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Bário, cádmio e cromo em latossolo e plantas de milho no décimo oitavo ano de aplicação de lodo de esgoto /Rocha, Antonio Márcio Souza January 2016 (has links)
Orientador: Wanderley Jose de Melo / Banca: Wilson José Oliveira de Souza / Banca: Renato de Mello Prado / Resumo: A presença de elementos traços no lodo de esgoto (LE) é uma das restrições quanto ao seu uso em áreas agrícolas. Nesse sentido, objetivou-se com este estudo avaliar os efeitos da aplicação do lodo, aos dezoito anos, em Latossolo Vermelho eutroférrico sobre a concentração pseudototal e disponível de Ba, Cd e Cr na profundidade de 0 - 0,2 m, bem como quantificar os mesmos metais na parte aérea de plantas de milho. O experimento foi desenvolvido em condições de campo, utilizando-se o delineamento experimental em blocos casualizados com 4 tratamentos e 5 repetições. Os tratamentos foram: 0 Mg ha-1 controle (sem lodo de esgoto e com fertilização mineral), 5; 10 e 20 Mg ha-1 de LE, base seca. Os teores pseudototais e disponíveis de Ba não foram influenciados pelas doses de LE, na profundidade de 0 - 0,2 m. A concentração média de Cd pseudototal foi aproximadamente 1,784 mg kg-1, enquanto que o teor Cr foi maior na dose de 20 Mg ha-1. Esta dose proporcionou, ainda, uma maior disponibilidade para Cd e Cr. Os teores de Ba, Cd e Cr na planta de milho não foram incrementados pelas doses de lodo de esgoto no décimo oitavo ano de aplicação. / Abstract: The presence of trace elements in sewage sludge (SS) is one of the restrictions on its use in agricultural areas. In this sense, the objective of this study was to evaluate the effects of application of sewage sludge supplemented with K, at eighteen, in Haplortox on pseudototal concentration and available Ba, Cd and Cr in the depth of 0.2 m, and to quantify the same metals in the whole plant corn. The experiment was conducted under field conditions, using the experimental randomized block design with 4 treatments and 5 repetitions. The treatments were: 0 Mg ha-1 = control (without sewage sludge and mineral fertilization), 5; 10:20 Mg ha-1 of sewage sludge, dry basis. The pseudototais and available levels of Ba were not affected by LE doses at a depth of 0.2 m. The average concentration was approximately 1,784 Cd pseudototal mg kg, while the Cr content was greater in the 20 mg h-1. This dose provided also a greater willingness to Cd and Cr. The Barium, Cd and Cr in corn plant were not incremented by sewage sludge doses in the eighteenth year of application. / Mestre
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Co-digestão anaeróbia de dejetos de bovinos e dois tipos de glicerina brutaBertozzo, Fernanda [UNESP] 17 December 2013 (has links) (PDF)
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000751281.pdf: 1417271 bytes, checksum: fa65857f4f8010ff39d07e4ccfef8730 (MD5) / A glicerina bruta é um resíduo da produção de biodiesel de baixo valor agregado, no entanto, possui alto teor de carbono e potencial para produzir bons resultados se co-digerida de maneira anaeróbia com um material rico em nitrogênio como os dejetos de animais. Sendo assim, objetivou-se com este trabalho avaliar a co-digestão de dejetos de bovinos leiteiros e dois tipos de glicerina bruta: bruta e bruta loira, em biodigestores anaeróbios operados em sistema semi-contínuo, sob delineamento experimental inteiramente casualizado com cinco repetições por tratamento, sendo DBL – dejetos de bovinos leiteiros + água; DBL+GB – dejetos de bovinos leiteiros + glicerina bruta + água; DBL+GL – dejetos de bovinos leiteiros + glicerina bruta loira + água. As cargas diárias foram iniciadas tanto no DBL+GB como no DBL+GL com 1,25% de glicerina bruta passando em seguida para 2,5; 5; 7,5, 10, 15 e 20%; os aumentos nas porcentagens foram graduais e realizados a cada 30 dias, sendo este o TRH estabelecido. Os parâmetros avaliados foram: pH, acidez volátil (AV), alcalinidade total (AT), relação AV/AT, temperatura, reduções dos teores de sólidos totais (ST) e de sólidos voláteis (SV), produção de biogás/dia, teor de metano (CH4), potencial de produção de biogás por quilograma: de substrato (m3 kg-1 subst.), de sólidos totais adicionados (m3 kg-1ST adic.), de sólidos voláteis adicionados (m3 kg-1 SV adic.) e de dejetos de bovinos leiteiros (m3 kg-1 dej.), teores de... / Crude glycerin is a waste from biodiesel production with a low added value, however, it has a high carbon content and potential to produce good results if it is co-digested with a rich nitrogen material as animal manures. This way, the aim of this study was the co-digestion evaluation of dairy cattle manures and two types of crude glycerin: crude and blonde crude, in anaerobic digesters operated in semi-continuous system, under experimental design entirely randomized with 5 repetitions for each treatment, DBL – dairy cattle manures + water; DBL+GB - dairy cattle manures + crude glycerin + water; DBL+GL - dairy cattle manures + blonde crude glycerin + water. Daily loads were initiated both in DBL+GB and DBL+GL with 1,25% of crude glycerin and then rising to 2,5; 5; 7,5, 10, 15 and 20%; increases in percentages were made gradually and every 30 days. The parameters assessed were: pH, volatile fatty acids (VFA), total alkalinity (TA), VFA/TA ratio, temperature, removal of total solids (TS) and volatile solids (VS), biogas production, methane rate (CH4), potential of biogas production per kilogram: of substrate (m3 kg-1 subst.), total solids added (m3 kg-1 TS add.), volatile solids added (m3 kg-1 VS add.) and dairy cattle manures (m3 kg-1 dej.), nitrogen, phosphorus, potassium, carbon and organic matter content and carbon/nitrogen ratio. Least Square Means statistics was used to analyze the data (p<0,05). DBL+GB and DBL+GL treatments provided increments in biogas production in relation to DBL in all crude glycerin percentages tested. CH4 contents have been satisfactory and always above 59%, in all treatments. The ST and VS removals from DBL were less than DBL+GB and DBL+GL, and in these, increases in crude glycerin quantities accompanied. Potentials of biogas production varied according to the analyzed parameter: per kg of substrate and per kg of manures were higher in DBL+GB and in DBL+GL ...
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Análise da viabilidade da reciclagem de dejetos de bovinos com tratamento biológico, em sistema intensivo de produção de leiteCampos, Aloísio Torres de [UNESP] 26 August 1997 (has links) (PDF)
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campos_at_dr_botfca.pdf: 540232 bytes, checksum: a35a4cac7aab273cfb7389bf3d329beb (MD5) / O objetivo deste trabalho foi avaliar o desempenho econômico e a eficiência do tratamento biológico aeróbio, na redução e estabilização da matéria orgânica biodegradável, de dejetos líquidos de bovinos, visando a sua reciclagem na limpeza hidráulica das instalações dos animais (free stall) e sua posterior utilização nas áreas de produção de forragem. O trabalho foi desenvolvido nas instalações do Sistema Intensivo de Produção de Leite (SIPL) da Embrapa - Centro Nacional de Pesquisa de Gado de Leite (CNPGL), situado no município de Coronel Pacheco, MG. Dois reatores com capacidade útil de 300 m3 cada um foram construídos para compor as unidades do processo de lodo ativado por batelada (LAB), com sistemas de aeração prolongada e intermitente. Esses reatores foram dimensionados para um tempo de detenção hidráulico de 24 dias, com diluição dos dejetos (fezes + urina) em água na proporção de 1:1. Em cada reator foi instalado um aerador-misturador submersível, regulados para períodos de aeração de nove minutos e não-aeração de 18 minutos. Uma motobomba de rotor aberto, com vazão de 60 m3/h, foi utilizada para reciclar o efluente tratado sobre os corredores dos galpões de confinamento free stall e promover a limpeza hidráulica dos dejetos, que retornam aos tanques de aeração por gravidade por meio de canaletas. A drenagem dos reatores foi processada por uma motobomba submersa, com vazão de 10 m3/h, conduzindo o efluente até as áreas de produção de forragem, por escoamento superficial. A caracterização dos efluentes foi realizada por meio de amostragens na entrada e no interior dos tanques de aeração, na saída da tubulação de irrigação e dos dejetos puros dos animais. Foram analisados os seguintes parâmetros: pH, temperatura, óleos e graxas, DBO total e solúvel, DQO total e solúvel, sólidos totais fixos e voláteis sólidos... / The objective of this work was to evaluate the economic performance and efficiency of an aerobic biological treatment on the reduction and stabilization of the biodegradable organic matter of the bovine liquid manure. This effluent will be recycled in the hydraulic cleaning of the facilities (free stalls) and utilized in grass production areas. This work was done in the Embrapa - milk production intensive system (MPIS) facilities in Coronel Pacheco, state of Minas Gerais. Two reactors with capacity of 300 m3 each were built as the activated sludge sequencing batch reactor (SBR) units with prolonged and intermittent aeration. These reactors were dimensioned for a hydraulic retention time of 24 days with wastewater (manure + urine) dilution in water on the proportion of 1:1. In each reactor a submerged aerator-mixer was installed, with aeration and non-aeration periods of 9 and 18 minutes, respectively. A motor-pumping equipment with open rotor and flow of 60 m3/h was used for recycling the treated effluent on the halls of the free stall confinement facilities and to promote hydraulic cleaning of the effluent that will return to the aeration tanks by gravity conducted by channel structures. The drainage of the reactors was processed by a submerged motor-pumping equipment with flow of 10 m3/h driving the effluent to the grass production areas throughout superficial disposal. Effluent characterization was done by collecting samples on the entrance and the interior of the tanks, on the gate of the irrigation tubulation and on the bovine pure manure. There were analyzed the following parameters: pH, temperature, oils and fats, soluble and total BOD, soluble and total COD, volatile and total solids, sedimented solids, ammonia and total nitrogen, potassium, total phosphorus, magnesium and sodium. To evaluate the economic performance of the system, the costs, the annual investments... (Complete abstract click electronic access below)
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Potencial de minimização do material biodegradavel de alimentação contido no residuo solido domiciliar em municipios da Região Metropolitana de Campinas / Minimization potencial of food biodegradable material contained in the domiciliary solid waste in cities of the metropolitan region of CampinasNagle, Elizabeth Camargo 17 December 2004 (has links)
Orientador: Egle Novaes Teixeira / Dissertação (mestrado) - Universidade Estadual de Campinas. Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-04T04:06:18Z (GMT). No. of bitstreams: 1
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Previous issue date: 2004 / Resumo: Com o crescimento urbano e a mudança dos padrões de consumo, houve o aumento da quantidade e qualidade do material descartado. Desta forma, com a produção de material cada vez mais complexo e a composição do resíduo sendo freqüentemente alterada, a estratégia de gestão e gerenciamento para solucionar o problema, fica mais difícil. A tendência mundial, em relação aos problemas provenientes do resíduo sólido, é a busca contínua de formas adequadas para dispô-lo e, com a consciência ambiental sendo fortemente incentivada, deve-se buscar minimizá-lo, como princípio. A realidade do futuro sustentável do ambiente traz como premissas, a redução, reutilização e reciclagem, ou seja, a Minimização de Resíduo. O objetivo deste trabalho foi avaliar o potencial de Minimização do Material Biodegradável de Alimentação contido no Resíduo Sólido Domiciliar de Municípios da Região Metropolitana de Campinas. Identificou-se o que estava presente no resíduo sólido domiciliar, através de caracterização (determinação da composição gravimétrica), adaptada para a minimização, que foi realizada durante o período de um ano, nos domicílios dos municípios de Valinhos, Vinhedo e na macrozona três do município de Campinas. Escolheu-se os bairros e trinta domicílios por município, considerando-se a classe social. Em cada dia pré estabelecido, coletou-se o resíduo diretamente nas casas, perfazendo um total de 480 amostras no período analisado. Após o tratamento dos dados, foi calculado o potencial de minimização do material biodegradável de alimentação, que apresentou valores acima de 50%, indicando que muito tem para ser feito. As possibilidades de minimização do resíduo foram avaliadas e para cada tipo de desperdício são apresentadas maneiras para viabilizá-lo. No âmbito de gerenciamento integrado de resíduo dos municípios, esta pesquisa fornece parâmetros científicos para embasar ações e mecanismos de planejamento que incentivem e conduzam a população ao desenvolvimento consciente, à melhor utilização dos produtos/ material, sem desperdício e levando em consideração a esgotabilidade do ambiente / Abstract: An increase of the amount and quality of the discarded material has arisen as a result of the urban growth and the change of consumption standards. With the production of material each day more complex and the composition of the waste being frequent1y modified, the treatment to this problem becomes more difficult. The worldwide trend, in relation to the problems associated with solid waste, is the continuous search for adequate forms for its disposal, and with the environment conscience being strongly stimulated; one must pursue means to minimize it, as a principle. The reality of the sustainable future of the environment brings as premises, the reduction, reutilization and recycling, or either, the Waste Minimization. The objective of this work was to evaluate the potential of Minimization of the Food Biodegradable Material contained in the Domiciliary Solid Waste in Cities of the Metropolitan Region of Campinas. It was identified what was present in the domiciliary solid waste, through the characterization, determination of the gravimetrical composition, that was carried through during the period of one year, in Valinhos, Vinhedo and in the macro zone three of Campinas, choosing the regions and the thirty domiciles, collecting the residue direct1y in these and considering its social standards. After the treatment of the data, the potential of the minimization of the biodegradable food material, which was found to be above 50%, was calculated and the possibilities of minimization were evaluated taking into account viable mechanisms to make it. Within the scope of the integrated municipal solid-waste management plan, the current research provides scientific parameters to support actions and mechanisms that stimulate and lead the population to the conscientious development, better use of the materials, without wastefulness and taking in consideration the environment exhaustion / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil
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Co-digestão anaeróbia de dejetos de bovinos e dois tipos de glicerina bruta /Bertozzo, Fernanda, 1981. January 2013 (has links)
Orientador: Jorge de Lucas Júnior / Banca: Monica Sarolli S. M.Costa / Banca: Adriane de Andrade Silva / Banca: Marco Antonio M. Biaggioni / Banca: Sérgio Campos / Resumo: A glicerina bruta é um resíduo da produção de biodiesel de baixo valor agregado, no entanto, possui alto teor de carbono e potencial para produzir bons resultados se co-digerida de maneira anaeróbia com um material rico em nitrogênio como os dejetos de animais. Sendo assim, objetivou-se com este trabalho avaliar a co-digestão de dejetos de bovinos leiteiros e dois tipos de glicerina bruta: bruta e bruta loira, em biodigestores anaeróbios operados em sistema semi-contínuo, sob delineamento experimental inteiramente casualizado com cinco repetições por tratamento, sendo DBL - dejetos de bovinos leiteiros + água; DBL+GB - dejetos de bovinos leiteiros + glicerina bruta + água; DBL+GL - dejetos de bovinos leiteiros + glicerina bruta loira + água. As cargas diárias foram iniciadas tanto no DBL+GB como no DBL+GL com 1,25% de glicerina bruta passando em seguida para 2,5; 5; 7,5, 10, 15 e 20%; os aumentos nas porcentagens foram graduais e realizados a cada 30 dias, sendo este o TRH estabelecido. Os parâmetros avaliados foram: pH, acidez volátil (AV), alcalinidade total (AT), relação AV/AT, temperatura, reduções dos teores de sólidos totais (ST) e de sólidos voláteis (SV), produção de biogás/dia, teor de metano (CH4), potencial de produção de biogás por quilograma: de substrato (m3 kg-1 subst.), de sólidos totais adicionados (m3 kg-1ST adic.), de sólidos voláteis adicionados (m3 kg-1 SV adic.) e de dejetos de bovinos leiteiros (m3 kg-1 dej.), teores de ... / Abstract: Crude glycerin is a waste from biodiesel production with a low added value, however, it has a high carbon content and potential to produce good results if it is co-digested with a rich nitrogen material as animal manures. This way, the aim of this study was the co-digestion evaluation of dairy cattle manures and two types of crude glycerin: crude and blonde crude, in anaerobic digesters operated in semi-continuous system, under experimental design entirely randomized with 5 repetitions for each treatment, DBL - dairy cattle manures + water; DBL+GB - dairy cattle manures + crude glycerin + water; DBL+GL - dairy cattle manures + blonde crude glycerin + water. Daily loads were initiated both in DBL+GB and DBL+GL with 1,25% of crude glycerin and then rising to 2,5; 5; 7,5, 10, 15 and 20%; increases in percentages were made gradually and every 30 days. The parameters assessed were: pH, volatile fatty acids (VFA), total alkalinity (TA), VFA/TA ratio, temperature, removal of total solids (TS) and volatile solids (VS), biogas production, methane rate (CH4), potential of biogas production per kilogram: of substrate (m3 kg-1 subst.), total solids added (m3 kg-1 TS add.), volatile solids added (m3 kg-1 VS add.) and dairy cattle manures (m3 kg-1 dej.), nitrogen, phosphorus, potassium, carbon and organic matter content and carbon/nitrogen ratio. Least Square Means statistics was used to analyze the data (p<0,05). DBL+GB and DBL+GL treatments provided increments in biogas production in relation to DBL in all crude glycerin percentages tested. CH4 contents have been satisfactory and always above 59%, in all treatments. The ST and VS removals from DBL were less than DBL+GB and DBL+GL, and in these, increases in crude glycerin quantities accompanied. Potentials of biogas production varied according to the analyzed parameter: per kg of substrate and per kg of manures were higher in DBL+GB and in DBL+GL ... / Doutor
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Phosphorus release characteristics and quantification of microbial population at different stages of phospho-compost productionMokase, Tsakani Joyce January 2016 (has links)
Thesis (M. Sc. Agriculture (Soil Science)) -- University of Limpopo, 2016 / This study aimed at assess phosphorus (P) solubility and bioavailability from non-reactive Phalaborwa ground phosphate rock (GPR) using thermophilic co-composting technology. Two types of organic wastes (Cattle, CM and poultry manure, PM) were used to produce different mix ratios (5:5, 7:3, 8:2 and 9:1) of phospho-composts. Control compost of both manures without GPR addition were included. Samples of each compost heap were taken at mesophilic, thermophilic, cooling and maturity stages and used for bioquality and chemical tests. Microbial counts, enzyme activity, molecular analysis, and the quatification of different P forms and fractions were carried out on all compost samples. Results showed that the concentration of P measured in the different phospho-composts differed significantly (p < 0.05). The 8:2 mix ratio gave quantitatively higher P concentration in both CM- and PM-based phospho-composts. Organic P form had the lowest concentration when compared to other P forms and fractions while water soluble-P had the highest concentration as compared to other P fractions. The content of actinomycetes showed correlated positively with EC, phosphatase β-glucosidase, fungi and bacteria but negatively correlated with organic P, Ca-P water P and pH. There was a positive and significant correlation between electrical conductivity, enzyme activity (phosphatase, dehydrogenase and β-glucosidase), fungi, actinomycete and P fractions (Bray P1, Ca-P and Pi value). Acid phosphatase activity correlated negatively with water extractable P, organic P and Ca-P contents but revealed a positively significant correlation with bacteria, fungi and actinomycete counts.
Generally higher microbial counts were measured in CM- than PM-based phospho-composts but the concentrations varied with each microbial species. Highest fungi (7.27 CFU g-1) and actinomycete (6.83 CFU g-1) counts were generally recorded in the control composts, which was quantitatively higher in CM- than PM-based phospho-composts. Quantitatively higher enzyme activities were measured across compost types and mix ratios during the cooling phase phospho-compost production; but were statistically comparable to measured values at maturity phase. Acid phosphatase and β-glucosidase enzymes were predominately higher at maturity phase in all cattle manure-based phospho-compost excluding the 5:5 mix ratio. In PM-based phospho-compost, both β-glucosidase and phosphatase were higher at initial phase with PM5:5 , PM9:1 and PM10:0. Dehydrogenase activities were predominately higher at thermophilic and cooling phase from both PM- and CM-based phospho-compost. Results of molecular analysis revealed that Bacillus sp. and Acholeplasma cavigenitalium sp. were dorminant in PM-based phospho-composts while Pseudomonas sp. and Acholeplasma pleciae dorminated the CM-based phospho-composts. In conclusion, results of this study revealed that the type of manure used exerts great influence on the bioquality parameters and the amount of P released.
Key words: Phospho-compost, Compost quality, Enzyme activities, Nutrient cycling, Ground phosphate rock, Phosphorus forms and fractions
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Bisorption of uranium and thoriumTsezos, Marios January 1980 (has links)
No description available.
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Utilization of municipal solid waste compost in horticultureLu, Wenliang. Sibley, Jeffrey Lynn, January 2008 (has links) (PDF)
Dissertation (Ph.D.)--Auburn University, 2008. / Abstract. Includes bibliographic references.
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Experimental vegetation of bottom ash and scrubber sludge at Kansas City Power & Light Company's Lacygne generating stationMulhern, Daniel Wayne. January 1984 (has links)
Call number: LD2668 .T4 1984 M84 / Master of Science
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Investigation of electrochemical combustion plant for rural water disinfection and industrial organic effluent removalCronje, Martin 04 1900 (has links)
Thesis (MScIng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Recent years have seen the development of various treatment methods for the purification
of industrial waste waters due to the increased demand for reduced pollutant
effluents. Aqueous waste streams containing toxic organic compounds are of special
interest, since conventional treatment methods such as biological waste treatment
can not always be used. Other popular treatment methods are often ineffective.
Catalytic oxidation of organic wastes has been investigated since the 1960s with
varying degrees of success. A major problem associated with this method is the high
temperatures and pressures required to improve the activation energies involved.
Electrochemical oxidation has become a popular method in the literature of treating
these wastes, since the applied voltage determines the activation energy, and
therefore the process can often be performed at ambient conditions.
This thesis investigates the capability of a unique reactor system in the treatment
of these wastes. The reactor utilises proton-exchange membrane technology to eliminate
the requirement of conductivity in treated waste streams; thus the membrane
serves as a solid electrolyte. The reactor system has therefore been referred to as a
solid-polymer-electrolyte reactor. Novel metal oxide anodes are responsible for the
oxidation of the organic molecules. These metal oxide catalysts show promise in the
treatment of a wide variety of organic wastes. A SnO2 catalyst doped with ZrO2 is
used as anode in this study. Dopants are added to the catalyst to improve properties
such as catalytic activity and conductivity.
Kinetic data was obtained on a wide range of values for the chosen experimental
parameters (current density and flow rate). Phenol, an organic molecule often referred
to in the literature as model contaminant due to its resistance to oxidation,was also used as contaminant in this study. The use of the reactor system in the disinfection
of water containing selected pathogens, were included in the experimental
work. This kinetic data served in the development of a simple model of the process,
and provided the basis for a full analysis regarding potential scale-up and economic
feasibility.
A requirement of the study was the accurate determination of the various oxidation
breakdown products of phenol. This led to the refinement of an HPLC analytical
method in order to quantitatively determine these products.
The full analysis showed that the current reactor system would not be economically
viable — mainly due to very long reactor lengths required for the complete
removal of all organic material. Both mass transfer and charge transfer at the chosen
experimental conditions influenced the electrochemical oxidation of phenol. High
pressure drops, causing low flow rates in the reactor, accounted for this because of
the narrow flow channels required in the reactor. Some catalyst deactivation was
also suspected to affect the overall reaction, but the full extent of the deactivation
was not investigated thoroughly.
There is still room for improvement in the electrochemical oxidation of organic
wastes. The design of the flow channels, a factor that was not investigated, can
significantly improve efficiency. Another aspect that was not investigated was the
catalyst type. The catalyst has been identified in the literature as the main contributing
factor to the success of the oxidation reaction. A wide variety of metal oxide
catalysts are currently being researched and may improve the kinetics of the process
even further. Further improvement needs to be made on the membrane/electrode
assembly to improve current density distribution.
Every improvement of the process in terms of the reactor design and catalyst will
impact on the economics of the process, thus making the process more competitive
with current treatment technologies. / AFRIKAANSE OPSOMMING: In die afgelope paar dekades, is daar ’n wye verskeidenheid metodes ontwikkel wat
gebruik kan word om industri¨ele afvoer strome te behandel. Hierdie ontwikkeling
het plaasgevind as gevolg van die verhoogde eis aan skoner afvoerstrome. Wateragtige
afvoerstrome wat organiese verbindings bevat, is van besonderse belang omdat
hierdie tipe strome soms besonders moeilik kan wees om te behandel. Gebruiklike
metodes is in die meeste gevalle ongeskik vir behandelings-doeleindes. Katalitiese
oksidasie is sedert die 1960’s gebruik, maar hierdie prosesse benodig dikwels ho¨e
drukke en temperature om suksesvol te wees. Elektrochemiese oksidasie het intussen
’n populˆere behandelingsmetode geword, aangesien die aktiveringsenergie vir die oksidasieproses
hoofsaaklik afhanklik is van die aangewende potensiaal en dus kan die
proses by atmosferiese toestande gebruik word.
In hierdie tesis word die geskiktheid van ’n unieke reaktorstelsel vir water-suiwering
ondersoek. Die reaktor gebruik ’n proton-uitruilings-membraan om die behoefte
vir konduktiwiteit in die water uit te skakel. Die membraan dien dus as ’n
tipe soliede elektroliet en as gevolg hiervan word na die reaktorstelsel verwys as ’n
soliede-polimeer-elektroliet reaktor. Nuwe metaal-oksied anodes word in die reaktor
gebruik aangesien hulle belowende resultate toon in die oksidasie van organiese
verbindings. In die navorsing, is ’n SnO2 katalis wat klein hoeveelhede ZrO2 bevat
gebruik. Oksiede soos ZrO2 word dikwels gebruik om die aktiwiteit en konduktiwiteit
van hierdie kataliste te bevorder.
Kinetiese data is oor ’n wye bereik van parameter waardes ingesamel. Die hoof
parameters in die eksperimentele werk was stroom digtheid en vloeitempo. Fenol,
‘n komponent wat volgens die literatuur in hierdie tipe van werk gebruik word, isas die besoedelende komponent gekies. Die doeltreffendheid van die reaktor in die
ontsmetting van water, wat met ’n verskeidenheid skadelike mikro-organismes besmet
is, is ook getoets. ‘n Eenvoudinge model is opgestel m.b.v. die kinetiese data,
waarna ’n volledige analise met betrekking tot grootskaalse bedryf en ekonomiese
uitvoerbaarheid gedoen is.
‘n Vereiste van die studie was om die konsentrasie van die afbreek-produkte
van die oksidasie akkuraat vas te stel. As gevolg hiervan is ‘n ho¨e-druk-vloeistofchromatografie
analitiese metode verfyn.
Die analise het getoon dat die reaktorstelsel nie ekonomies sou wees nie. Een
van die hoofredes hiervoor is die onrealistiese reaktorlengtes wat benodig sou word.
Resultate het getoon dat die reaksie deur beide massa-oordrag en lading-oordrag
be¨ınvloed word. Ho¨e drukvalle in die reaktor wat gelei het tot lae vloeitempo’s was
hiervoor verantwoordelik. Die deaktivering van die katalis be¨ınvloed waarskynlik die
reaksie, maar die deaktiveringsverskynsel is nie ten volle ondersoek nie.
Die reaktorstelsel kan verder verbeter word deur verskeie elemente van die reaktor
te ondersoek. Die ontwerp van die vloeikanale in die reaktor is nie ondersoek nie en
kan die werksverrigting van die reaktor verhoog. Uit die literatuur is gevind dat die
tipe metaaloksied wat as katalis gebruik word, die reaksie direk be¨ınvloed. Dus kan
navorsing wat tans op die kataliste gedoen word nuwe kataliste na vore bring wat
meer doeltreffend sal wees. Laastens, is die huidige membraan/elektrode samestelling
nog oneffektief en kan die reaktor-opstelling dus nog verbeter word.
Elke verbetering wat op die bogenoemde faktore van die reaktor ontwerp verkry
word, sal die ekomoniese uitvoerbaarheid van die proses be¨ınvloed. So, sal die proses
al meer kompeterend met huidige behandelingsmetodes word.
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