Orientador: Carmem Silvia Fontanetti Christofoletti / Banca: Maria Aparecida Marin Morales / Banca: Tatiana da Silva Souza / Banca: Roberta Cornelio Ferreira Nocelli / Banca: Valdemar Luiz Tornisielo / Resumo: A degradação de solos provocada pelo mau gerenciamento das atividades humanas consiste em uma constante e crescente preocupação. O tratamento adequado e disposição final do grande volume de resíduos urbanos, industriais e agrícolas produzidos diariamente são um grande desafio à comunidade científica. Neste sentido, vem sendo pesquisadas inúmeras alternativas para o aproveitamento e destinação ambientalmente segura de tais resíduos, dentre as quais se destaca a aplicação destes como fertilizantes agrícolas. Tendo isso em vista, o presente trabalho teve por objetivo simular a dose de aplicação em cultura de cana-deaçúcar, de amostras de lodo de esgoto primário, biossólido e vinhaça de cana-de-açúcar, de acordo com a legislação brasileira vigente, e verificar seus potenciais tóxico, citotóxico, genotóxico e mutagênico, tanto das amostras brutas quanto de combinações destas com amostras de solo controle, antes e após o seu bioprocessamento por diplópodos. As amostras foram analisadas antes da exposição à diplópodos, designado por tempo 0 (t0 - momento da mistura) e após o bioprocessamento destas pelos animais (t30 - 30 dias após a exposição aos diplópodos). As análises químicas das amostras demonstraram diferentes concentrações de metais e macro/micronutrientes, evidenciando o bioprocessamento destes resíduos pelos animais. Para avaliar a toxicidade das diferentes combinações dos resíduos foram avaliadas a taxa de mortalidade e o comportamento dos indivíduos, e realizadas análises histológicas, histoquímicas e ultra-estruturais do intestino médio dos diplópodos, após 7, 30 e 90 dias de exposição. Os resultados obtidos nas avaliações histológica, histoquímica e ultra-estrutural, evidenciaram a toxicidade dos resíduos, observada por diferentes alterações como aumento nas taxas de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The soil degradation caused by poor management of the human activities comprises a constant and growing concern. The proper treatment and final disposal of large volumes of industrial and agricultural wastes daily-produced are a big challenge to the scientific community. In this sense, several alternatives for the environmentally safe use and disposal of such waste have been studied, among which stands out the application as an agricultural fertilizer. Keeping this in view, the present study aimed to simulate the primary sewage sludge, biosolid and sugar-cane vinasse application rate in sugar-cane culture, according to the Brazilian legislation and checking their toxic, cytotoxic, genotoxic and mutagenic potential of both crude samples and combinations thereof with control soil samples, before and after its bioprocessing by diplopods. The samples were analyzed before exposure to diplopods, designated as time 0 (t0 - time of mixture) and after being bioprocessed by these animals (t30 - 30 days after diplopod‟s exposure). The samples chemical analysis showed different concentrations of metals and macro/micronutrients, making evident the residues bioprocessing. Diplopods‟ behavior and mortality rate were evaluated to assess the toxicity of different residues combinations, as well as the histology, histochemistry and ultra-estructure of diplopods midgut after 7, 30 and 90 days of exposure. The results obtained in the histological, histochemical and ultra-estructural evaluations demonstrated the waste toxicity. It was observed through several changes, like increased epithelial renewal rates, thickening of the brush border, accumulation of cytoplasmic granules in the hepatic cells and hemocytes grouping among hepatic cells, indicating severe inflammation, seeing that they were still observed the presence hepatic... (Complete abstract click electronic access below) / Doutor

Made available in DSpace on 2014-06-11T19:30:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-05-27Bitstream added on 2014-06-13T18:41:11Z : No. of bitstreams: 1 christofoletti_ca_dr_rcla.pdf: 1823672 bytes, checksum: 96f09ae686b3513bc6d298098fed20c7 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A degradação de solos provocada pelo mau gerenciamento das atividades humanas consiste em uma constante e crescente preocupação. O tratamento adequado e disposição final do grande volume de resíduos urbanos, industriais e agrícolas produzidos diariamente são um grande desafio à comunidade científica. Neste sentido, vem sendo pesquisadas inúmeras alternativas para o aproveitamento e destinação ambientalmente segura de tais resíduos, dentre as quais se destaca a aplicação destes como fertilizantes agrícolas. Tendo isso em vista, o presente trabalho teve por objetivo simular a dose de aplicação em cultura de cana-deaçúcar, de amostras de lodo de esgoto primário, biossólido e vinhaça de cana-de-açúcar, de acordo com a legislação brasileira vigente, e verificar seus potenciais tóxico, citotóxico, genotóxico e mutagênico, tanto das amostras brutas quanto de combinações destas com amostras de solo controle, antes e após o seu bioprocessamento por diplópodos. As amostras foram analisadas antes da exposição à diplópodos, designado por tempo 0 (t0 – momento da mistura) e após o bioprocessamento destas pelos animais (t30 – 30 dias após a exposição aos diplópodos). As análises químicas das amostras demonstraram diferentes concentrações de metais e macro/micronutrientes, evidenciando o bioprocessamento destes resíduos pelos animais. Para avaliar a toxicidade das diferentes combinações dos resíduos foram avaliadas a taxa de mortalidade e o comportamento dos indivíduos, e realizadas análises histológicas, histoquímicas e ultra-estruturais do intestino médio dos diplópodos, após 7, 30 e 90 dias de exposição. Os resultados obtidos nas avaliações histológica, histoquímica e ultra-estrutural, evidenciaram a toxicidade dos resíduos, observada por diferentes alterações como aumento nas taxas de... / The soil degradation caused by poor management of the human activities comprises a constant and growing concern. The proper treatment and final disposal of large volumes of industrial and agricultural wastes daily-produced are a big challenge to the scientific community. In this sense, several alternatives for the environmentally safe use and disposal of such waste have been studied, among which stands out the application as an agricultural fertilizer. Keeping this in view, the present study aimed to simulate the primary sewage sludge, biosolid and sugar-cane vinasse application rate in sugar-cane culture, according to the Brazilian legislation and checking their toxic, cytotoxic, genotoxic and mutagenic potential of both crude samples and combinations thereof with control soil samples, before and after its bioprocessing by diplopods. The samples were analyzed before exposure to diplopods, designated as time 0 (t0 – time of mixture) and after being bioprocessed by these animals (t30 – 30 days after diplopod‟s exposure). The samples chemical analysis showed different concentrations of metals and macro/micronutrients, making evident the residues bioprocessing. Diplopods‟ behavior and mortality rate were evaluated to assess the toxicity of different residues combinations, as well as the histology, histochemistry and ultra-estructure of diplopods midgut after 7, 30 and 90 days of exposure. The results obtained in the histological, histochemical and ultra-estructural evaluations demonstrated the waste toxicity. It was observed through several changes, like increased epithelial renewal rates, thickening of the brush border, accumulation of cytoplasmic granules in the hepatic cells and hemocytes grouping among hepatic cells, indicating severe inflammation, seeing that they were still observed the presence hepatic... (Complete abstract click electronic access below) / FAPESP: 09/50578-3

Resumo: O desenvolvimento econômico e a necessidade de proporcionar melhor qualidade de vida a toda a população, constituem alguns aspectos responsáveis para que a produção de residuos sólidos seja cada dia maior, aumentando a necessidade da busca de soluções ambientais corretas, para sua destinação. A compostagem consiste em importante ferramenta para o tratamento da fração orgânica dos resíduos sólidos, através do uso de tecnologias que processam os resíduos originados da agricultura, agroindústria, silvicultura, dos domicílios e, ainda, do loda da estação de tratamento de esgoto, adequando-os para serem incorporados ao solo e contribuindo para redução de adubos químicos. No Brasil, o emprego do processo de compostagem, é ainda bastante restrito, pelo alto grau de empirismo utilizado no controle e avaliação do processo e por falta de conhecimento técnico. Este estudo aborda o problema do tratamento de resíduos sólidos orgânicos provenientes das estações de tratamento de esgoto, através de pesquisa experimental de co-compostagem com outros resíduos orgânicos. No processo desenvolvido, denominado de método respirométrico, utilizou-se metodologia na qual os parâmetros de degradação biológica dos resíduos são quantificados na fase gososa. Os parâmetros avaliados, nesse trabalho, na fase gasosa de processos de co-compostagem do lodo de esgoto, possibilitaram a determinação do consumo de O2 e a geração de CO2 e da demanda bioquímica de oxigênio (DBO). Ao obter valores em substância totalmente homogênia, seu emprego apresentou como vantagens maior representatividade, precisão e confiabilidade, representando uma evolução quando comparados aos métodos tradicionais, permitindo o acompanhamento "on line" e contínuo. Os resultados foram muito superiores, quando... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Economic development and the need to provide better quality of life for the entire population, are responsible for some aspects of the production of solid waste each day is greater, increasing the need to search for environmental solutions right to your destination. Composing is an important tool for the treatment of the organic fraction of solid waste throgh the use of technologies that process the waste generated from agriculture, agribusiness, forestry, households, and also sludge from sewage treatment plant, adapting them to be incorporated into the solid and contribuing to reduction of chemical fertilizers. In Brazil the use of traditional composting process is still very limited, the high degree of empirism used in the control and evaluation of the process and lack of technical knowledge. This study addressed the problem of the treatment of organic solid waste from the sewage treatment plants, through experimental research of co-composting with other organic waste. In the process developed, called respirometric method was used methodology in which the parameters of biological degradation of waste are quantified in the gas phase. The parameters evaluated in this study, in the gas phase of the co-composting of sewage sludge, allowed the determination of O2 consumption and CO2 generation and biochemical oxygen demand (BOD). By obtaining values in totally homogeneous substance, its use had advantages as greater representation, accuracy and reliability, representing an evolution when compared to traditional methods, enabling monitoring "on line" and continuous. The results were far superior when compared to the traditional method, obtaining data lines 1440/day, while in the conventional process, these data are sun up to a daily measurement of temperature, which makes the respirometric method an... (Complete abstract click electronic access below) / Orientador: Rosane Aparecida Battistelle / Coorientador: Jorge Akutsu / Banca: Erich Kellner / Banca: Adilson Renofio / Mestre

Resumo: O estudo objetivou pesquisar a aplicabilidade de métodos alternativos para amenizar o problema da disposição dos resíduos sólidos urbanos. Especificamente nesse trabalho os objetivos foram direcionados no sentido de desenvolver esforços para viabilizar a reciclagem e o reaproveitamento de materiais, medidas essas, que aumentarão a vida útil dos aterros sanitários. Além disso, procuramos fazer um trabalho de Educação Ambiental para a população envolvida, em uma tentativa de incentivar uma mudança de hábitos. Para tanto, foi selecionado um bairro da cidade de Rio Claro (SP), como um projeto-piloto, onde foram observados os obstáculos e os procedimentos acertados, para uma aplicação em futuros projetos. / Abstract: The study aimed to research the applicability of methods to reduce the problem of the arrangement of the urban solids residues. Especially in this research, the objectives were to try hard to turn viable the recycling and the reuse of the materials, step that will extend the useful life of the sanitaries landfills. Moreover, we try to do a work to persuade the envolved population to change of the habits. For this, it's selected a district of the Rio Claro's town, like a pilot plan, wich observed the obstacles and the corrects actions, for a application in futures plans.

Orientador: Maura Seiko Tsutsui Esperancini / Banca: Maria Aparecida Mourão Brasil / Banca: João Luis Cardoso / Resumo: O presente trabalho de pesquisa tem por objetivo determinar o potencial de geração de energia a partir do aproveitamento de resíduos industriais como casca e pó de madeira em uma indústria do setor florestal, que produz painéis de madeira aglomerada, localizada no município de Botucatu, Estado de São Paulo e determinar a viabilidade econômica da aquisição de um equipamento para geração de energia térmica a partir destes resíduos. Esta alteração de processo tem como finalidade gerar economias na aquisição de insumos energéticos adquiridos no mercado e contribuir para a expansão da base de geração de energia da indústria. Os dados para a quantificação dos resíduos gerados no processo industrial, disponíveis para fornecimento de energia térmica na empresa, foram coletados junto à empresa analisada e, a partir de amostras coletadas em julho de 2002, o poder calorífico dos resíduos casca e pó de madeira foi determinado junto ao Laboratório do Departamento de Física e Biofísica do Instituto de Biociências da UNESP de Botucatu/SP. Como o aproveitamento destes resíduos demanda a alteração do sistema de troca de calor, foram descritos o sistema de troca de calor existente e a proposta de alteração deste sistema, que pode funcionar à base de diferentes proporções de resíduos industriais (casca e pó de madeira), além da necessária aquisição de cavaco de costaneira, para aumentar a eficiência do processo de combustão de resíduos. Para a determinação do potencial de geração de energia foi utilizado o conceito de poder calorífico em duas condições de uso para o novo sistema de troca de calor: a alternativa de uso 1, que utiliza as seguintes proporções de resíduos: 50% de casca e 50% de cavaco, e a alternativa de uso 2, que utiliza a seguinte proporção de energia por resíduo: 30% da casca, 30% do cavaco e 40% do pó. Para a análise econômica... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present research had the objective to determine the potential of energy generation with use of industrial residues as bark and saudust of wood in an industry of the forest section, which produces particleboards, located in the municipal district of Botucatu, State of São Paulo and to determinate the acquisition economical viability of an equipment for generation of thermal energy starting with residues. This process alteration had as purpose to generate savings in the acquisition of acquired energy inputs in the market and to contribute to the expansion of the industry energy generation. Data for the residues quantification generated in the industrial process, available for supply of thermal energy in the company were collected in the analyzed company, starting from samples collected in July of 2002, the heat of combustion of the residues bark and saudust of wood were determined in the Laboratory of Physics and Biophysics Department of the Biochemistry Institute of UNESP, Botucatu/SP. As the use of these residues demand the alteration of change of heat system, the change of heat system and the proposal of alteration of this system were described, which can work in different proportions of industrial residues (bark and saudust of wood), besides the necessary acquisition of slab shavings, to increase residues combustion process efficiency. For generation of energy potential determination, the concept of heat of combustion was used in two use conditions for the new system of change of heat: the alternative of use 1, which uses the following residues proportions: 50% of bark and 50% of chips, and the alternative of use 2, which uses the following proportion of energy for residue: 30% of bark, 30% of chips and 40% of saudust. For the economical use analysis the following indicators of economical viability were used: the Liquid Present Value... (Complete abstract click electronic access below) / Mestre

The current energy crisis is exponentially growing and widening the chasm between demand and supply. Biofuels such as ethanol not only provide greener alternatives to fossil fuels but have been shown to reduce emissions from vehicles, improving air etc. Biofuel production from sources such as cellulose is believed to be more sustainable due to its low cost, vast availability in nature and sources such as industrial plant waste can be put to good use. However, due to the absence of a low-cost technology to overcome its recalcitrance, a concept called Consolidated Bioprocessing (CBP) has been put forward which proposes to integrate the production of saccharolytic enzymes, hydrolysis of the carbohydrate components to sugar molecules, and the fermentation of hexose and pentose sugars to biofuels into a single process. The present study involves development of cellulolytic E. coli strains towards cellodextrin assimilation by employing an energy-saving strategy in cellulose metabolism through the phosphorolytic cleavage of cellodextrin mixture produced as cellulosic degradation products.

The finite amount of energy carriers affects all of us. It is important to utilize all available sources and to find new sources of energy. The confectionery industry generates both solid and liquid waste during the production of confectioneries, which could be utilized as a substrate for biogas production. However, problems might arise during the biogas process since these kinds of waste are very rich in carbohydrates. The initial breakdown of the substrate would probably cause an accumulation of fermentation products such as volatile fatty acids (VFA) and a low pH. A solution to this might be to use a two-stage process. The first stage would be a pre-fermentation that should be optimized for production of fermentation products such as ethanol and VFA. The aim of this master thesis is to evaluate the biogas potential of confectionery waste products. The confectionery waste products are evaluated using a continuous two-stage process, batch experiments and theoretical calculations of the methane potential. The potential from process wastewater was examined. Depending on COD reduction for a reactor and COD content of process wastewater, an annual amount of 75 000 m3 or of 857 000 m3 of process wastewater is necessary to produce enough biogas for a gas engine to continuously convert the biogas to electricity. A batch experiment evaluating the methane production potential of nine different confectionery waste products from a large confectionery industry gave a range of 430 - 690 NmL/g VS, which is relatively high. A continuous experiment in two lab-scale reactors with a HRT of two days worked satisfactory. The gas production was stable periodically with a carbon dioxide content above 60%. The pH was low (3.4 - 3.6) throughout the experiment for one of the reactors. However, addition of digester sludge from a methane-producing reactor towards the end of the experiment resulted in a higher pH and more VFA available for utilization in the second stage. The main fermentation products were: acetic acid, lactic acid, ethanol and carbon dioxide. A second batch experiment showed that the methane potential was not affected by pre-fermentation. A carbon balance calculation of the process indicates that 57% of the ingoing organic matter is fermented within only two days and ends up in the known fermentation products. The study shows that confectionery waste products are well suited for two-stage anaerobic digestion. / Den ändliga mängden av energibärare påverkar oss alla. Det är därför viktigt att utnyttja alla tillgängliga men även att finna nya energibärare. Konfektyrindustrin generar restprodukter (avfall) både i fast och flytande form, vilka båda kan utnyttjas för produktion av biogas. Det kan dock uppstå problem i biogasprocessen eftersom dessa innehåller en stor mängd kolhydrater. Den initiala nedbrytningen kan ge upphov till en ackumulering av VFA och ett lågt pH. En lösning på detta problem kan vara att använda en två-stegs process. Första steget är en för-fermentering, som ska optimeras för att producera fermentationsprodukter så som etanol och VFA. Syftet med detta arbete är att utvärdera biogaspotentialen från konfektyrrestprodukter genom att använda en kontinuerlig två-stegs process, batchförsök och teoretiska beräkningar av metanpotentialen. Potentialen undersöktes från processvatten. Beroende på COD reduktion i en reaktor och COD innehåll i processvatten, är en årlig mängd av 75 000 m3 eller av 857 000 m3 processvatten nödvändig för att producera en tillräcklig mängd biogas så att en gasmotor kontinuerligt kan omvandla biogasen till elektricitet. Ett batchförsök med nio olika restprodukter från en storskalig konfektyrproducent visade en relativt hög metanpotential (430 - 690 NmL/g VS). Ett kontinuerligt reaktorexperiment genomfördes i laboratorieskala med två reaktorer, där uppehållstiden var två dagar. De två för-fermenteringsreaktorerna presterade tillfredsställande. Gasproduktionen var periodvis stabil med en koldioxidhalt över 60%. pH var lågt (3,4 och 3,6) genom hela experimentet för en av reaktorerna. För den andra reaktorn gjordes tillsatser av reaktormaterial från en metanproducerande reaktor i slutet av experimentet. Dessa tillsatser ökade pH och totalmängden av VFA, som kan utnyttjas i det andra steget. Huvudfermentationsprodukterna är acetat, laktat, etanol och koldioxid. Ytterligare batchförsök visade att för-fermentation inte verkar påverka metanpotentialen för konfektyrrestprodukter. En kolbalans av processen indikerar att 57% av ingående kol återfinns i de kända fermentationsprodukterna inom två dagar. Studiens resultat visar att avfallsprodukter från konfektyrindustrin lämpar sig väl för två-stegs anaerob rötning.

Tez (Yüksek Lisans) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Yapı Eğitimi Anabilim Dalı, 2008. / Kaynakça var.

Two coal utility plants in South Africa selected (one from Sasol and another from Eskom) for this study produce large volumes of fly ash (over 40 Mt from Eskom at Tutuka, and 3 Mt from Sasol Synfuels at Secunda annually), and brines as by-products during coal processing. Co-disposal of the brines and fly ashes has been a normal practice in these coal-utility plants for decades. Long-term management of fly ash is necessary and requires an understanding and knowledge of how the different waste materials interact with water and brines in different chemical situations. However the geochemistry of their interactions, the leaching and mobility of elements in these disposal systems has not been fully understood. This work gives insights into the chemical processes taking place in the brine-water/brines systems that govern the concentrations of major and minor elements in ash leachates under different environmental conditions. The possible presence of organic compounds (subsequently referred to as 'organics') in brines and their effects on the leaching chemistry of fly ash was also studied. Sustainability and long term impact of the co-disposal of fly ash and brines on the environment was studied through static (batch tests) modeling of the pH-dependent acid neutralization capacity (ANC) tests and columns modeling for dynamic leach tests. The modeling was based on experimental results from other Sasol-Eskom ashbrine project collaborators. Modeling results of the ANC tests were in good agreement with the reported experimental results, which revealed that the release trends of various elements (including trace, heavy elements and contaminants) contained in fly ash into solution is highly pH dependent. However Na, K, Mo and Li exhibited constant solubilisation which was independent of pH changes from all the scenarios. The presence of different constituents of brines subjected to ANC resulted to different ANC capacities ranging from 0.98 moles H⁺/Kg dry ash (of ash-organics mixed with Mg-brines) to 3.87 H⁺/Kg dry ash for those with the C(4) brines. As expected, those constituents from the cationic brines were found on the lower region of acid addition (in the order Mg-brines < Ca-brines < Na-brines) while the anionic brines were found at the upper region of acid addition (in the order S(6)-brines < Cl-brines < C(4)-brines). In the middle region of acid addition were three important scenarios: that of ash with brine, ash without brines (i.e. ash with DMW) and ash with both ASW organics and combined brines. It was from these three scenarios that a generalization of the effect of brines and organics on the ANC was inferred. The ANC of ash with demineralised water (DMW) was 2.33 mol H⁺/Kg dry ash and that of ash with ASW organics lower at 2.12 mol H⁺/Kg dry ash which was the same value as that of ash with combined brines. This indicated that brines decreased the ANC of ash by about 9.01 % and which could be attributed to the acid-base neutralization process and the dynamics of solid phase dissolutions in response to the acid addition. Both fly ashes exhibited a typical pH > 12 (suspension in demineralised water) and the predominant cation even at this high pH is Ca²⁺ (at concentration > 0.002 mmol/L). This indicates that dissolution of CaO and formation of OH⁻ species at pH > 10 contributes to acid neutralisation capacity of both fly ashes and is the greatest contributor to the acid neutralizing capacity of both fly ashes. Two broad leaching behaviours as a function of pH were observed from the three fly ash-ASW organics-brines scenarios (i) leaching of Ca, Mg, Ni and Sr follows a cationic pattern where the concentration decreases monotonically as pH increases; (ii) leaching of Al, Fe, Ti and Zn follow an amphoteric pattern where the concentration increases at acidic and alkaline pH, although Al showed some anomaly from pH 11 where the concentration decreased with the increase in pH. Al showed an amphoteric pattern in which its release increased between pH 12.8 and 11 for all the scenarios and then decreased with decrease in pH down to neutral pH of 7. The batch leaching simulation results from hydrogeochemical modeling also showed that mineral dissolution, precipitation and new phase formation during ash-organics-brines interactions was controlled by pH. The newly formed phases however remain in equilibrium with the ash-brines-organics mixture. Each individual mineral phase dissolution/precipitation/formation system controls the concentration and speciation of the respective constituent elements as evidenced by the log C-pH diagrams obtained from the modeled scenarios. The ash-brines-organics interactions do exhibit and affect the mineralogical chemistry of fly ash. However the extent to which these interactions occur and their effect, varies from one scenario to another, and are dependent on the amounts and type of the constituent brine components. Organics do have a significant effect on dissolution characteristics of few minerals such as calcite, mullite, kaolinite, Ni₂SiO₄, and SrSiO₃ due to complexation effect. The effect is quantitatively conspicuous for calcite mineral phase and for the formation of some new phases such as Fe(OH)₃(am)-CF and portlandite. The composition of the liquid phase from acid neutralisation capacity experiments was successful.Hydrogeochemical modeling was used as a means to provide insights and understanding of the complex reactions taking place, speciation and mineralogical changes occurring. These changes would serve to predict future environmental scenarios when pH conditions change. In this study, an extension of the application field of PHREEQC hydrogeochemical code for modeling and simulation of equilibrium; kinetic and transport mechanisms associated with the interaction of water; and organics and brines with fly ash during their co-disposal is successfully demonstrated. The parameters associated with these mechanisms were used as inputs into the PHREEQC program using modified Lawrence Livermore National Laboratory (LLNL) database for inorganic brines and MINTEQ.V4 database for organics, and used to model the results of ANC test data for the fly ashes. A special reference is made to two separate modeled mineralogical ash recipes from two of the South African power utility plants' fly ash systems, namely, Tutuka and Secunda. The effects of brines in the leaching of major, minor and trace elements at various pH values and the mineralogical changes associated with the intermediate and final products from the interactions of ash-brines systems under different scenarios are qualitatively and quantatively discussed. Multiphase saturation characteristics have been determined for mineral species in contact with water and brines. The modeling results indicated that several mineral phases could be controlling the species concentration in the leachates, and the ANC and column modeling results corroborated well in many aspects with the experimental results obtained from collaborating institutions (South Africa Universities and Research institutions). In addition, application of the PHREEQC model to the ash heap under different disposal systems was carried out to predict the heap leachate composition and geochemical transformations taking place in a period of time. Pore water chemical analysis, and moisture content analysis revealed that contact of the ash with water is a crucial factor in the mobilization of the contaminants with time. Maximum weathering/dissolution of the ash is observed in the top layer (1-3) m and at the point of contact with the subsurface water level which was in good agreement with the model results. The surface layer and the very lowest layers of the dump in contact with lateral flows experience the highest degree of weathering leading to depletion of species. The geophysical transformation of fly ash was also captured through the porosity change calculations and the results revealed that geochemical reactions do affect the porosity of fly ash during the weathering processes. These modelling results were in agreement with the hydraulic tests and salt leaching tests conducted during Sasol-Eskom ashbrine project in Phase I which suggested that salts captured in the ash will become mobile and leach from the fly ash over time. The data therefore indicates that ash dumps may not act as sustainable salt sinks. These findings may have some bearing on engineering decisions on fly ash reuse. From the above observations, it is apparent that release of large quantities of the salts in the ash depends on the extent of its interaction with brines being used for irrigation or with water, either through plug-in flow after a rainfall event or contact with groundwater. The results revealed effects of brine-water contact time with fly ash, the flow volume and velocity, the pH, the degree of saturation, hydrogeology and ash heap geometry as important factors that affect fly ash transformation and weathering. Overall, the ash heap modeling enhanced the understanding of the ash-brines interactions and demonstrated that leachate composition is determined by the following factors; (i) the mass flows from the pores of fly ash, (ii) the surface dissolution of the mineral phases, (iii) the various chemical reactions involved during the ash-brine and ash-water interactions, (iv) the interactions with a gas phase (atmospheric CO₂), (v) the composition of the initial fly ash, and (vi) by the leachate flow and hydrodynamics as captured in the conceptual model. Any ash handling system should therefore be designed to take these criteria into consideration to prevent environmental contamination. The modeling results also gave indications that the ash-brine co-disposal in dry ash systems would be an unsustainable way of locking up brine salts in the long run. In this Thesis, modeling results were used to support experimental data which further reaffirmed the important role hydrogeochemical modeling plays in liquid and solid waste management. Furthermore, hydrogeochemical modeling complements the work of analytical/environmental scientists as well as guiding the future solid waste management and engineering decisions. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2012.

Every time a good is produced, waste occurs as an unwanted by-product. Waste has become a real environmental issue across the world, contributing to the degradation of the environment and human health. As part of a local and international effort to lessen industrial pollution, a concept to reduce waste production at source was introduced to companies in the early 1990s. Pioneered in the Netherlands and the United Kingdom (UK), this concept has been termed 'waste minimisation'. Waste minimisation is achieved by implementing changes to business practices and processes, such as improved housekeeping (e.g. prevention of spills), and changes to equipment that is less wasteful. It is often undertaken by a group of organisations, including for example service providers, manufacturing companies and regulators that join a waste minimisation club (WMC). This provides an opportunity in which training can be received by, waste minimisation assessments made on, and information and ideas about waste reduction at source exchanged by member companies. WMCs have been used successfully in Europe to achieve waste minimisation in industry and residential communities. This study aims to contribute to the development of a sustainable WMC model in South Africa. It analyses the WMC support structures in South Africa and compares them to support structures offered in the UK. This offers a point of reference from which the impact of South African support structures on WMCs in general, and the Pietermaritzburg Waste Minimisation Club (PWMC) in particular, can be established. The PWMC consists of small and medium companies across sectors, each with less than 200 employees and with an annual turnover less than 40 million rand. The club was initiated by the Pollution Research Group of the University of KwaZulu-Natal (UKZN). It was the first of its kind in South Africa, having been facilitated on a small budget by staff and students from the UKZN. The study found that the self-help approach adopted by the PWMC was only partially successful. The PWMC was successful in terms of raising awareness of its members to waste minimisation issues. The study also found that member companies, both from the PWMC and WMCs generally, need to be shown in practical terms that 2 waste minimisation can result in financial savings before management buy-in can be attained. If more University manpower had been allocated, in the form of students for instance, to identify and orchestrate implementation of sustainable waste minimisation solutions, the PWMC member adoption rate of waste minimisation may have been raised. The small PWMC budget may have made this impossible, however. Lack of funding may also have prevented facilitators putting together a large support team, as has been done for a similar and more successful project in England. This demonstrates that self-help WMCs need an initial funding boost to be successful. This funding should be invested in gaining buy-in from company personnel rather than to drive the waste minimisation process on behalf of member companies. Driving waste minimisation on behalf of companies or 'hand-holding' leads to a passive acceptance of waste minimisation as is currently the case in South Africa, as well as 'shirking' as has been observed in the UK. Such a facilitated self-help approach can then lay the basis for WMCs, which use the support infrastructure established by their predecessors. Studies of WMCs in England and Wales based on a self-help approach showed that they achieved financial savings that are comparable to those in demonstration clubs. The promotion of such sustainable WMCs in South Africa needs to be performed by a central support agency such as the British Envirowise. Envirowise was seen to successfully promote waste minimisation among those it reached. However, it reached only a small percentage of overall industry. A successful South African agency therefore needs to promote itself effectively and nation-wide. A successful South African Envirowise organisation should also facilitate the creation of WMCs by leading a forum of industry, service providers, higher education and waste minimisation champions of proven worth, to create an action plan for WMC development for each province. Each province would then allocate funds for a waste minimisation champion who, in conjunction with the local development agency, would create a provincial action plan for the development of facilitated self-help WMCs. The local support and expertise recruited to form and manage WMCs would decrease costs and leverage income. This kind of support agency needs to be upheld by waste management legislation based on the concept of sustainable development, recognising the need for environmental protection alongside that of economic growth. To date no such legislation is in place in South Africa. It is hoped that the White Paper on Integrated Pollution and Waste Management, which endorses the principle of sustainable development alongside with the necessity to reduce waste at source, will form the basis for a successful South African WMC culture. / Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.