbent six times was found to be optimal elutant for gold (J 00% recovery). Cost analysis of utilising elutant versus incinerating the biomass for gold recovery indicated the latter as the most economical. Over a 5 cycle adsorption and desorption series, acid desorption before each adsorption cycle was found to result in greater than 92% desorption for lead and 96% for copper. Gold recovery was 97% with incineration. A preliminary study with gold effluent (Mine C) indicated that nickel and sulphate was removed in batch and column studies. Gold removal was found to be 100% and 4% in batch and column studies respectively. Adsorption of gold in the effluent study was accompanied by the release ofHt. Modifying the plant material with various reagents failed to identify the primary binding sites and the role of polysaccharides, proteins and lipids in gold(ill) uptake. The mode of gold binding is suggested as being initially ionic, this is very rapid, with the interaction of the anionic complex, [AuCI₄]". with the cationic biomass (PH 2). This eventually leads to the displacement of the chloride ligand(s) initiating covalent binding. Spectral studies of the chemical interaction between gold and the representative tannins indicated the protonated hydroxy groups to be responsible. All evidence suggests that the binding mechanisms of gold are not simple. Preliminary adsorption studies of platinum by Azalia filiculaides were conducted. Batch studies indicated that J gIL biomass concentration, initial platinum concentration of 20 mgIL and pH 2 are optimal, while the column studies indicated a flow-rate of! 0 rnL/min and initial platinum concentration of 20 mgIL as optimal. In the platinum effluent study, platinum showed a removal of 23 % and 2 J % for the batch and column studies respectively. Again adsorption was accompanied by //' release. Azalia filiculaides demonstrated its feasibility in the removal of gold and platinum from simulated as well as waste water solutions. Its potential viability as a biosorbent was demonstrated by the high recovery from synthetic solutions of greater than 99% for gold (2-10 mgIL), and greater than 89% for platinum (20 mgIL).

The Nyl River floodplain is one of the jewels in the arid Limpopo Province. The conservation and protection thereof is thus vitally important. The Nyl River Floodplain is an ephemeral floodplain and the largest of its type in South Africa. The wetland is a Ramsar site and provides habitat for a number of endangered species of birds and animals. The aims of this project were to (1) assess the water and sediment quality in the Nyl River system, (2) to determine baseline levels of pollution, (3) to develop a rapid wetland assessment protocol for biomonitoring and (4) to provide a framework for wetland management. Eighteen sites in the Groot Nyl and Klein Nyl rivers, as well as in some of the larger tributaries were selected. Water and sediment were sampled and analyzed to determine metal and nutrient levels. Bacterial analysis also took place at five of the sites along the course of the system. The results obtained from the water analysis indicate that bacterial levels in the system are cause for concern. Although metal levels in the water and the sediment are higher than Target Water Quality and Sediment Guideline Ranges, the metal levels remained relatively constant throughout the system. The metal levels indicated that they pose no potential threat to the system. The comparison between the present and historical ecological state indicated that nutrient levels are increasing in the system. The levels of toxic ammonia did not increase and thus the water quality in the system can thus be classified as fair. The sequential extraction of the sediment indicated that the majority of the metals in the sediment are not readily bioavailable. They were released by the fourth and fifth fractions and will only become available in the presence of strong reducing or oxidizing agents. Organic contaminant levels were also analysed in the sediment. The results indicated traces of PCB’s (Poly-chlorinated Biphenyls) and pyrethroids (Cypermethrin), but concentrations were too low to quantify. iii The third aim of the project was to develop a Wetland Assessment Protocol. A draft version of the protocol was developed using a modified version of the South African Scoring System version 5 (SASS5). Due to the lack of biotopes in the system, the vegetation biotope was chose as sampling habitat. Aquatic invertebrates were collected and a total score was given to each sampling site. The total site rating was determined using a combination of the SASS5 scoring system, a newly developed habitat assessment system and a human impact assessment system, The Wetland assessment protocol identified changes in water quality, but more refinement is required on a system with a greater pollution gradient. The fourth aim of the project was to set up a draft framework for wetland management. The framework is based on the National Estuary Programme of the USEPA. It has been interpreted and adapted for use in wetlands, in a similar way to which USEPA ecological risk assessment guidelines have been adapted for the South African scenario. This research project was thus able to (1) provide baseline values for the Nyl River System, (2) to produce a first draft of a Wetland Assessment Protocol and (3) provide a framework for wetland management. It is envisaged that the information in this thesis will provide useful information in the protection and management of the Nyl River. / Prof. J.H.J. Van Vuren

M.Sc. (Zoology) / The catchment area of the Olifants River is being subjected to increased agricultural and mining activities, industrial development and urbanisation. As a result of this, the water quality 'of the Olifants River and some of its tributaries (e.g. Selati River) has been deteriorating since 1983. This causes reason for concern as one of the downstream water users in the Olifants River catchment is the Kruger National Park, which requires of good quality to sustain its terrestrial and aquatic ecosystems It was therefore necessary to determine what extent activity midstream-or--tlie I Olifants River, especial y in the Phalaborwa area, influenced the water quality of the Olifants River. In this study, an evaluation was done of the water quality (physically and chemically of the Lower Olifants River inside of the Kruger National Park, as well as the Lower Selati River, a tributary of the Olifants River which flows through the Phalaborwa area. Special attention was paid to the metal concentrations in the water, sediment and fish. Water and sediment were sampled every alternate month from April 1990 to February 1992 at six sampling sites along the Lower Olifants River and one in the Selati River. Standard methods were used to determine the physical and chemical characteristics (e.g. pH, TDS, etc.) of the water. The fish species Barbus marequensis was also sampled every alternative month, but only at three sampling sites along the Olifants River and one in the Selati River. Organs and tissues that were dissected, included the gills, fat, liver, gonads, gut, muscle, skin, blood, vertebrae, kidney and bile, as well as the gut contents. In February 1992, additional sampling was performed at Pioneer Dam, a natural reference point used in this study. Atomic absorption spectrophotometry was used in the laboratory to determine the Cr, Cu, Fe, Mn, Ni, Pb, Sr and Zn concentrations in the water, sediment and fish samples. (The water quality of the Selati River was found to be stressful to aquatic life, especially .) with regard to the sodium, fluoride, chloride, sulphate, potassium, total ~dissolved salts 1 and metal concentrations (except strontium). The Selati River also influenced the ': water quality of the Olifants River after the Selati-Olifants confluence. Most of the :. time the water quality of the Lower Olifants River in the KNP did, however, comply With the recommended guideline limits, except for the metal concentrations. The high metal concentrations detected in the water (in some cases sub-lethal levels) indicated some degree of metal pollution, but, due to the hardness of the Olifants River water, conditions were not necessarily toxic to the aquatic life. The accumulated metals in the organs and tissues of marequensis gave a good indication of the metal levels to which the fish were exposed. More metals were taken up by the fish from April 1990 to February 1991 than from April 1991 to February 1992. The various metals were . distributed differently to the tissues of B. marequensis, with the highest zinc concentrations being accumulated by the skin and ovaries; the highest copper and iron by the liver, kidney and gut; the highest chromium and nickel by the blood; and the highest manganese, lead and strontium by the vertebrae and gills. These results afforded guidelines as to the types of tissue which should be sampled as the most suitable for the analysis of the various metals in polluted waters.

M.Sc. (Zoology) / An investigation was made into the presence and uptake of seven selected metals by the organs and tissues of the various developmental stages of the African clawed frog Xenopus laevis from industrial, mine and sewerage polluted aquatic environments on the Witwatersrand. These results were compared with conditions in two relatively unpolluted localities where the clawed frog also occurs. Attention was given to the physical and chemical conditions including the concentration of the metals at various localities. Gut content analyses of the frog stages of the plataona was made to identify the particular food items ingested by the animal but also to correlate this with the incidence of the macro invertebrate organisms present. Metal concentrations were determined for both the gut contents as well as the macro invertebrates as a group at two selected localities. The presence and concentration of various metals were determined in specific organs and tissues of the frog and compared with each other. According to the data the spleen, gallbladder, middle & Hind gut as well as the testes were identified as the target organs containing the highest concentrations of the various metals. Shortcomings in the work is pointed out and recommendations made on possible further research.

M.Sc. / Pollution of the earth is presently one of the most important environmental issues of the world and various attempts, including creation of public awareness have been initiated over the past few years to address this situation. There is especially a global concern about the progressive pollution of valuable freshwater systems which most organisms, including humans, are reliant upon. This includes South Africa's aquatic ecosystems, many of which have been degraded over the past few decades. The Olifants River in Mpumalanga is one of the most threatened river systems in South Africa. It is impacted by various anthropogenic activities, particularly mining in the upper catchment, and urbanisation, industrial and agricultural activities in the upper and lower catchments. Previous investigations have shown that these activities are responsible for the degradation of this river system. The broad objective of this study was to obtain data on water and sediment quality, as well as bioaccumulation of metals in fish via monitoring of the Olifants River. It formed part of a major study concerned with the experimental investigation of lethal and sub-lethal effects of metals on fish physiology, supported by a field investigation into the water quality and metal contamination of the biotic and abiotic components of the Olifants River system. Physico-chemical properties of the water as well as the concentrations of some metals (Al, Fe, Cu, Zn, Ni, Mn, Pb & Cr) in the water and sediment were seasonally investigated. The extent of bioaccumulation of these metals in selected organs/tissues (muscle, gills, liver & skin) of Oreochromis mossambicus and Clarias gariepinus from Loskop Dam (upper catchment) and Mamba Weir, Kruger National Park (lower catchment) was also investigated. High levels of various macro-constituents and metals were detected at many sites in the study area and in many cases they exceeded the guideline limits set for aquatic ecosystems. Localities 2, 3, 6, 8, 10, 12 and 17 were observed to be severely impacted (see Chapter 9- Table 9.1) by elevated concentrations of pollutants influencing variables such as TDS and sulphates. This confirms that these sites are being impacted by mining. This was further confirmed by low pH-values at localities 3, 5, 8, 9, 10 and 12 which indicate on acid mine drainage originating from the many coal mines in the upper catchment of the Olifants River. Nutrient enrichment (elevated levels of phosphates, nitrates and nitrites) occurred at many sites in the catchment but in particular at localities 3, 4, 6, 10, 11, 14, 15 and 17. Point source pollution from sewage treatment works and non-point sources from agricultural runoff and informal settlements are the main contributors to these elevated levels of nutrients. The Selati River, impacted in particular by elevated phosphate levels, is the main contributor to the high nutrient levels detected at locality 17. It is evident from the evaluation of the metal concentrations in the water and sediment (Table 9.2) that most of the sites in the Olifants River catchment are being impacted by metal pollution. Oreochromis mossamhicus and C gariepinus sampled at selected sites in the Olifants River accumulated selected metals in the following order; Fe>Zn>Al>Cr>Ni>Pb>Mn>Cu. Levels were generally high in the liver and gills, while much lower levels were detected in the skin and muscle tissues. Gill tissue is in direct contact with the aqueous environment and therefore gives a good indication of the extent of exposure. Skin tissues usually contained relatively low levels of metals (except for Zn). Although muscle tissues usually accumulated low metal concentrations it is an important tissue to monitor in bioaccumulation studies as it can lead to metal poisoning if contaminated muscle tissues are consumed by humans. Adult specimens were mostly sampled and within this range there was a slight decrease in Cu, Al, Fe, Ni, Mn and Cr concentrations with increasing age. Temporal variation in metal accumulation by fish possibly occurred due to variations in metal concentrations in the water and sediment at a locality. These differences were caused by seasonal variation in climatical conditions (eg. rainfall, temperature), as well as temporal fluctuations of pollutant inputs into the river system. Aquatic organisms at both localities 15 (Loskop Dam) in the upper catchment and 17 (Mamba weir, Kruger National Park) in the lower catchment are at present being chronically exposed to elevated levels of the investigated metals, compared to both the control site and results in literature. The impact of the highly polluted Selati River in the lower catchment was evident in the difference between metal concentrations detected in fish at locality 17, and at locality 19 (Phalaborwa Barrage) upstream of the Olifants-Selati confluence. The present study clearly indicates that the Olifants River is subjected to various sources of pollution which could be detrimental to the health of this aquatic ecosystem. It is recommended (see Chapter 9) that a multi-disciplinary approach including a biomonitoring programme, should be followed to ensure a sustainable freshwater ecosystem.