Spelling suggestions: "subject:"coagulationflocculation"" "subject:"autoflocculation""
11 |
Natural organic matter (NOM) and turbidity removal by plant-based coagulants: A reviewOkoro, B. U., Sharifi, S., Jesson, M. A., Bridgeman, John 21 October 2021 (has links)
yes / NOM deteriorates water quality by forming taste, clarification, colour, and odour problems. It also increases coagulant and chlorine consumption which can initiate disinfection by-products harmful to human health. The coagulation-flocculation (CF) technique is an established method commonly employed to remove NOM in water treatment. Plant-based coagulant products (PCPs) derived from plants like the Moringa oleifera (MO) Strychnos potatorum Linn and Opuntia ficus indica, have been studied and proposed as sustainable alternatives to chemical coagulant, like, aluminium sulphate due to their abundant availability, low cost, low sludge volume and disposal cost, and biodegradability. This review paper provides an overview of the most widely studied plant-based coagulants and discusses their NOM and turbidity removal. It investigates recent analytical tools applied in their characterisation and floc morphological studies. The paper also investigates the effects of operating parameters such as coagulant dose, temperature, and pH, on NOM and turbidity removal. It also reviews up-to-date PCPs biophysical properties and CF mechanism and examines the efficiency of their extraction methods in reducing NOM. Finally, it discusses and suggests ways to overcome commercialisation draw-back caused by nutrient addition.
|
12 |
Characterisation of dissolved organic matter to optimise powdered activated carbon and clarification removal efficiencyShutova, Y., Rao, N.R.H., Zamyadi, A., Baker, A., Bridgeman, John, Lau, B., Henderson, R.K. 15 June 2020 (has links)
Yes / The character of dissolved organic matter (DOM) present in drinking water treatment systems greatly impacts its treatability by coagulation–flocculation. Powdered activated carbon dosing has been suggested to enhance DOM removal when combined with coagulation–flocculation. However, optimising powdered activated carbon (PAC) dosing requires further research. In this study, fluorescence spectroscopy combined with parallel factor analysis (PARAFAC) and liquid chromatography with organic carbon detection (LC–OCD) has been used to characterise DOM removal in three ways: (a) coagulation–flocculation–sedimentation without PAC dosing, (b) PAC dosing prior to- and (c) PAC dosing during coagulation–flocculation–sedimentation treatment. It was shown that only coagulation–flocculation–sedimentation preferentially removed biopolymer and humic substance chromatographic fractions and fluorescent DOM, whereas dosing PAC preferentially removed building blocks and low molecular weight neutral chromatographic fractions. The DOM treatability that was achieved when PAC was dosed both prior to- and during coagulation–flocculation–sedimentation was comparable, but higher than what was achieved without any PAC dosing. Introduction of PAC to the coagulation–flocculation–sedimentation process significantly improved DOM removal, with fluorescent components removed by 97%. This study also highlights that a combination of fluorescence spectroscopy and LC–OCD is essential to track the removal of both, fluorescent and non-fluorescent DOM fractions and understand their impacts on DOM treatability when using different treatment processes. Overall, lower residual DOM concentrations were obtained in the treated water when PAC adsorption and the coagulation–flocculation–sedimentation processes were combined when compared to treating the water with only one of the processes, despite differences in source water character of DOM.
|
13 |
Tratamento físico-químico de lixiviado de aterro sanitário pré-tratado por processo biológico aeróbio. / Physico-chemical treatment of landfill leachate from pre-treated by aerobic biological process.Amaral, Mailer Sene 22 May 2009 (has links)
Lixiviados de aterros sanitários apresentam altas concentrações de nitrogênio amoniacal e matéria orgânica, além de outros poluentes, que não permitem seu descarte no meio ambiente, sem um prévio tratamento. Lixiviados de aterros sanitários mais antigos, com matéria orgânica mais estabilizada, apresentam grande potencial poluidor, principalmente devido à presença de substâncias recalcitrantes que, usualmente, não são removidas através de tratamento biológico, necessitando, portanto, da aplicação de um pós-tratamento. A presente pesquisa objetivou aplicar o tratamento físico-químico a dois efluentes de sistemas biológicos de tratamento. O primeiro sistema era constituído de um reator de lodo ativado operado em bateladas seqüenciais (70 Litros) cujo efluente era submetido à processo de coagulaçãofloculação usando sais de ferro e alumínio, para remoção da matéria orgânica recalcitrante. Operou-se, em paralelo, uma lagoa aerada, em escala de bancada, dimensionada para remoção da matéria orgânica biodegradável cujo efluente era submetido a processo de precipitação química para remoção de amônia, através da formação do mineral estruvita (MgNH4PO4.6H2O). Os resultados obtidos demonstraram que o cloreto férrico (FeCl3) foi o coagulante mais apropriado sob o ponto de vista econômico, embora, dosagens elevadas (1.160 mg FeCl3/L), frente a 2.465 mg Al2(SO4)3.6H2O/L tenham sido requeridas para o alcance de remoções da matéria orgânica recalcitrante. Com a aplicação de FeCl3 o pH ótimo de coagulação foi próximo de 4,0 e para o Al2(SO4)3; por volta de 5,0. Ao longo dos testes, avaliouse a influência das condições de mistura sobre os fenômenos físico-químicos. Os resultados demonstram que, para o despejo estudado, o gradiente de velocidades e o tempo de mistura não exercem influência sobre os fenômenos de coagulaçãofloculação. Quanto à precipitação química da amônia na forma do mineral estruvita, as melhores remoções (~ 90%) foram alcançadas quando o limite de solubilidade do mineral estruvita foi excedido, para tanto se faz necessária aplicar uma razão molar igual a 1,5:1:1,4 entre os íons envolvidos (Mg+2:NH4 +:PO4 -3). Entretanto, o efluente final desse sistema apresentou uma concentração residual de fósforo solúvel superior a 12 mg P-PO4 -3/L, o que o torna pouco recomendável para fins práticos. / Landfill leachates present high ammonia and organic matter concentrations, besides other pollutants, which do not allow its discharge to the environment without a previous treatment. Older landfill leachates, with more stabilized organic matter, present great pollutant potential, mainly due to the presence of recalcitrant substances that not often are removed by biological treatment and need the application of a post-treatment. The present research aimed to apply the physicochemical treatment for two biological wastewater treatment plant effluents. The first one was constituted by an activated sludge (sequence batch reactor - 70 liters), which effluent was submitted to a coagulation-flocculation process, using iron and aluminum salts, for recalcitrant organic matter removal. A lab scale aerated lagoon was operated in parallel. The lagoon was dimensioned for biodegradable organic matter removal, which effluent was submitted to a chemical precipitation process for ammonia removal (formation of the mineral struvite (MgNH4PO4.6H2O).The results showed that the ferric chloride (FeCl3) was the more appropriated coagulant considering the economic point of view, however high dosages (1,160 mg FeCl3/L) comparing with 2.465 mg Al2(SO4)3.6H2O/L had been required to achieve recalcitrant organic matter removal. Applying FeCl3, the optimum pH was of the order of 4.0 and for Al2(SO4)3, approximately 5.0. During the tests, the influence of the mixture conditions on the physicochemical phenomena was evaluated. The results demonstrated that the velocities gradient and the mixture time do not influenced the coagulation-flocculation phenomena. Regarding to the chemical precipitation of ammonia in struvite form, the better removals (~ 90%) were achieved when the solubility limit of the mineral was exceeded. Due to this fact, it was necessary to apply a molar rate of 1.5:1:1.4 between the ions (Mg+2:NH4 +:PO4 -3). Nevertheless, the final effluent of this system presented a residual soluble phosphorus concentration higher than 12 mg P-PO4 -3/L, hence it is not recommended for practical purposes.
|
14 |
Aplicação de sulfato de alumínio e taninos vegetais na coagulação-floculação de efluentes de curtumeAnjos, Patrícia Schacker dos January 2016 (has links)
A aplicação de sais de alumínio para tratamento de efluentes é questionada devido a possíveis impactos nocivos aos seres humanos e organismos vivos, em decorrência de residuais de alumínio remanescentes na água tratada e das quantidades de lodo sedimentado que contém o metal. Portanto, o uso combinado de sais metálicos e taninos vegetais, a fim de reduzir as concentrações do primeiro, aplicadas na coagulação-floculação de contaminantes dos efluentes é importante, inclusive pelas vantagens do uso de taninos, como polímeros orgânicos biodegradáveis. Assim, este trabalho visa aplicar sulfato de alumínio e taninos, em uso individual e em combinação, para remoção de contaminantes por meio de coagulação-floculação. Os ensaios foram realizados com três efluentes, um com elevada carga orgânica, um com baixa carga orgânica e um efluente de acabamento, todos de um mesmo curtume que realiza operações de acabamento molhado a acabamento final de couro wet-blue. No efluente de alta carga orgânica, foram testados 5 tipos de taninos em seis dosagens, e os taninos Tanfloc SM e Tanfloc SH, com melhor eficiência, também foram testados no efluente de menor carga orgânica, assim como o sulfato de alumínio, nas mesmas concentrações utilizadas inicialmente a fim de apresentar os resultados atingidos em efluentes com características de altas e baixas dosagens de químicos Após, foram realizadas combinações de sulfato de alumínio com Tanfloc SM e Tanfloc SH, em diferentes concentrações, e realizados ensaios nos três efluentes, com o intuito de apresentar a eficiência do uso combinado destes produtos em diferentes características de efluentes e verificar a redução das dosagens de sulfato de alumínio. Os melhores resultados obtidos na aplicação combinada de sulfato de alumínio e taninos, mostraram remoção de cor, turbidez e COT estatisticamente iguais à aplicação do uso individual destes, porém utilizando menores dosagens de sulfato de alumínio na composição. Assim, conclui-se que é possível realizar, de forma eficiente e satisfatória, o uso de misturas de sulfato de alumínio com taninos de forma a reduzir as dosagens de sulfato de alumínio, obtendo bons resultados de remoção de cor, turbidez e remoções superiores de COT quando comparadas com a aplicação de todos os coagulantes/floculantes individualmente. / The use of aluminum salts for the treatment of effluents is questioned due to possible harmful impacts on humans and living organisms with aluminum residuals remaining in the treated water and the quantities of sedimented sludge containing the metal. Therefore, the combined use of metal salts and vegetable tannins, in order to reduce the concentrations of the former, applied in the coagulation-flocculation of effluent contaminants is important, including the advantages of the use of tannins, such as biodegradable organic polymers. Thus, this work aims to apply aluminum sulfate and tannins, in individual use and in combination, to remove contaminants by means of coagulation-flocculation. The tests were carried out with three effluents, one with high organic load, one with low organic load and one finishing effluent, all from the same tannery that performs wet finishing operations with the final wet-blue leather finish. In the high organic matter effluent, five types of tannins were tested in six dosages, and Tanfloc SM and Tanfloc SH tannins with better efficiency were also tested in the less organic effluent as well as aluminum sulfate in the same concentrations used in order to present the results achieved in effluents with characteristics of high and low chemical dosages Afterwards, combinations of aluminum sulphate with Tanfloc SM and Tanfloc SH were carried out in different concentrations, and tests were carried out on the three effluents, in order to show the efficiency of the combined use of these products in different effluent characteristics and verify the reduction of the dosages of aluminum sulfate. The best results obtained in the combined application of aluminum sulphate and tannins showed color removal, turbidity and TOC statistically equal to the application of the individual use of these, but using lower dosages of aluminum sulphate in the composition. Thus, it is concluded that it is possible to efficiently and satisfactorily carry out the use of aluminum sulphate mixtures with tannins in order to reduce the dosages of aluminum sulphate, obtaining good results of color removal, turbidity and higher removals of COT when compared to the application of all coagulants/flocculants individually.
|
15 |
Investigation of alternative colouration processing medium for textiles and novel filtration media for recycling of textile effluentUddin, Md Abbas January 2014 (has links)
The aim of this research was to find a suitable alternative medium of scarce freshwater for textile dyeing, and to recycle and reuse the dyebath using a combined coagulation/flocculation and novel filter media. Simulated seawater (SSW) was tested as the alternative dyeing medium with a salt concentration of 3.5% where NaCl was the major component. Fibre/dye systems of wool/acid and metal complex, wool/reactive, polyester/disperse, nylon/acid and metal complex, and acrylic/cationicdyes were tested in simulated seawater and the performances of dyed fabric were compared to conventional dyeing system of distilled water (DSW). The study found that commercial dyeing processes were robust and can be practically transferable into the seawater medium. The dye exhaustions, build-up, colour characteristics, and fastness to wash, cross-staining, rub and light were satisfactory within the dye ranges studied, which covers commercially available monochromatic Red, Yellow and Blue at light, medium and deep shades. Although SEM micrographs didn't show any presence of salt, a typical wash-off process of 1gL-1 with a non-ionic detergent at 70°C was sufficient to remove any salt that could be present on the surface or sub-surface of the dyed fabric. At room temperature, some acid and metal complex dyes were only partially soluble in SSW but this improved with gentle heating and addition of levelling agents. At dyeing temperatures near the boil, these dyes were completely soluble. A saturation limit was found to be existed for acrylic dyeing of cationic dyes over 1.0% o.m.f. depth. Although ionic interaction was the dominant mechanism for dyeing of wool, nylon and acrylic fibre with acid, metal complex and cationic dyes, the adsorption in highly saline dyebath most likely depended on the combined effects of ionic and physical/hydrophobic interaction. The resultant effect was higher dye exhaustion and consequently higher colour difference in SSW for some dyes. Reactive dyes were known to be sensitive to hardness of water but this study confirmed that reactive dye could be an alternative for deep dyeing for wool fibre in SSW. Reactive dyeing of wool followed a similar mechanism of gradual phase transfer as was observed for disperse dyeing of hydrophobic fibres over 3.0% o.m.f. depth. In contrast disperse dyeing of polyester produced consistent results for all dyes but some black dyeings produced superior colour strength in SSW. The build-up of colour in SSW compared to DSW can be different depending on the application level. To improve permeate flux by reducing membrane fouling, a number of surface modification were carried out to introduce fluorine based functional groups. Gaseous fluorination, fluorocarbon finish (FC) and plasma polymerisation were performed to introduce hydrophilic and oleophobic properties on supplied Azurtex membrane. The fluorinated Azurtex media exhibited increased wettability although it was not directly proportional to an increase in the fluorination level and treatment time. The water and oil repellency of FC and plasma treated filter media provided a reasonable level of repellency while the contact angle remained in the range of 130 to 145°. Pre-fluorination of filter media before FC treatment didn't change the water and oil repellency. Surface characterisation of Azurtex media was performed with ATR-FTIR, XPS and SEM. An increased level of fluorination at 10%F2 and prolonged exposure showed a degradation of the surface along with colour change. The fluorinated, FC treated and plasma polymerised membrane showed a typical C-F stretching vibration in the region of 1100-1350 cm-1 and weakly at 400-800cm-1. The XPS study showed a gradual increase in the -CF2 and -CF3 functionality signal intensities that resulted in imparting hydrophobicity The benchmarking of these modified Azurtex filter media against newly developed materials proved that plasma treatment improved the flow, reduced turbidity and provided an easy cake removal compared to fluorinated and FC finished filter media. Recycling of exhausted dyebath using a dual component coagulant/flocculant system of Pluspac 2000 and polyanionic Hydrosolanum protein derivative (HPSS) and microfiltration with Azurtex filter media was investigated. The process parameters such as pH and dosage of coagulants/flocculants were very critical during coagulation/flocculation for overall colour removal. The trial with model dye solution in SSW showed that the system worked in the saline environment with a relatively high concentration ratio of coagulant/flocculants but highly depends on the class and structure of dyes. Maximum colour removal was achieved for Lanaset Blue 2R and Sandolan Red MF-GRLN dye and was 89% and 61%, respectively, based on a ratio of 15:10 and 15:15 for PP2000: HPSS at pH 4.0 and 5.0, respectively. The reuse of the dyebath with combined physico-chemical and micro-filtration treatment was demonstrated to be feasible with wool/acid dye system. The colour profile of Lanaset Blue 2R and Sandolan Red MF-GRLN dyed fabrics up to 12th dyeing, with dyebath filtration undertaken after the 3rd /4th/5th reuse of the dyebath, remained comparable to dyeing in fresh baths. The colour strength, K/S, decreased after every filtration and the colour differences, DeltaE increased, but reversed in subsequent dyeing in reused dyebath. The wash and dry rub fastness of the dyed fabrics remained comparable and significant improvements in the abrasion resistance were observed.
|
16 |
Tratamento físico-químico de lixiviado de aterro sanitário pré-tratado por processo biológico aeróbio. / Physico-chemical treatment of landfill leachate from pre-treated by aerobic biological process.Mailer Sene Amaral 22 May 2009 (has links)
Lixiviados de aterros sanitários apresentam altas concentrações de nitrogênio amoniacal e matéria orgânica, além de outros poluentes, que não permitem seu descarte no meio ambiente, sem um prévio tratamento. Lixiviados de aterros sanitários mais antigos, com matéria orgânica mais estabilizada, apresentam grande potencial poluidor, principalmente devido à presença de substâncias recalcitrantes que, usualmente, não são removidas através de tratamento biológico, necessitando, portanto, da aplicação de um pós-tratamento. A presente pesquisa objetivou aplicar o tratamento físico-químico a dois efluentes de sistemas biológicos de tratamento. O primeiro sistema era constituído de um reator de lodo ativado operado em bateladas seqüenciais (70 Litros) cujo efluente era submetido à processo de coagulaçãofloculação usando sais de ferro e alumínio, para remoção da matéria orgânica recalcitrante. Operou-se, em paralelo, uma lagoa aerada, em escala de bancada, dimensionada para remoção da matéria orgânica biodegradável cujo efluente era submetido a processo de precipitação química para remoção de amônia, através da formação do mineral estruvita (MgNH4PO4.6H2O). Os resultados obtidos demonstraram que o cloreto férrico (FeCl3) foi o coagulante mais apropriado sob o ponto de vista econômico, embora, dosagens elevadas (1.160 mg FeCl3/L), frente a 2.465 mg Al2(SO4)3.6H2O/L tenham sido requeridas para o alcance de remoções da matéria orgânica recalcitrante. Com a aplicação de FeCl3 o pH ótimo de coagulação foi próximo de 4,0 e para o Al2(SO4)3; por volta de 5,0. Ao longo dos testes, avaliouse a influência das condições de mistura sobre os fenômenos físico-químicos. Os resultados demonstram que, para o despejo estudado, o gradiente de velocidades e o tempo de mistura não exercem influência sobre os fenômenos de coagulaçãofloculação. Quanto à precipitação química da amônia na forma do mineral estruvita, as melhores remoções (~ 90%) foram alcançadas quando o limite de solubilidade do mineral estruvita foi excedido, para tanto se faz necessária aplicar uma razão molar igual a 1,5:1:1,4 entre os íons envolvidos (Mg+2:NH4 +:PO4 -3). Entretanto, o efluente final desse sistema apresentou uma concentração residual de fósforo solúvel superior a 12 mg P-PO4 -3/L, o que o torna pouco recomendável para fins práticos. / Landfill leachates present high ammonia and organic matter concentrations, besides other pollutants, which do not allow its discharge to the environment without a previous treatment. Older landfill leachates, with more stabilized organic matter, present great pollutant potential, mainly due to the presence of recalcitrant substances that not often are removed by biological treatment and need the application of a post-treatment. The present research aimed to apply the physicochemical treatment for two biological wastewater treatment plant effluents. The first one was constituted by an activated sludge (sequence batch reactor - 70 liters), which effluent was submitted to a coagulation-flocculation process, using iron and aluminum salts, for recalcitrant organic matter removal. A lab scale aerated lagoon was operated in parallel. The lagoon was dimensioned for biodegradable organic matter removal, which effluent was submitted to a chemical precipitation process for ammonia removal (formation of the mineral struvite (MgNH4PO4.6H2O).The results showed that the ferric chloride (FeCl3) was the more appropriated coagulant considering the economic point of view, however high dosages (1,160 mg FeCl3/L) comparing with 2.465 mg Al2(SO4)3.6H2O/L had been required to achieve recalcitrant organic matter removal. Applying FeCl3, the optimum pH was of the order of 4.0 and for Al2(SO4)3, approximately 5.0. During the tests, the influence of the mixture conditions on the physicochemical phenomena was evaluated. The results demonstrated that the velocities gradient and the mixture time do not influenced the coagulation-flocculation phenomena. Regarding to the chemical precipitation of ammonia in struvite form, the better removals (~ 90%) were achieved when the solubility limit of the mineral was exceeded. Due to this fact, it was necessary to apply a molar rate of 1.5:1:1.4 between the ions (Mg+2:NH4 +:PO4 -3). Nevertheless, the final effluent of this system presented a residual soluble phosphorus concentration higher than 12 mg P-PO4 -3/L, hence it is not recommended for practical purposes.
|
17 |
Impacto da coagulação química na remoção de compostos orgânicos em efluente tratado por processo de lodos ativados. / Impact of coagulation flocculation process on the removal of organic compounds from secondary effluent from activates sludge treatment.Natália Rodrigues Guimarães 08 November 2016 (has links)
Os compostos (coloidais, suspensos e solúveis) presentes na água residual possuem diferentes características físico-químicas e diferentes massas moleculares. Pesquisadores têm se dedicado ao entendimento mais específico da parte solúvel do efluente. O fracionamento das substâncias orgânicas em diferentes classes e diferentes tamanhos é um dos métodos utilizados para a caracterização dos compostos orgânicos da água residual. Acredita-se que este método possa detectar as alterações nos valores residuais dos compostos orgânicos de forma mais precisa que os métodos tradicionais, i.e. DBO e DQO. Sendo assim, e sabendo do crescente uso dos projetos de pós-tratamento dos efluentes de ETE e reúso destes, fica a clara a avaliação da eficiência dos processos de pós-tratamento e a importância da quantificação e caracterização da matéria orgânica residual no efluente pós-tratado. Os objetivos deste projeto de pesquisa foram avaliar a remoção da carga orgânica residual no efluente do tratamento biológico do processo de lodo ativado da ETE Jesus Netto, utilizando diferentes parâmetros de coagulação/floculação utilizando cloreto férrico, sulfato de alumínio e cloreto de polialumínio como coagulantes, e análise de carbono orgânico dissolvido juntamente com a técnica de distribuição da massa molecular para avaliar essa remoção. As análises mostraram uma redução dos compostos orgânicos presentes no efluente secundário, em termos de carbono orgânico dissolvido, da ordem de 45% para o cloreto férrico e 38% para os sais de alumínio. A distribuição da massa molecular também sofreu alterações, notando-se o aumento dos compostos de menor massa molecular e a redução dos compostos de maior massa molecular. Os resultados corroboram com outros estudos realizados com efluentes secundários e águas de abastecimento sobre o impacto dos processos físico-químicos na distribuição da massa molecular. / The compounds (colloidal, suspended and soluble) present in the waste water have different physicochemical characteristics and different molecular masses. Researchers have dedicated themselves to the more specific understanding of the soluble part of the effluent. The fractionation of the organic substances in different classes and different sizes is a method widely used for the characterization of the organic compounds of the residual water. It´s believed that this method can detect changes of organic compounds residual values more accurately than traditional methods, i.e. biological oxygen demand and chemical oxygen demand. Therefore, knowing the increasing use of WWTP effluent after post-treatment processes and their reuse, it is clear that the evaluation of the post-treatment efficiency and the importance of the quantification and characterization of the residual organic matter in the post-treated effluent. The objectives of this research project were to evaluate the removal of the residual organic matter in the effluent from the biological treatment of the activated sludge process of the Jesus Netto WWTP using different coagulation/flocculation parameters with ferric chloride, aluminium sulfate and polyaluminum chloride (PAC) as coagulants, and dissolved organic carbon and molecular mass distribution analyses to evaluate the organic matter removal. The analyzes showed a reduction of the organic matter present in the secondary effluent, in terms of dissolved organic carbon, up to 45% for ferric chloride and 38% for aluminum salts. The distribution of the molecular mass also changed, with the increase of the compounds of lower molecular mass and the reduction of the compounds of higher molecular mass. The results corroborate with other studies carried out with secondary effluents and water supply on the impact of physicochemical processes on the molecular weight distribution.
|
18 |
Uso de adsorventes a base de lodo de curtume e biomassa fúngica para remoção de corantes da indústria coureiraPuchana-Rosero, Mayerly Johana January 2017 (has links)
A presente pesquisa descreve o preparo, caracterização e aplicação de novos adsorventes aplicados ao tratamento de efluentes contendo corantes. Os adsorventes produzidos neste estudo foram: Carvão ativado produzido por pirólise assistida por micro-ondas (AMWCST), a partir de um lodo coletado em uma Estação de Tratamento de Efluentes de curtume; e, biomassa fúngica tratada termicamente (BTV) a partir do fungo Trametes sp SC-10, os quais foram caracterizados de acordo a suas propriedades de textura e química de superfície e foram aplicados na remoção de corantes em solução aquosa e efluentes. Nesta pesquisa também se avaliou a eficiência do processo combinado entre coagulação-floculação e adsorção usando o AMWCST. Em suas propriedades estruturais, o AMWCST apresentou uma área superficial BET de 491,0 m2 g-1 e um volume total do poro de 0,440 cm3g-1, com distribuição de tamanho de poro majoritariamente mesoporosa; entretanto o BTV apresentou baixa área superficial destacando-se a formação de mesoporos. Foram estudados os equilíbrios e cinéticas de adsorção e sua correlação com modelos empíricos, para os sistemas AMWCST/PA-210 (Preto Ácido 210), e VA-357(Vermelho Ácido 357) e BTV/ AA-161 (Azul ácido 161). Para os dois primeiros sistemas empregando carvão ativado, a isoterma de adsorção de Liu foi a que descreveu melhor os dados de adsorção com capacidades máximas de 1108 mg g-1 e 589,5 mg g-1 a 298 K para PA-210 e VA-357. Para os estudos cinéticos, o modelo de ordem fraccionário de Avrami foi o melhor modelo ajustado para os dados experimentais. A BTV no entanto, mostrou uma capacidade máxima de biossorção de AA-161 de 221,7 mg g-1 a 303 K. O modelo de Langmuir foi o modelo que melhor descreveu os dados experimentais de equilibrios de biossorção e o Modelo Fraccionário de Avrami foi o que melhor descreveu a cinética de biossorção para o corante. A eficiência de remoção do adsorvente AMWCST no efluente sintético simulado foi de 93,79% e do BTV em um efluente simulado similar ao do processo de acabamento molhado de couro foi de 89,47%, indicando que a BTV é também um bom biossorvente para o tratamento de efluentes industriais. Finalmente, enquanto ao estudo de combinação de processos de coagulação-floculação com adsorção usando o AMWCST, este mostrou resultados eficazes na remoção do corante PA-210, em efluentes do processo de acabamento molhado, obtendo 85,20% de remoção do corante em comparação com o carvão comercial, o qual apresentou 88,64%. Além disso, utilizando o AMWCST, obtiveram-se reduções de 68,44%, 13,44% e 42,81% para COT, sódio total e amônio. / The present research describes the preparation, characterization and application of new adsorbents for the treatment of effluents contaminated with dyes. An adsorbent was activated carbon produced by pyrolysis microwave-assisted (AMWCST), from a sludge collected at a tannery Treatment Plant; The other adsorbent was a thermally treated fungal biomass (BTV) from Trametes sp. SC-10 fungi, which were characterized according to their texture and surface chemistry properties and were applied in the removal of dyes in aqueous solution and effluents. In this research, the efficiency of the combined coagulation-flocculation and adsorption process using the AMWCST was also evaluated. As for the texture properties, the AMWCST presented a BET surface area of 491.0 m2g-1 and a total pore volume of 0.440 cm3g-1, with mesoporous pore size distribution; However, BTV presented low surface area, highlighting the formation of mesopores. As for adsorption equilibria and kinetics and their correlation with theoretical models, for the AMWCST / AB-210, and AR-357 and BTV/AB-161 systems. For the first two systems using activated carbon, the Liu adsorption isotherm was the model that best described the adsorption data with maximum capacities of 1108 mg g-1 and 589,5 mg g-1 at 298 K for AB- 210 and AR- 357. For the kinetic studies, the Avrami fractional order model was the best-fit model for the experimental data. BTV however, showed a maximum AB-161 biosorption capacity of 221.7 mg g-1 at 303K. The Langmuir model was the model that best described the experimental data of biosorption equilibria and the Avrami Fractional Model best described the kinetics of biosorption for the dye. The adsorption efficiency of the AMWCTS in the synthetic simulated effluent was 93.79% and the BTV in a simulated effluent similar to that of the wet-end process in the leather industry was 89.47%, indicating that BTV is also a good biosorbent for the treatment of industrial effluents. Finally, while studying the combination of coagulation-flocculation processes with adsorption using the AMWCST, it showed efficient results in the removal of the AB-210 dye in wet-end process effluents, obtaining 85.20% dye removal compared with commercial activated carbon, which had 88.64%. In addition, using AMWCST, reductions of 68.44%, 13.44% and 42.81% were obtained for TOC, total sodium and ammonium.
|
19 |
Aplicação de sulfato de alumínio e taninos vegetais na coagulação-floculação de efluentes de curtumeAnjos, Patrícia Schacker dos January 2016 (has links)
A aplicação de sais de alumínio para tratamento de efluentes é questionada devido a possíveis impactos nocivos aos seres humanos e organismos vivos, em decorrência de residuais de alumínio remanescentes na água tratada e das quantidades de lodo sedimentado que contém o metal. Portanto, o uso combinado de sais metálicos e taninos vegetais, a fim de reduzir as concentrações do primeiro, aplicadas na coagulação-floculação de contaminantes dos efluentes é importante, inclusive pelas vantagens do uso de taninos, como polímeros orgânicos biodegradáveis. Assim, este trabalho visa aplicar sulfato de alumínio e taninos, em uso individual e em combinação, para remoção de contaminantes por meio de coagulação-floculação. Os ensaios foram realizados com três efluentes, um com elevada carga orgânica, um com baixa carga orgânica e um efluente de acabamento, todos de um mesmo curtume que realiza operações de acabamento molhado a acabamento final de couro wet-blue. No efluente de alta carga orgânica, foram testados 5 tipos de taninos em seis dosagens, e os taninos Tanfloc SM e Tanfloc SH, com melhor eficiência, também foram testados no efluente de menor carga orgânica, assim como o sulfato de alumínio, nas mesmas concentrações utilizadas inicialmente a fim de apresentar os resultados atingidos em efluentes com características de altas e baixas dosagens de químicos Após, foram realizadas combinações de sulfato de alumínio com Tanfloc SM e Tanfloc SH, em diferentes concentrações, e realizados ensaios nos três efluentes, com o intuito de apresentar a eficiência do uso combinado destes produtos em diferentes características de efluentes e verificar a redução das dosagens de sulfato de alumínio. Os melhores resultados obtidos na aplicação combinada de sulfato de alumínio e taninos, mostraram remoção de cor, turbidez e COT estatisticamente iguais à aplicação do uso individual destes, porém utilizando menores dosagens de sulfato de alumínio na composição. Assim, conclui-se que é possível realizar, de forma eficiente e satisfatória, o uso de misturas de sulfato de alumínio com taninos de forma a reduzir as dosagens de sulfato de alumínio, obtendo bons resultados de remoção de cor, turbidez e remoções superiores de COT quando comparadas com a aplicação de todos os coagulantes/floculantes individualmente. / The use of aluminum salts for the treatment of effluents is questioned due to possible harmful impacts on humans and living organisms with aluminum residuals remaining in the treated water and the quantities of sedimented sludge containing the metal. Therefore, the combined use of metal salts and vegetable tannins, in order to reduce the concentrations of the former, applied in the coagulation-flocculation of effluent contaminants is important, including the advantages of the use of tannins, such as biodegradable organic polymers. Thus, this work aims to apply aluminum sulfate and tannins, in individual use and in combination, to remove contaminants by means of coagulation-flocculation. The tests were carried out with three effluents, one with high organic load, one with low organic load and one finishing effluent, all from the same tannery that performs wet finishing operations with the final wet-blue leather finish. In the high organic matter effluent, five types of tannins were tested in six dosages, and Tanfloc SM and Tanfloc SH tannins with better efficiency were also tested in the less organic effluent as well as aluminum sulfate in the same concentrations used in order to present the results achieved in effluents with characteristics of high and low chemical dosages Afterwards, combinations of aluminum sulphate with Tanfloc SM and Tanfloc SH were carried out in different concentrations, and tests were carried out on the three effluents, in order to show the efficiency of the combined use of these products in different effluent characteristics and verify the reduction of the dosages of aluminum sulfate. The best results obtained in the combined application of aluminum sulphate and tannins showed color removal, turbidity and TOC statistically equal to the application of the individual use of these, but using lower dosages of aluminum sulphate in the composition. Thus, it is concluded that it is possible to efficiently and satisfactorily carry out the use of aluminum sulphate mixtures with tannins in order to reduce the dosages of aluminum sulphate, obtaining good results of color removal, turbidity and higher removals of COT when compared to the application of all coagulants/flocculants individually.
|
20 |
Uso de adsorventes a base de lodo de curtume e biomassa fúngica para remoção de corantes da indústria coureiraPuchana-Rosero, Mayerly Johana January 2017 (has links)
A presente pesquisa descreve o preparo, caracterização e aplicação de novos adsorventes aplicados ao tratamento de efluentes contendo corantes. Os adsorventes produzidos neste estudo foram: Carvão ativado produzido por pirólise assistida por micro-ondas (AMWCST), a partir de um lodo coletado em uma Estação de Tratamento de Efluentes de curtume; e, biomassa fúngica tratada termicamente (BTV) a partir do fungo Trametes sp SC-10, os quais foram caracterizados de acordo a suas propriedades de textura e química de superfície e foram aplicados na remoção de corantes em solução aquosa e efluentes. Nesta pesquisa também se avaliou a eficiência do processo combinado entre coagulação-floculação e adsorção usando o AMWCST. Em suas propriedades estruturais, o AMWCST apresentou uma área superficial BET de 491,0 m2 g-1 e um volume total do poro de 0,440 cm3g-1, com distribuição de tamanho de poro majoritariamente mesoporosa; entretanto o BTV apresentou baixa área superficial destacando-se a formação de mesoporos. Foram estudados os equilíbrios e cinéticas de adsorção e sua correlação com modelos empíricos, para os sistemas AMWCST/PA-210 (Preto Ácido 210), e VA-357(Vermelho Ácido 357) e BTV/ AA-161 (Azul ácido 161). Para os dois primeiros sistemas empregando carvão ativado, a isoterma de adsorção de Liu foi a que descreveu melhor os dados de adsorção com capacidades máximas de 1108 mg g-1 e 589,5 mg g-1 a 298 K para PA-210 e VA-357. Para os estudos cinéticos, o modelo de ordem fraccionário de Avrami foi o melhor modelo ajustado para os dados experimentais. A BTV no entanto, mostrou uma capacidade máxima de biossorção de AA-161 de 221,7 mg g-1 a 303 K. O modelo de Langmuir foi o modelo que melhor descreveu os dados experimentais de equilibrios de biossorção e o Modelo Fraccionário de Avrami foi o que melhor descreveu a cinética de biossorção para o corante. A eficiência de remoção do adsorvente AMWCST no efluente sintético simulado foi de 93,79% e do BTV em um efluente simulado similar ao do processo de acabamento molhado de couro foi de 89,47%, indicando que a BTV é também um bom biossorvente para o tratamento de efluentes industriais. Finalmente, enquanto ao estudo de combinação de processos de coagulação-floculação com adsorção usando o AMWCST, este mostrou resultados eficazes na remoção do corante PA-210, em efluentes do processo de acabamento molhado, obtendo 85,20% de remoção do corante em comparação com o carvão comercial, o qual apresentou 88,64%. Além disso, utilizando o AMWCST, obtiveram-se reduções de 68,44%, 13,44% e 42,81% para COT, sódio total e amônio. / The present research describes the preparation, characterization and application of new adsorbents for the treatment of effluents contaminated with dyes. An adsorbent was activated carbon produced by pyrolysis microwave-assisted (AMWCST), from a sludge collected at a tannery Treatment Plant; The other adsorbent was a thermally treated fungal biomass (BTV) from Trametes sp. SC-10 fungi, which were characterized according to their texture and surface chemistry properties and were applied in the removal of dyes in aqueous solution and effluents. In this research, the efficiency of the combined coagulation-flocculation and adsorption process using the AMWCST was also evaluated. As for the texture properties, the AMWCST presented a BET surface area of 491.0 m2g-1 and a total pore volume of 0.440 cm3g-1, with mesoporous pore size distribution; However, BTV presented low surface area, highlighting the formation of mesopores. As for adsorption equilibria and kinetics and their correlation with theoretical models, for the AMWCST / AB-210, and AR-357 and BTV/AB-161 systems. For the first two systems using activated carbon, the Liu adsorption isotherm was the model that best described the adsorption data with maximum capacities of 1108 mg g-1 and 589,5 mg g-1 at 298 K for AB- 210 and AR- 357. For the kinetic studies, the Avrami fractional order model was the best-fit model for the experimental data. BTV however, showed a maximum AB-161 biosorption capacity of 221.7 mg g-1 at 303K. The Langmuir model was the model that best described the experimental data of biosorption equilibria and the Avrami Fractional Model best described the kinetics of biosorption for the dye. The adsorption efficiency of the AMWCTS in the synthetic simulated effluent was 93.79% and the BTV in a simulated effluent similar to that of the wet-end process in the leather industry was 89.47%, indicating that BTV is also a good biosorbent for the treatment of industrial effluents. Finally, while studying the combination of coagulation-flocculation processes with adsorption using the AMWCST, it showed efficient results in the removal of the AB-210 dye in wet-end process effluents, obtaining 85.20% dye removal compared with commercial activated carbon, which had 88.64%. In addition, using AMWCST, reductions of 68.44%, 13.44% and 42.81% were obtained for TOC, total sodium and ammonium.
|
Page generated in 0.1495 seconds