Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains viii, 65 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 54-57).

Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 115-119). Also available in electronic format on the Internet.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-07-27T13:12:58Z No. of bitstreams: 1 NAIARA ÂNGELO GOMES - DISSERTAÇÃO (PPGECA) 2017.pdf: 2054177 bytes, checksum: b38a4c9f046028dc334d619defff13e3 (MD5) / Made available in DSpace on 2018-07-27T13:12:58Z (GMT). No. of bitstreams: 1 NAIARA ÂNGELO GOMES - DISSERTAÇÃO (PPGECA) 2017.pdf: 2054177 bytes, checksum: b38a4c9f046028dc334d619defff13e3 (MD5) Previous issue date: 2017-03-03 / Capes / O aterro sanitário é a técnica de disposição final de resíduos sólidos urbanos mais utilizada no mundo. No entanto, devido à complexidade do processo de degradação biológica que ocorre no interior das células de resíduos, são gerados os líquidos lixiviados, que em função de serem efluentes tóxicos, heterogêneos e com uma composição bastante variada e complexa, podem causar toxicidade à saúde pública e ao meio ambiente. Assim, o objetivo deste trabalho foi analisar o potencial tóxico do lixiviado gerado em uma célula do Aterro Sanitário localizado em Campina Grande, Paraíba. O experimento consistiu em coletar quinzenalmente, durante os meses de junho a novembro do ano de 2016, amostras de lixiviado in natura em um poço de visita que recebia todo o líquido efluente gerado pela célula estudada. Após as coletas, o lixiviado foi caracterizado por meio de ensaios físico-químicos (pH, alcalinidade total, ácidos graxos voláteis, cloretos, demanda química de oxigênio, nitrogênio amoniacal total e metais pesados) e toxicológico (fitotoxicidade). Além disso, fez-se ainda, uma análise estatística dos dados obtidos durante o período de monitoramento. Os resultados demonstraram que em condições ácidas de pH, o lixiviado apresentou elevadas concentrações de ácidos graxos voláteis, demanda química de oxigênio e metais, em especial, ferro, manganês e cromo, os quais foram os principais elementos a ocasionarem fitotoxicidade às sementes de tomate (Solanum lycopersicum) e de repolho (Brassica oleraceae). Contudo, quando o pH do lixiviado tendeu para valores entre a neutralidade e a basicidade, as concentrações dos metais analisados tiveram um decaimento, reduzindo, dessa forma, o potencial de toxicidade do lixiviado em relação aos metais. Porém, durante esse período, foram determinados os maiores teores de nitrogênio amoniacal total, mas, devido ter prevalecido no lixiviado o nitrogênio na forma de íon amônio, esse componente, provavelmente, não conferiu toxicidade as referidas sementes. Conclui-se que, o lixiviado apresentou um maior potencial fitotóxico na fase de degradação ácida, e, com a evolução do processo de biodegradação dos resíduos depositados na célula analisada, os ensaios de fitotoxicidade evidenciaram um lixiviado com uma menor carga tóxica. / Sanitary landfilling is the most widely used final disposal technique for municipal solid waste in the world. However, due to the complexity of the biological degradation process inside the waste mass, the leachate liquid are generated. The leachate requires special attention, because it is a toxic, heterogeneous effluent with a very varied and complex composition; can cause promote toxicity to health public and the environment. In this context, this work aimed to analyze the toxic potential of leachate generated in a landfill cell in Campina Grande – State of Paraiba, Brazil. The experiment consisted of collecting samples of fresh leachate (biweekly from June to November of 2016) in a well that received all the liquid generated by the landfill cell studied, from the landfill of Campina Grande. After collection, the leachate was characterized by physical-chemical (pH, total alkalinity, volatile fatty acids, chlorides, chemical oxygen demand, total ammonia nitrogen and heavy metals) and toxicological (phytotoxicity) analyses. In addition, the correlations between these parameters were verified. The results registered that in acidic conditions of pH, the leachate presented high concentrations of volatile fatty acids, biochemical demand of oxygen and metals (especially iron, manganese and chromium). These were the main factors causing phytotoxicity of tomato (Solanum lycopersicum) and cabbage (Brassica oleraceae) seeds. However, when the pH of the leachate tended to be between neutral and basic, the concentrations of the analyzed metals decreased, reducing the toxicity potential of the leachate in relation to the metals. Even so, during this period, the highest levels of total ammoniacal nitrogen were obtained. Because nitrogen in the form of ammonium ion prevailed in the leachate, this component probably did not infer toxicity to plant seeds. It can be concluded that the leachate presents a higher phytotoxic potential in the acid degradation phase. With the evolution of the biodegradation process of the residues deposited in cell studied, despite the high levels of ammoniacal nitrogen measured, the phytotoxicity tests evidenced a leachate with a lower toxic load.

Geossintéticos são materiais cada vez mais aplicados em aterros sanitários, cumprindo diferentes funções como barreiras para líquidos e gases. Na função de filtração, o uso destes materiais não está consagrado, principalmente, em função da possível colmatação total ou parcial dos geotêxteis por ação de microrganismos, a chamada colmatação biológica. Neste contexto, o presente trabalho visa avaliar a colmatação de geotêxteis tecidos e não tecidos submetidos ao fluxo de lixiviado de aterro sanitário. Foram utilizados três geotêxteis não tecidos de gramatura 200 g/m², sendo um de filamento contínuo de poliéster (PET) e dois de fibra curta, porém fabricados com polímeros diferentes poliéster e polipropileno (PET e PP) e um geotêxtil tecido de polipropileno, com gramatura 400 g/m². Para avaliar a colmatação dos geotêxteis montaram-se ensaios de permeabilidade de longa duração em que se mediu a condutividade hidráulica ao longo do tempo. Após os ensaios de permeabilidade, realizou-se microscopia eletrônica de varredura para avaliar o fechamento dos poros dos geotêxteis, além de avaliar o crescimento bacteriano ocorrido no interior do geotêxtil. Os resultados obtidos permitem constatar significativa redução da condutividade hidráulica dos materiais após o período de 30 dias de ensaios, onde notou-se a predominância do processo de cegamento. / Geosynthetics materials have been intensively used in landfills in different functions as liquid and gas barriers. As filters, geosynthetics are not completely accepted in designs, since total or partial geotextile clogging can occur for biotic deposition (or impregnation), usually named biological clogging. This work evaluates the clogging on nonwoven and woven geotextiles under leachate flow for landfill application. For this purpose, nonwoven geotextiles with short and long polyester filaments and mass per unit area of 200 g/m² were used, as well as polypropylene and polyester nonwoven geotextiles with mass per unit area of 400 g/m². Cross-plane permeability tests were periodically conducted in geotextiles samples which were under long term leachate flow. After each permeability test, scanning electron microscopy (SEM) was conducted to evaluate the source of pore geotextile clogging, as well as the bacteria growing into the geotextile matrix. Results have shown a significantly reduction on hydraulic conductivity of geotextile filters after 30 days of leachate flow, which was motivated by blinding process.

Orientador: José Roberto Guimarães, Adriano Luiz Tonetti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-20T11:06:57Z (GMT). No. of bitstreams: 1 Camargo_CristalCoserde_M.pdf: 3232845 bytes, checksum: 4af0902c3dd508db1427e0493892de25 (MD5) Previous issue date: 2012 / Resumo: O nitrogênio na forma amoniacal e encontrado em altas concentrações nos lixiviados de aterros sanitários e sua redução e imperativa quando se cogita o descarte do lixiviado em corpos de água. No presente trabalho objetivou-se a remoção de nitrogênio amoniacal no lixiviado do aterro Delta A, localizado na cidade de Campinas, São Paulo, por precipitação química e formação de fosfato de amônio e magnésio...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: When it comes to landfill leachates, ammonia is found in high concentrations and its reduction is imperative for adequate disposal. The present work studied the ammonia removal from the leachate of the landfill Delta A, located at the city of Campinas, Sao Paulo, through chemical precipitation and formation of magnesium ammonium phosphate...Note: The complete abstract is available with the full electronic document / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

The application of struvite (magnesium ammonium phosphate,!MgNH&PO& ∙ 6H+O) precipitation and its recycling use for the purpose of ammonia removal from both synthetic solutions and landfill leachate were investigated in this study. The results demonstrated that chemical precipitation by struvite formation is efficient for ammonia removal from aqueous solutions. In addition, by recycling the thermal residue of struvite, continuously removing ammonia can technically be achieved. In the struvite precipitation, ammonia removal significantly depended on the pH and chemical molar ratios of NH& ,:!Mg+,:!PO& ./. For synthetic solution (TAN=1,000 mg/L), remarkable TAN removal efficiency of over 98% has been reported when the molar ratio of NH& ,:!Mg+,:!PO& ./ equals 1.0:1.2:1.2, 1.0:1.3:1.3, 1.0:1.3:1.4 and 1.0:1.5:1.5 at optimum pH 9. The optimum combinations of reagents applied in landfill leachate (TAN=1,878 mg/L) were!NH& ,:!Mg+,:!PO& ./ =1.0:1.3:1.3, 1.0:1.4:1.3, 1.0:1.5:1.4 and 1.0:1.5:1.5 at optimum pH 9.5, all of which displayed excellent TAN removal efficiencies of over 99%. Response surface method (RSM) helped to analyze the data and optimize the results. The struvite pyrolysate provided best performance of removing ammonia in both simulated wastewater and landfill leachate at a dosage of 60 g/L, when struvite was previously heated at 105 􀀁 by oven for 2.5 h. In the recycling phase, the struvite pyrolysate resulting from NaOH-mediated pyrolysis was more effective at continuously treating ammonia synthetic solution than was direct heating, with an initial mode of 87.4% at the beginning to 75.1% in the fifth round and direct heating of struvite from 80.9% in the first cycle and 60.6% in the final cycle. The struvite pyrolysate formed by NaOH-mediated pyrolysis performed with greater ability to continuously eliminate ammonia from landfill leachate (97.2% removal at the beginning and 72.3% in the fifth round), than did directly heated struvite (98.4% in the first cycle and 81.3% in the final cycle). Additionally, microwave irradiation could also dissociate struvite, which subsequently demonstrated moderate TAN removal in recycling phases.

No description available.

Potato (Solanum tuberosum L.) is one of the most important tuber crops globally and is classified amongst the most crucial food crops in Africa. South Africa has a very vibrant potato industry, producing about 2.5 million tonnes every year, with quantities bettered only by Algeria and Egypt. Potato production is very expensive (R150 000 ha-1), with fertilizers contributing 20%. Potato is highly reliant on steady nutrient supply and any deficiencies result in poor yield. Potato fertilizer demand is higher than that of other crops such as cereals and it has a very unique demand for phosphorus (P), which is vital from its early development to maturity. In addition, potato has a very shallow root system, which compromises P uptake, making most potato cultivars ineffective in nutrient uptake. Therefore, high P fertilizer rates are applied of which <20% is utilized by plants within a few days after application and about a further 4% within the next 10 days, mostly due to fixation. The production of P fertilizer, such as super phosphate (SP) is energy-consuming, costly and emits fluorine. There is also a risk of cadmium (Cd) accumulation in soils and plants due to the heavy fertilisation, posing a risk to human health, animals and aquatic life. Runoff phosphorus leads to eutrophication of water bodies. In addition, P fertilizer production is severely threatened by declining rock phosphate (RP) reserves, expected to hit a low by 2200. This will result in a hike in P fertiliser prices as miners move to low concentration ores. The high demand of P in potato, the environmental and human health risks, the high costs and declining reserves, all call for prudent and sustainable management of P in potato production. Nitrate and ammonium results in contrasting plant metabolism and growth. Most importantly through rhizosphere modification where ammonium supply results in reduced soil pH while nitrate results in increased soil pH. The pH reduction in ammonium supplied soils increases P dissolution and availability while the opposite is noted in nitrate. Most of the studies in this phosphorus-nitrogen interaction have been conducted on tree species, grasses and cereal crops with little done on tuber crops. In addition, the application of RP directly to plants could help cut the emissions, processing costs and environmental contamination associated with chemical P fertiliser production. There is, therefore, an urgent need to develop P fertilizer management systems to effectively manage this finite resource by improving its use efficiency for maximum yield at optimum application rates. To attain this objective, two experiments were conducted, namely a laboratory study to investigate the interaction between nitrogen forms and phosphorus sources in soil columns without a test crop, and a glasshouse pot trial to investigate the same interaction with potato as test crop. The column study treatments comprised of two soil types, N supplied as ammonium or nitrate and three P sources (SP, RP and a P0) to give 12 treatments that were replicated four times to give 48 columns. Mechanical dry packing method was used. The columns were leached with one pore volume over four watering events (1, 21, 42 and 63 days) and terminated on day 90. The leachate was collected in glass bottles at the column bases and analysed for pH, phosphorus, calcium, potassium and magnesium contents. A glasshouse pot trial was set up at the University of Pretoria Experimental Farm with potato cultivar Mondial as the test crop over two seasons, with a high and low initial soil P in season one and two, respectively. One minituber was planted per 10 litre pot. Watering was done using a pressure compensated drip irrigation system. Data was collected at tuber initiation (TI) and at the end of the season (ES). Parameters assessed included plant height, dry masses, number of tubers initiated, yield, leaf tissue and soil P status. Significant phosphorus-nitrogen interactions occurred on most assessed parameters in both trials. The exceptions were pH, potassium, phosphorus, calcium and magnesium levels, at some stages of the column study. Significant phosphorus-nitrogen interactions were noted at all watering events for both soil and leachate pH, phosphorus, potassium, calcium and magnesium concentration. In the pot trial, significant phosphorus-nitrogen interactions were noted for most of the plant measurements at both the TI and ES assessment periods with a few exceptions. Ammonium + SP produced the highest tuber initiation rate and final yield, as well as highest tissue and plant available P levels in both seasons. In the leachate and soils at the end of the column study, as well as at both stages assessed in the pot trial, ammonium treatments tended to have higher P contents. In the pot trial, ammonium treatments gave taller plants, but with lower dry mass compared to nitrate. Nitrate treatments had higher soil and leachate pH compared to ammonium treatments in both trials. Plants supplied with SP tended to have longer haulms and roots, higher haulm and root biomass and higher yield compared to treatments with RP and P0. The findings of these trials indicated that ammonium results in higher phosphorus dissolution (with or without a crop) and uptake by plants due to increased soil acidity. The resulting effect on potato crop is an increase in the number of tubers initiated and higher yields. However, the positive effect of ammonium was mostly achieved in combination with superphosphate. Rock phosphate, despite the increased yields, compared to treatments without P, gave inferior plant performance and is therefore not a worthy substitute for superphosphate. / Dissertation (MSc (Agric))--University of Pretoria, 2020. / Plant Production and Soil Science / MSc (Agric) / Unrestricted

The research presented in this paper evaluates the potential impact of municipal solid waste (MSW) landfill leachate quality on the loss of metals from discarded treated wood during disposal. The loss of arsenic (As), chromium (Cr), copper (Cu), and boron (B) from several types of pressure-treated wood (CCA: chromated copper arsenate, ACQ: alkaline copper quaternary, CBA: copper boron azole, and DOT: disodium octaborate tetrahydrate) using leachate collected from 26 MSW landfills in Florida was examined. The toxicity characteristic leaching procedure (TCLP), the synthetic precipitation leaching procedure (SPLP), and California's waste extraction test (WET) were also performed. The results suggested that loss of preservative components was influenced by leachate chemistry. Copper loss from CCA-, ACQ- and CBA-treated wood was similar in magnitude when in contact with landfill leachates compared to synthetic TCLP and SPLP solutions. Ammonia was found as one of the major parameters influencing the leaching of Cu from treated wood when leached with MSW landfill leachates. The results suggest that disposal of ACQ- and CBA-treated wood in substantial quantity in MSW landfills may elevate the Cu concentration in the leachate; this could be of potential concern, especially for a bioreactor MSW landfill in which relatively higher ammonia concentrations in leachate have been reported in recent literature. For the As, Cr and B the concentrations observed with the landfill leachate as the leaching solutions were over a range from some sample showing the concentrations below and some showing above the observed value from corresponding SPLP and TCLP tests. In general the WET test showed the highest concentrations.

abstract: Zero-Valent Metals (ZVM) are highly reactive materials and have been proved to be effective in contaminant reduction in soils and groundwater remediation. In fact, zero-Valent Iron (ZVI) has proven to be very effective in removing, particularly chlorinated organics, heavy metals, and odorous sulfides. Addition of ZVI has also been proved in enhancing the methane gas generation in anaerobic digestion of activated sludge. However, no studies have been conducted regarding the effect of ZVM stimulation to Municipal Solid Waste (MSW) degradation. Therefore, a collaborative study was developed to manipulate microbial activity in the landfill bioreactors to favor methane production by adding ZVMs. This study focuses on evaluating the effects of added ZVM on the leachate generated from replicated lab scale landfill bioreactors. The specific objective was to investigate the effects of ZVMs addition on the organic and inorganic pollutants in leachate. The hypothesis here evaluated was that adding ZVM including ZVI and Zero Valent Manganese (ZVMn) will enhance the removal rates of the organic pollutants present in the leachate, likely by a putative higher rate of microbial metabolism. Test with six (4.23 gallons) bioreactors assembled with MSW collected from the Salt River Landfill and Southwest Regional Landfill showed that under 5 grams /liter of ZVI and 0.625 grams/liter of ZVMn additions, no significant difference was observed in the pH and temperature data of the leachate generated from these reactors. The conductivity data suggested the steady rise across all reactors over the period of time. The removal efficiency of sCOD was highest (27.112 mg/lit/day) for the reactors added with ZVMn at the end of 150 days for bottom layer, however the removal rate was highest (16.955 mg/lit/day) for ZVI after the end of 150 days of the middle layer. Similar trends in the results was observed in TC analysis. HPLC study indicated the dominance of the concentration of heptanoate and isovalerate were leachate generated from the bottom layer across all reactors. Heptanoate continued to dominate in the ZVMn added leachate even after middle layer injection. IC analysis concluded the chloride was dominant in the leachate generated from all the reactors and there was a steady increase in the chloride content over the period of time. Along with chloride, fluoride, bromide, nitrate, nitrite, phosphate and sulfate were also detected in considerable concentrations. In the summary, the addition of the zero valent metals has proved to be efficient in removal of the organics present in the leachate. / Dissertation/Thesis / Masters Thesis Environmental and Resource Management 2019