The escalating pollution of the environment has been one of the greatest concerns of science in recent years. Industrial advances in agriculture, expansion of chemical industries and a general change in lifestyle all over the world has lead to release of a variety of pollutants into the environment, thus contaminating the atmosphere, water bodies and many soil environments. In general, other than some natural processes, soils are increasingly being contaminated by anthropogenic sources such as leakages from waste containment facilities, accidental spills and industrial operations. Apart from affecting biotic components of the ecosystem, these pollutants greatly affect the performance, behavior and stability of the soil ecosystem, these pollutants greatly affect the performance, behavior and stability of the soil systems, thus causing severe damage to structures founded on them. The hydraulic and/or chemical alterations which allow these polluting substances to move within soil pores lead to physico-chemical decomposition processes, chemical alterations, leaching and ion exchange reactions. Such reactions could also result from natural processes such as weathering; but the effects caused by pollutants occur at faster rates. Soils are composed of clays, silts and sands. Due to charged nature of the particles and their large specific surface, engineering properties of clays are greatly affected by pollutants. The magnitude of these effects can vary significantly depending on the type of soil, the type and concentration of contaminant, duration of interaction and the environmental conditions. Hence, an understanding of contaminant-clay interactions is important for prevention of geotechnical features, if possible, or at least for planning of remedial measures. Understanding these effects and planning remedial measures requires measurement of the affected properties of polluted soils. This may involve the modification of standard test procedures or the development of new test procedures. The main types of contaminants include inorganic acids, alkalis, sulphates, organic contaminants, toxic or phytotoxic metals and combustible substances. All of these are widely used in industries. While the adverse effects of presence of sulphate in alkaline conditions is well known, little information is available on the effect of sulphate in natural soils under acidic environments. Sulphuric acid is widely employed in the production of fertilizers, pharmaceuticals, pigments, rayon, film, iron, steel, explosives, paper and paper industry. It is also used in cleaning, etching, petroleum refining, electroplating, metallurgy, and in lead-acid batteries. Due to its widespread but often improper usage and the difficulty in safe storage, sulphuric acid is often found as a contaminant in natural soils. Sulphuric acid is also generated in natural soils by oxidation by pyrites in the presence of atmospheric oxygen. Hence, an attempt has been made in this thesis to study the behavior of soils containing different clay minerals during acid-sulphate interaction. The effect of sulphate on soils containing calcite, whose presence is quite common, has also been studied. A review of literature suggests that most common geotechnical failures due to contamination occur due to significant changes on the volume change behavior. Also, it is known that severe changes that occur in soil properties can essentially be attributed to mineralogical changes that occur during interaction with pollutants. Therefore, volume change behavior of soil and detailed mineralogical changes and the consequent morphological changes that occur in soils with acid sulphate are studied.

High concentrations of arsenic are found near gold-mine tailings. The most common form of arsenic found in soil is arsenate, which is a known toxicant. We used the standardised earthworm reproduction test for the species Eisenia andrei (E. andrei) to study the toxicity and bioavailability of arsenic-contaminated soil. Arsenic is toxic to earthworms as indicated by the decrease in survival and reproduction. Arsenic-spiked artificial soil was more toxic than arsenic-spiked field soil based on total arsenic concentration in soil. Moreover, soil from near mine tailings showed a reduced toxic effect despite its high soil arsenic concentration as compared to spiked field soil. Measurements of arsenic tissue concentrations in the earthworm indicated that uptake of arsenic into earthworm tissue was higher in spiked artificial soil as compared to spiked field soil and that the maximal body burden was 396 mug As/g dry tissue weight. However, when considering tissue arsenic concentration, spiked field soil is more toxic than spiked artificial soil. Therefore the tissue rather than soil content may better reflect the magnitude of arsenic toxicity to E. andrei.

This thesis is part of a broader project that examines three different approaches to evaluating trace metal contamination in urban brownfields: the measure of total soil metals; calculating bioavailable metals; and the use of species as bioindicators of trace metals in soils. Chapter 1 discusses the problems inherent in each approach such as; inconsistent results due to differences in techniques, extrapolation from laboratory to field, and the influence of species differences and environmental conditions. Chapter 2 is a site description measuring biodiversity, community structure and activity of three urban brownfields. The site description was used to select organisms that were subsequently evaluated for their usefulness as bioindicators of trace metals (chapter 3). Of the three plant species used (dandelion, bladder campion, and chicory), dandelion has the possibility of being a suitable bioindicator of Cd, Ni, and Zn, while bladder campion may be suitable for evaluating Cd, Ni, Pb, and Zn.

No abstract available. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2002.

The temporal fate of selected parameters, including redox potential; pH; phenol; nitrates; sulphates; copper and zinc, of a young synthetic acetogenic phase landfill leachate was assessed by perfusing a series of sequential soil (Hutton) microcosms (arrays) at two hydraulic loading rates (HLR). We chose HLRs that were representative of areas in South Africa with typically elevated rainfall (Pietermaritzburg – HLRh) and one with relatively low rainfall (Kimberley – HLRl). Preliminary phenol, copper, and zinc adsorption investigations on gamma radiation sterilized soil and unsterilized soil revealed superior adsorption rates for each compound in the unsterilized soil. This revealed the importance of the biological component of soil in phenol, copper, and zinc attenuation in soil. The results presented in this thesis suggest that the HLR of leachate into soil arrays contributes to significant differences in the fate of the landfill leachate parameters mentioned earlier. In addition, we assessed the temporal and spatial succession of bacterial community diversity in each of the soil arrays by polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). Prior to this, we compared two soil DNA isolation techniques, the modified method of Duarte et al. (1998) (Bead Beat) and the commercial Mo-Bio UltraClean™ Soil DNA isolation kit (Kit). The DNA isolated by the Kit method was significantly superior regarding purity and absence of DNA fragmentation. However, the Bead Beat method produced a significantly higher yield per reaction before further purification with Wizard™ Clean-Up columns produced DNA extracts of similar purity at the cost of a significant reduction in DNA yield. The Kit method was chosen for future DNA isolation and PCR-DGGE based on the quality of the PCR amplicons generated from the Kit isolated DNA. PCR-DGGE was further optimized by comparing the efficiency and sensitivity of a silver stain against ethidium bromide. Silver stain generated DGGE gels with greater number of bands (species richness – S) and stronger band signal intensities. Captured DGGE fingerprints generated data that were subjected to the Shannon-Weaver Index (H’) and the associated Shannon-Weaver Evenness Index (EH) to measure the change in spatial and temporal bacterial diversity. There was a significant shift in S and H’ for both HLRs but a significant change in EH was only observed for HLRh. Furthermore, a temporal comparison of S and H’ between both HLRs revealed significant differences throughout the investigation. Canonical Correspondence Analysis (CCA) revealed spatial distribution of bacterial community diversity with depth. Effects of phenol concentration, redox potential, and pH of the effluent leachate on bacterial community diversity was tentatively assessed by three-dimensional graphical representation on PlotIT 3.2 software. Bacterial community diversity showed a decrease with elevated pH and phenol concentration along with decreasing redox potentials for both HLRs. While this study reveals the spatial and temporal dynamics of bacterial community diversity in situ, it provides important evidence with respect to: (i) the effects of rainfall / leaching rates (HLR) on spatial and temporal bacterial community succession; (ii) the importance of the biological component in natural attenuation; (iii) the ability of soil, previously unexposed to landfill leachate, to initiate natural attenuation of phenol and other leachate constituents; (iv) the capacity of PCRDGGE to fingerprint successional changes in bacterial community diversity, (v) and the potential to clone and sequence selected members of bacterial associations for future reference in environmental remediation strategies. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

The industrial port of Richards Bay on the eastern seaboard of KwaZulu-Natal, South Africa has undergone rapid growth over the last 25 years. This industrial growth has inevitably led to an increase in the anthropogenic pollutant inputs in the area. However, the degree of this contamination has not previously been assessed not been accompanied by an awareness of its environmental impacts. This project serves to assess the current environmental situation of the area and provide background levels against which the environmental impacts of further growth in the area can be assessed. The main pollution point sources in the area were identified as a pulp and paper plant, a sulfuric acid/fertiliser plant and aluminium smelters. The chemical and physical processes involved within these industries were identified and discussed in detail. The common inorganic pollutants emitted by these industries were identifies as trace metals, sulfur dioxide, NOx gases and fluoride. It was these pollutants that therefore became the focus of this study. Reservoirs within Richards Bay that may become sinks for contamination were identified and water, sediment and soil samples were taken from these reservoirs. The samples were analysed for trace metal contamination, pH, alkalinity and fluoride levels. Analysis of the acidity and alkalinity of water, sediment and soils samples demonstrated that there is presently no long-term acidification of the environment in Richards Bay. The only samples that showed increased acidity were the soils taken from the roadside sites immediately outside the industries. This lack of overall acidification indicates that, at present, there are no detrimental effects of acidic emissions on the hydrosphere and geosphere. Only cursory investigations were conducted into the fluoride levels found in water samples. None of the samples analysed demonstrated detectable amounts of fluoride present. Comprehensive trace metal analyses were performed on the water, sediment and soil samples through the use of ICP-AES. Levels obtained were compared with levels from samples taken from relatively uncontaminated background sites. Trace metal analysis indicated contamination of the freshwater reservoirs when compared with the background, while the soils and saltwater reservoirs remain largely uncontaminated. However, the contaminated areas did not show levels greater than quality guideline concentrations. Further studies should be conducted with regards to the trace metal contamination of the biosphere and the bioavailability of the contaminants already present in the waters, sediments and soils. More detailed investigations should also be conducted into the levels of atmospheric pollutants and fluoride levels in all reservoirs. / Thesis (M.Sc.) - University of KwaZulu-Natal, Pietermaritzburg, 2004.

Scopo del progetto era valutare lo stato di salute e la qualità dei suoli agricoli lombardi e di alcune sue aree caratterizzate da specifiche criticità ambientali, attraverso un monitoraggio multidisciplinare. L’uso di indicatori biologici accoppiato alle classiche tecniche analitiche ha consentito di implementare le informazioni ottenute dal punto di vista chimico-fisico. Contrariamente al passato infatti, la componente vivente del suolo è diventata fondamentale alla comprensione delle sue condizioni, in quanto esso è stato riconosciuto come sistema strettamente connesso agli altri comparti ambientali, influenzato e caratterizzato da tutti gli organismi che lo compongono. Sulla base di ciò sono state indagate la struttura e le caratteristiche delle comunità microbiche, dei lombrichi e dei protozoi ciliati, le attività enzimatiche del suolo, e la genotossicità delle sostanze inquinanti utilizzando il trifoglio come pianta indicatrice. Abbiamo inoltre avuto modo di applicare alcune tecniche che esulano dal classico monitoraggio, ma che forniscono informazioni preziose circa il comportamento di una sostanza o di un elemento. Si tratta dell’applicazione della diluizione isotopica per determinare la presenza del cromo esavalente in suoli potenzialmente contaminati, e di biosaggi con batteri bioluminescenti per valutare la biodisponibilità di arsenico e mercurio in un Sito di Interesse Nazionale. / The aim of the project was to assess health status and quality of agricultural soils of the Lombardia region, and some areas with critical environmental situations, through a multidisciplinary monitoring. The use of biological indicators coupled to classic analytical techniques, has allowed the implementation of the information obtained from the chemical-physical point of view. Contrary to the past, the living component of the soil has become crucial to better understand its condition, as it has been recognized as a system closely related to other environmental media, influenced and characterized by all organisms that compose it. Basing on this it was investigated the structure and characteristics of microbial communities, earthworms and ciliated protozoa, the enzymatic activities of the soil, and the genotoxicity of pollutants using clover plants as indicator. We also had the opportunity to apply some of the techniques that are outside the classic monitoring, but that can provide valuable information about the behavior of a substance or an element. These techniques are: the application of isotope dilution to determine the presence of hexavalent chromium in potentially contaminated soils, and bioassays with bioluminescent bacteria to assess the bioavailability of arsenic and mercury in a Site of National Interest.

Os elementos potencialmente tóxicos (EPTs) estão presentes nos solos em concentrações dependentes do material de origem e das ações antrópicas. A adição de EPTs ao solo pelas atividades antrópicas pode ocasionar risco à saúde humana, já que estes elementos podem ser acumulados no organismo por meio do contato dérmico com o solo, da inalação de partículas em suspensão, de ingestão de solo e de alimentos contaminados. A contaminação dos alimentos ocorre pelo cultivo em áreas com alta biodisponibilidade de EPTs, e nessa condição ocorre absorção e translocação para a parte aérea, com possível acúmulo dos metais nas porções comestíveis, como raízes, frutos e grãos. A biodisponibilidade dos EPTs é regulada pelas características químicas dos elementos e por atributos do solo, como a CTC, o pH e a matéria orgânica (MO). Sintomas de toxicidade e alterações morfológicas e fisiológicas podem aparecer dependendo da absorção e da movimentação dos EPTs nas plantas. Objetivou-se neste trabalho avaliar o efeito da adição de bário (Ba), de cádmio (Cd), de cobre (Cu), de níquel (Ni) e de zinco (Zn) em amostras de um Neossolo Quartzarênico e um Latossolo Vermelho distrófico, sob duas condições de saturação por bases (30% e 50 ou 70%, dependendo da cultura), no cultivo de arroz (Oryza sativa), alface (Lactuca sativa), girassol (Helianthus annuus) e tomate (Solanum lycopersicum). Os EPTs nos solos foram extraídos com EPA 3051a, Água Régia, DTPA, Mehlich 1, Mehlich 3, HNO3 (0,43 mol L-1) e CaCl2 (0,01 mol L-1), e seus teores correlacionados com os presentes nas raízes, na parte aérea, nos frutos e com a quantidade acumulada pelas plantas. Os fatores de bioconcentração (FBC) e de transferência (FT) foram calculados para as culturas. O índice SPAD (Soil Plant Analysis Development - Chlorophyll Meter) foi determinado na fase vegetativa da alface, do arroz e do girassol, enquanto a atividade fotossintética foi determinada pelo IRGA (Infrared gas analyzer). Os maiores teores de EPTs foram observados nas plantas cultivadas no Neossolo. As quantidades de Cu, Ni e Zn acumuladas nas plantas apresentaram correlação positiva com os teores extraídos pelo EPA 3051a e pela Água Régia. Os teores extraídos com HNO3 (0,43 mol L-1) apresentaram elevada correlação positiva com os teores reativos extraídos com DTPA e com Mehlich 3, e também com as quantidades de EPTs acumuladas pelas plantas. Os FBCs foram mais altos nos solos com baixa CTC, baixos teores de MO e baixos valores de pH. O arroz apresentou a menor translocação de Cd do sistema radicular para os grãos. O Cu, o Ni e o Zn causaram alterações no desenvolvimento da alface e do girassol, e diminuíram a transpiração e a condutância estomática da alface. O arroz apresentou a menor absorção de EPTs e a maior tolerância ao Ba, ao Cd, ao Ni e ao Zn, no entanto, as plantas apresentaram maiores condutividade estomática e transpiração. / The concentration of potentially toxic elements (PTEs) in the soil depends on the parent material and human actions. The addition of PTEs to the soil through human activities may pose a risk to human health, as these metals can accumulate in the body when the skin is exposed to contact with soil, or particulate matter is inhaled; or soil and contaminated food are ingested. Food contamination occurs in areas where there is high bioavailability of PTEs, which can be absorbed by plants and translocated to the shoot, with possible metal accumulation in edible portions, such as roots, fruits and grains. The bioavailability of PTEs is governed by the chemical characteristics of the elements and by certain soil attributes, such as CEC, pH and organic matter (OM). Symptoms of toxicity and morphological and physiological changes may appear depending on the absorption and movement of PTEs in plants. The aim of this study was to evaluate the effect of barium (Ba), cadmium (Cd), copper (Cu), nickel (Ni) and zinc (Zn) in samples of an Entisol and an Oxisol under two conditions of base saturation (30% and 50% or 70%, depending on the culture) in the cultivation of rice (Oryza sativa), lettuce (Lactuca sativa), sunflower (Helianthus annuus) and tomato (Solanum lycopersicum). Contents of PTEs in soils were extracted with EPA 3051a, Aqua Regia, DTPA, Mehlich 1, Mehlich 3, 0.43 M HNO3 and 0.01 M CaCl2, and their levels were correlated with the PTEs levels in roots, in shoots, in fruits and with the amount accumulated by plants. The bioconcentration factor (BCF) and the transfer factor (TF) were calculated for the cultures. The SPAD index (Soil Plant Analysis Development - Chlorophyll Meter) was determined at the vegetative stage of lettuce, rice and sunflower, while photosynthetic activity was determined by IRGA (Infrared gas analyzer). The highest PTEs contents were observed in plants grown in the Entisol. Amounts of Cu, Ni and Zn accumulated in plants were positively correlated with the contents extracted by EPA 3051a and the Aqua Regia. The contents extracted with 0.43 M HNO3 had high positive correlation with the concentration extracted with DTPA and Mehlich 3, and with the amount of PTEs accumulated by plants. The BCFs were highest in soils with low CEC, low OM content and low pH values. Rice had the least translocation of Cd from the root to the grain. Cu, Ni and Zn caused changes in the development of lettuce and sunflower, and decreased transpiration and stomatal conductance of lettuce. Rice had the lowest PTEs absorption and the highest tolerance to Ba, Cd, Ni and Zn, however, the plants had greater stomatal conductance and transpiration.

This study focuses on determining the quality of soil and groundwater at the Onderstepoort Municipal Solid Waste (MSW) landfill site. The study area is situated in Pretoria North, a jurisdiction of City of Tshwane Metropolitan Municipality (CTMM). Samples were collected from three different spheres (i.e. leachate, soil and water) in the study area, to determine the concentration of metals accumulated in each sphere. The three spheres provided an overview of the contaminants found in leachate, soil and water. The laboratory analyses using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) indicated that soils in the site have been severely contaminated with heavy metals. Higher concentrations of heavy metals occurred in the soils compared to the groundwater surrounding the landfill site and this may be due to the ability of the soil strata to absorb the contaminants caused by the landfill leachate. In essence, the measurements indicated that leachate soil has very high pollutant levels (0.21 to 2505.61 mg/kg); soil was characterised by fairly-high pollutant levels (0.03 to 638.27 mg/kg); leachate solution has given rise to moderate pollutant levels (0.01 to 2.296 mg/L) and water resources have low-moderate pollutant levels (<0.0001 to 0.456 mg/L) depending on the location. Furthermore, the findings indicated that the soil was contaminated with lead, cadmium, copper, zinc and nickel, and the concentration increases particularly where the generation of leachate is taking place. Groundwater, particularly in Borehole 2 has been moderately contaminated with nitrite, calcium and manganese. The findings also indicated that the concentrations of contaminants become high in borehole located close to the waste dump and decrease further away from the waste dump. The chemical analysis of this groundwater indicated that the concentrations of chemical properties have increased since the year 2009. This was determined through the comparison of groundwater study undertaken in 2009 to the current study results obtained. The site geological formation, Rustenburg Layered Suite is known to contain the anomalies of nickel, chromium, vanadium, copper, arsenic, lead and zinc but these are less toxic and less distributed. Therefore, the primary source of pollution at the study area could be the landfill operation through the generation of leachate affecting both soil and water / College of Agriculture and Environmental Sciences / M. Sc. (Environmental Sciences)

Made available in DSpace on 2014-06-11T19:26:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-22Bitstream added on 2014-06-13T19:33:41Z : No. of bitstreams: 1 jesus_ls_me_bauru_prot.pdf: 14176477 bytes, checksum: 1b3c89c43f22dd709d61a808988b4abe (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Para a avaliação da contaminação dos solos em áreas de disposição de resíduos sólidos é fundamental conhecer a permeabilidade desses solos, quantificada pela condutividade hidráulica (k). Pesquisas anteriores avaliaram a contaminação que ocorre no Aterro de Resíduos Sólidos Urbanos de Bauru/SP, e sugerem valores de K para os solos que ocorrem no local. O objetivo desta pesquisa é dar continuidade aos estudos de investigação neste aterro, buscando encontrar valores representativos de K para os diferentes tipos de solos que ocorrem na área, empregando técnicas de ensaios em campo e laboratório. No laboratório foram realizados ensaios de condutividade hidráulica em permeâmetros de parede rígida e flexível a carga variável e constante em amostras indeformadas. Em campo, foram conduzidos ensaios de recuperação em poços de monitoramento (Slug Test), zona saturada, e ensaios de condutividade com o permeâmetro de Guelph na zona não saturada. Quatro tipos de solos são encontrados na região do aterro, coluvião, aluvião e residual de arenito. No laboratório, utilizando permeâmetros de parede rígida, foi possível encontrar valores médios de K para o colúvio e o alúvio, sendo estes, respectivamente, k=2,6x10-6, 2,0x10-5 m/s. Paro o solo residual e para o arenito utilizou-se de permeâmetros de parede flexível para a realização dos ensaios, com saturação por contra pressão, obtendo-se os valores de k=1,2x10-7 e 3,3x10-8 m/s, respectivamente. No campo para o solo residual encontraram-se valores de K de 3,7x10-7 m/s na zona saturada e de 3,4x10-7 e 1,3x10-7 m/s para a zona não saturada. No solo coluvionar obteve-se um valor de K de 5,3x10 na zona não saturada. No aluvião encontrou-se grande variação de K com a profundidade, obtendo-se um valor médio para a zona saturada d 7,9x10-7 m/s. Já, para... / In the assessment of soil contamination caused by solid waste disposal sites it is essential to investigate the soils permeability, quantified by the hydraulic conductivity (k). Previous research has assessed the contamination that occurs in the Brazil/SP Municipal Solid Waste disposal site, and suggested K values for the soils that occur at this site. The objective of this research is to continue the investigation studeies at the site, aiming to find representative K values for all the different soil types that occur in the area, using both laboratory and in situ testing techniques. Laboratory hydraulic conductivity tests were performed in rigid and flexibe wall permeameters by variable and constant head on undisturbed soil samples. Slug Tests in monitoring wells (saturated zone) and hidraulic conductivity tests with the Guelph permameter (unsaturated zone) were carried out in situ. Four types of soils are found in the site: colluvium, alluvium, sandstone and residual sandstone. The average K values for the colluviam and alluvium determined in the rigid wall permeameter were qual to 2.6x10-6 and equal to 2.0x10-5 m/s, respectively. The flexibe wall permeameter was used to carry out lab tests in the residual soil and sandstore, using backpressure saturation, obtaining the K values equal to 1.2 x 10-7 and equal to 3.3x10-8 m/s, respectively. A K value of 3.7x10-7 m/s for the residual soil was determined in situ in the saturated zone and K values of 3.4x10-7 and 1.3x10-7 m/s were determined in the unsaturated zone. For the colluvium soil, a K value of 5.3x10-6 m/s in the unsatured zone was determined. The K values varied with depth in the Alluvium, and the average valeu for the saturated zone was 7.9x10-7 m/s. It was not possible to carry out in situ tests in the residual soil. The representative K value were equal to 5.3x10-6, 1.1x10-4 and 1.2x10-7... (Complete abstract click electronic access below)