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The Effects of TOC on Settling Velocity and Floc Formation Using Alum and Lime as CoagulantsDunn, Michael T. 01 January 1982 (has links) (PDF)
No description available.
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Estudo das condições de coagulação/flogulação para remoção do catalisador TiO2 do meio reacional após fotodegradação da carga orgânicaSantos, Jomilson Moraes dos [UNESP] 12 April 2006 (has links) (PDF)
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santos_jm_me_bauru.pdf: 549067 bytes, checksum: 7489ebe71b862060486033eb00f03299 (MD5) / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico do Maranhão (FAPEMA) / Esse estudo investigou a cinética de coagulação floculação do TiO2 em suspensão aquosa de baixa força iônica (água destilada)e força iônica média (água de abastecime to público),em função do pH e da adição de sulfato de alumínio. A coagulação floculação do TiO2 ocorre quando o pH é ajustado próximo ao pH do potencial isoelétrico, pela compressão da camada de difusão ou pela adsorção hidrólise com íons Al 3+ . Em suspensões de TiO2 com baixa força iônica,a coagulação ocorre a um determinado pH (4,0 e 7,0), uma vez que ele depende basicamente da superfície do óxido. Com adição de um coadjuvante de sedimentação (por ex. sulfato de alumínio), a qual a força iônica é alta,a coagulação floculação ocorre muito rápido. O tempo de decantação do material em suspensão foi de 2:00 h, foi comparada a cinética de sedimentação da decantação simples com a realizada em Jar Test sob a influência de agitação rápida (eletrocinético) e lenta (ortocinético) antes de permitir a sedimentação. O melhor desempenho foi em Jar Test,turbidez final de 10 NTU. / This study investigated the coagulation-flocculation kinetics of TiO2 in an aqueous Suspension of low-strength ionic solution (distilled water) and a medium strength ionic solution (tap water) as a function of pH and of the addition of aluminum sulfate. Coagulation-flocculation of TiO2 occurs when the pH is adjusted close to the isoelectric potential (iep), by compression of the diffusion layer or by adsorption-hydrolysis with Al 3+ ions. In TiO2 suspensions with low electric strength,coagulation takes place at certain pH (4,0 a d 7,0) since it depends basically on the oxide surface.With the addition of sedimentation aid (e.g.,aluminum sulfate), in which the ionic strength is high, coagulation-flocculation, takes place very fast. The decantation time of the material in suspension was of 2h. The sedimentation kinetic of the simple decantation was compared to that carried out in Jar Test under influence of fast stirring (electrokinetic) and slow stirring (ortokinetic) before sedimentation set up.The best performance was in Jar Test,final turbidez of 10 NTU.
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Estudo das condições de coagulação/flogulação para remoção do catalisador TiO2 do meio reacional após fotodegradação da carga orgânica /Santos, Jomilson Moraes dos. January 2006 (has links)
Resumo: Esse estudo investigou a cinética de coagulação floculação do TiO2 em suspensão aquosa de baixa força iônica (água destilada)e força iônica média (água de abastecime to público),em função do pH e da adição de sulfato de alumínio. A coagulação floculação do TiO2 ocorre quando o pH é ajustado próximo ao pH do potencial isoelétrico, pela compressão da camada de difusão ou pela adsorção hidrólise com íons Al 3+ . Em suspensões de TiO2 com baixa força iônica,a coagulação ocorre a um determinado pH (4,0 e 7,0), uma vez que ele depende basicamente da superfície do óxido. Com adição de um coadjuvante de sedimentação (por ex. sulfato de alumínio), a qual a força iônica é alta,a coagulação floculação ocorre muito rápido. O tempo de decantação do material em suspensão foi de 2:00 h, foi comparada a cinética de sedimentação da decantação simples com a realizada em Jar Test sob a influência de agitação rápida (eletrocinético) e lenta (ortocinético) antes de permitir a sedimentação. O melhor desempenho foi em Jar Test,turbidez final de 10 NTU. / Abstract: This study investigated the coagulation-flocculation kinetics of TiO2 in an aqueous Suspension of low-strength ionic solution (distilled water) and a medium strength ionic solution (tap water) as a function of pH and of the addition of aluminum sulfate. Coagulation-flocculation of TiO2 occurs when the pH is adjusted close to the isoelectric potential (iep), by compression of the diffusion layer or by adsorption-hydrolysis with Al 3+ ions. In TiO2 suspensions with low electric strength,coagulation takes place at certain pH (4,0 a d 7,0) since it depends basically on the oxide surface.With the addition of sedimentation aid (e.g.,aluminum sulfate), in which the ionic strength is high, coagulation-flocculation, takes place very fast. The decantation time of the material in suspension was of 2h. The sedimentation kinetic of the simple decantation was compared to that carried out in Jar Test under influence of fast stirring (electrokinetic) and slow stirring (ortokinetic) before sedimentation set up.The best performance was in Jar Test,final turbidez of 10 NTU. / Orientador: Ariovaldo de Oliveira Florentino / Coorientador: José Pedro Serra Valente / Banca: Pedro Magalhães Padilha / Banca: Cassio Luis Fernandes de Oliveira / O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp / Mestre
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Characterisation and Performance of three Kenaf coagulation products under different operating conditionsOkoro, B.U., Sharifi, S., Jesson, M., Bridgeman, John, Moruzzi, R. 10 January 2021 (has links)
Yes / The Sustainable Development Goal (SDG) 6.1, established by the United Nations General Assembly in 2015, targets universal and equitable access to safe and affordable drinking water for all by 2030. An essential factor in achieving this goal is the harnessing of “green” coagulants – naturally occurring, environmentally friendly materials which are effective coagulants for use in water treatment, with good availability in developing countries, inherent renewable properties and ease of biodegradation. In order to gain from these benefits, it is essential to fully understand how such coagulants may best be utilised, particularly concerning their practical application in developing countries. In this study, three different plant-based coagulation products (PCPs), namely Hexane (HxKP), saline (StKP) and crude (CrKP) extracts of Kenaf plant seed (Hibiscus cannabinus, a species of the Hibiscus plant), were applied to high (HTW), medium (MTW) and low (LTW) turbidity water in order to determine their performance and coagulation ability. The ability of the three Kenaf coagulant products (KCPs) to remove hydrophobic fractions of natural organic matter (NOM) was measured. The impact of KCPs on the treated water organic matter content (a known disinfection by-product (DBP) precursor) was examined using known surrogates of natural organic matter (NOM) i.e. the dissolved organic carbon (DOC), ultraviolet absorbance at 254 (UV254) and specific ultraviolet absorbance (SUVA254). Results obtained quantify the implications of using these coagulants during the water disinfection process. A parametric study, measuring the effect of different operating parameters, such as untreated water turbidity, pH, dosages, retention time, and KCP storage time, was completed. Turbidity removal performance for HxKP and StKP was very good with > 90% removal recorded for HTW and MTW, respectively, at pH seven within 2 hours retention time. Images obtained from scanning electron microscopy (SEM) analysis revealed a high likelihood of the coagulation mechanism of KCPs to be adsorption-interparticle bridging brought about by their flake-like structures and surfaces charges. Varying pH had no measurable influence on the coagulation performance of the KCPs. Comparing their efficiency with Moringa Oleifera (MO, a previously researched PCP) and alum showed that HxKP had a negligibly different particle removal as MO. StKP turbidity removal performance was below HxKP by 1% for HTW and LTW and 2% for MTW but performed higher than the CrKP by 5% and 7% in HTW and MTW, respectively. The optimum dosage of HxKP and StKP reduced DBP surrogate values, indicating that its precursor is also minimized, although a slight shift from this optimum dosage showed a significant rise in their concentration thus signifying a potential increase in DBPs during disinfection.
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Prirodni koagulanti iz zrna pasulja (Phaseolus vulgaris) u obradi vode / Natural coagulants from common bean (Phaseolus vulgaris) in water treatmentProdanović Jelena 11 March 2015 (has links)
<p>Cilj ove doktorske disertacije je bio da se ispita mogućnost dobijanja prirodnih<br />koagulanata iz zrna pasulja koji bi se koristili u obradi različitih voda i otpadnih voda. U okviru izvedenih eksperimenata su utvrđeni najbolji uslovi za ekstrakciju prirodnih koagulanata iz pasulja, određen je hemijski sastav sirovih ekstrakata dobijenih na različite načine, proverena je trajnost i određen način čuvanja sirovih ekstrakata i ispitan uticaj različitih parametara na koagulacionu aktivnost sirovih ekstrakata.<br />S obzirom na to da su prirodni koagulanti organskog porekla, oni povećavaju sadržaj organskih materija u tretiranoj vodi, pa su u okviru rada ispitane i upoređene različite metode prečišćavanja sirovog ekstrakta pasulja, a zatim određen uticaj sirovog ekstrakta i prečišćenih koagulanata na sadržaj organskih materija u obrađenoj vodi.<br />Kako bi se ispitala efikasnost prirodnih koagulanata iz zrna pasulja u realnim vodama,<br />oni su bili primenjeni u otpadnim vodama od proizvodnje bioetanola. Pored toga, ispitana je mogućnost njihove primene u kombinaciji sa konvencionalnim koagulantima, i na samom kraju je ispitan sastav pasulja koji preostane nakon ekstrakcije prirodnih koagulanata kako bi se utvrdilo da li je pogodan za korišćenje kao<br />dodatak stočnoj hrani.<br />Dobijeni rezultati su pokazali da se iz zrna pasulja može dobiti ekstrakt visoke koagulacione aktivnosti, koji se dalje može efikasno prečistiti tako da ne povećava sadržaj organskih materija u obrađenoj vodi, već ga naprotiv smanjuje. Takođe, prirodni koagulanti iz pasulja se mogu uspešno primeniti za tretman otpadnih voda od proizvodnje bioetanola, mogu biti pomoćni koagulanti aluminijum-sulfatu, a pasulj nakon ekstrakcije prirodnih koagulanata sa destilovanom vodom se može iskoristiti kao<br />dodatak stočnoj hrani.</p> / <p>The aim of this PhD thesis was to investigate the possibility to obtain natural coagulants from common bean which could be used for different waters and wastewaters treatment. The optimal conditions for extraction of natural coagulants from common bean, the chemical composition of crude extracts obtained in different ways and the influence of various parameters on coagulation activity of crude extracts were determined within the performed experiments. The durability of crude extracts was checked and the way of their storage defined.<br />Considering the fact that natural coagulants are of organic origin, they increase the content of organic matter in treated water. Hence, the different methods of purification of common bean crude extract were investigated and compared, and thereafter the influence of crude extract and purified coagulants on organic matter content in treated water was determined.<br />Natural coagulants obtained from common bean were applied in bioethanol stillages in order to explore their efficiency in real waters. Besides, the possibility of their usage combined with conventional coagulants was investigated. At the end, the composition of common bean that remains after extraction of natural coagulants was determined in order to to prove if it was appropriate as addition to feed.<br />Obtained results showed that extract of high coagulation activity can be obtained from common bean. It can be efficiently purified so as not to increase the organic matter content of the water, but on the contrary, to decrease it. Natural coagulants from common bean can be successfully applied for treatment of wastewaters remained after bioethanol production, they can be used as coagulant aid with alum, and the common bean remained after extraction of natural coagulants with distilled water can be utilized as addition to feed.</p>
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Processamento anaeróbio de vinhaça pré-tratada com biopolímero à base de cálcio / Anaerobic processing of vinasse pre-treated with biopolymer-based calciumRocha, Vinícius Carvalho 04 May 2012 (has links)
O objetivo principal desta pesquisa foi comparar o desempenho de dois reatores anaeróbios híbridos de biomassa imobilizada (RAHBI), em escala de laboratório, no processamento da vinhaça de cana-de-açúcar. Um (reator 1) recebendo vinhaça sem tratamento prévio e outro (reator 2) processando vinhaça previamente submetida à coagulação, utilizando-se de um biopolímero experimental a base de cálcio. Os reatores foram construídos em acrílico, com volume de 1,5 litros cada, provido de sistema de recirculação com razão igual a 3. A operação dos reatores foi dividida em duas etapas: a primeira, com duração de 69 dias, teve seu fim caracterizado por um colapso apresentado pelo reator 2. A segunda fase, com duração de 37 dias, onde se observou outro colapso. O principal parâmetro de controle no monitoramento dos reatores foi a quantificação de matéria orgânica, em termos de Demanda Química de Oxigênio (DQO). Durante a Fase I, o reator 1 apresentou eficiência de remoção média de 82,9 ± 4,4% , e o reator 2 de 72,2 ± 18,1%. A carga orgânica volumétrica (COV) média aplicada para o reator 1, durante esta fase, foi de 5,3 ± 1,3 kg DQO/\'M POT.3\'d, e para o reator 2 foi de 5,3 ± 1,6 kg DQO/\'M POT.3\'d. O colapso ocorrido no reator 2 foi evidenciada pelo decréscimo acentuado da eficiência de remoção, chegando a 33,7%. Durante a Fase II, o reator 1 apresentou eficiência de remoção média de 77,5 ± 9,4% , e o reator 2 de 79,2 ± 9,7%. A carga orgânica volumétrica (COV) média aplicada para o reator 1, durante esta fase, foi de 5,1 ± 2,4 kg DQO/\'M POT.3\'d, e para o reator 2 foi de 5,0 ± 2,3 kg DQO/\'M POT.3\'. Ao final desta fase o reator 1 apresentou eficiência de remoção de 80,9%, e o reator 2 65.8%. Foram analisados, também, alcalinidade e produção de metano (\'CH IND.4\'). Durante todas as fases, a alcalinidade dos dois reatores esteve acima de 1000 mg \'CA\'CO IND.3\'/l, indicando estabilidade, em relação a este parâmetro, dos reatores. A produção de \'CH IND.4\' do reator 1 foi de 0,0507 ± 0,0232 l \'CH IND.4\'/h e 0,0838 ± 0,0326 l \'CH IND.4\'/h nas fases I e II, respectivamente. Para o reator 2, esta produção foi de 0,0307 ± 0,0137 l \'CH IND.4\'/h e 0,0800 ± 0,0297 l \'CH IND.4\'/h, para as fases I e II, respectivamente. Foram feitos ensaios de resistência mecânica dos grânulos, análise de microscopia eletrônica de varredura (MEV), Espectrometria de Energia Dispersiva de Raios-X (EDS) e análise da comunidade microbiana, empregando técnicas de biologia molecular. Os testes de resistência mecânica dos grânulos indicam que os grânulos contidos no inóculo, reatores 1 e 2 possuem resistência à desintegração. As análises de MEV e EDS indicam a presença do elemento cálcio com aproximadamente 22% para o inóculo, 39% para o reator 1 e 50% para o reator 2, na massa dos elementos analisados das amostras de grânulos. As análises de biologia molecular indicaram similaridades entre os reatores 1 e 2 de 66,5 e 58%, para os domínios Bacteria e Archea, respectivamente. Desta forma, supõe-se que esta diferença da biota entre os reatores não estaria contribuindo para a falha conferida no reator 2. / This research aimed at compare the performance of two hybrid anaerobic immobilized biomass (HAIB), in laboratory scale, processing vinasse from sugar cane alcohol destilery. Reactor 1 received vinasse without pre-treatment. Reactor 2 processed coagulated vinasse using a calcium-based biopolymer as coagulant. The two reactors were built in acrylic, with a volume of 1,5 liters each. The recirculation flow rate was 3. The operation of the reactors was divided in two phases: first, lasting 69 days, came to an end characterized by a failure (collapse) presented by the reactor 2. The second phase, lasting 37 days, came to an end characterized by another collapse. The main control parameter in the monitoring of the reactors was the quantification of organic matter in terms of COD. During Phase I, the reactor 1 showed average removal efficiency of 82,9 ± 4,4%, and the reactor 2 72,2 ± 18,1%. The organic loading rate (VOC) average applied to reactor 1, during this phase, was 5,3 ± 1,3 kg DQO/\'M POT.3\'d, and 5,3 ± 1,6 kg DQO/\'M POT.3\'d for the reactor 2. The failure occurred in the reactor 2 was evidenced by the sharp decrease of removal efficiency, reaching 33.7%. During Phase II, the reactor 1 showed average removal efficiency of 77,5 ± 9,4%, and the reactor 2 79,2 ± 9,7%. The average VOC applied to reactor 1, during this phase, was 5,1 ± 2,4 kg DQO/\'M POT.3\'d, and 5,0 ± 2,3 kg DQO/\'M POT.3\'d for reactor 2. At the end of this phase, the reactor 1 showed a removal efficiency of 80.9%, and the reactor 2 65.8%. Has also been analyzed, alkalinity and methane (\'CH IND.4\'). During all the phases, the alkalinity of both reactors was above 1000 mg \'CA\'CO IND.3\'/l, indicating stability in the reactors. The production of \'CH IND.4\' was 0.0507 ± 0.0232 l \'CH IND.4\'/h and 0.0326 ± 0.0838 l \'CH IND.4\'/h in phases I and II, respectively. For the reactor 2, the production of \'CH IND.4\' was 0,0307 ± 0,0137 l \'CH IND.4\'/h e 0,0800 ± 0,0297 l \'CH IND.4\'/h for the phases I and II, respectively. Assays were performed in mechanical granules strength, analysis of scanning electron microscopy (SEM), Energy Dispersive Spectroscopy X-ray (EDS) and analysis of the microbial community, using molecular biology techniques. The tests of mechanical of granules strength indicate that the granules contained in the inoculum, reactors 1 and 2 are resistant to disintegration. The SEM and EDS analysis indicated the presence of calcium element with approximately 22% inoculum, 39% for reactor 1 and 50% for reactor 2, in the mass of the elements analyzed samples of granules. The microbial community analyzes indicated molecular similarity between the first and second reactor of 66.5 and 58% for Bacteria and Archea domain, respectively. Thus, it is assumed that the difference between the biota of the reactors would not be contributing to the failure given in the reactor 2.
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Physico-Chemical Processes for Oil Sands Process-Affected Water TreatmentPourrezaei,Parastoo Unknown Date
No description available.
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Tratamento de lixiviado de aterros urbanos utilizando o processo foto-fenton combinado à coagulação/floculaçãoLEITE, Mirella de Andrade Loureiro 09 September 2016 (has links)
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Previous issue date: 2016-09-09 / FACEPE / A presente pesquisa foi motivada pelo desafio em propor um tratamento, em escala laboratorial,
para degradar eficientemente os poluentes dos lixiviados provenientes do Aterro Sanitário de
Altinho – PE, localizado no Agreste do Estado e em funcionamento e Aterro Controlado da
Muribeca – PE, localizado na Região Metropolitana do Recife e fechado desde 2009. Assim,
baseado na característica de alta carga orgânica, porém baixa biodegradabilidade dos lixiviados,
foi realizado um tratamento físico-químico com aplicação dos processos de
coagulação/floculação (CF) e oxidativos avançados do tipo foto-Fenton. Inicialmente, foi feito
um tratamento preliminar dos lixiviados por meio de um planejamento fatorial 24, tendo como
variáveis independentes: massa do coagulante hidróxido de cálcio, tempo e velocidade de
rotação de floculação e tempo de sedimentação. Em seguida, foi aplicado o processo de fotoFenton,
sob as mesmas condições, ao sobrenadante proveniente das amostras pré-tratadas por
CF e diretamente às amostras brutas. Os resultados mostraram remoções de 89,6% e 83,4% de
DQO para a amostra pré-tratada por CF e bruta de Altinho, respectivamente; e remoções de
91,5% e 85,2% de DQO para a amostra pré-tratada por CF e amostra bruta da Muribeca,
respectivamente. Comparando esses resultados, decidiu-se pela não realização de um
tratamento preliminar visto que o percentual de remoção entre as amostras pré-tratadas e brutas
foram relativamente próximos, evitando assim o gasto extra de energia, materiais e tempo. Um
planejamento fatorial 33 foi realizado para o tratamento por foto-Fenton para cada amostra de
lixiviado dos aterros, variando-se concentração de H2O2, proporção de FeSO4.7H2O:H2O2 e pH,
em um tempo reacional de 240 minutos sob radiação solar. Foram obtidos resultados de
percentuais de remoções nas faixas de 52,5% a 87% de DQO, 43,5 a 77% de carbono orgânico
total (COT) e 39 a 74% de substâncias húmicas (SH) para o lixiviado de Altinho; e 53 a 91%
de DQO, 38,5 a 77% de COT e 30 a 64% de SH para o lixiviado da Muribeca. O estudo
estatístico de correlação entre pares dessas variáveis mostrou que essas possuem correlação de
moderada a altamente forte. Os dados experimentais se ajustaram a um modelo cinético de
primeira ordem, alcançando-se 70% de degradação do COT dos dois lixiviados em 30 minutos
de reação. Obteve-se a constante cinética (k) igual a 0,0408 min-1 e coeficiente de regressão
linear (R2) igual a 0,9862 para o lixiviado de Altinho e k = 0,0373 min-1 e R2 = 0,9727 para
Muribeca. A caracterização do lixiviado de Altinho e da Muribeca tratados, em suas condições
ótimas, indicou um aumento da biodegradabilidade e uma remoção eficiente da carga orgânica,
cor e turbidez. Os lixiviados tratados com diluição 1:10 não apresentaram toxicidade. / This research was motivated by the challenge to propose a treatment in laboratory scale to
efficiently degrade pollutants of leachate from the landfill of Altinho - PE, located in the arid
zone of the state and in operation, and landfill of Muribeca - PE, located in Metropolitan Region
of Recife and closed since 2009. Thus, based on the high organic loading characteristic but low
biodegradability of the leachates, a physical-chemical treatment with application of
coagulation/flocculation (CF) and advanced oxidative (photo-Fenton) processes were made.
Initially, a preliminary treatment of the leachate was done by an experimental design 24 using
as independents variables: mass of the calcium hydroxide coagulant, flocculation time,
flocculation rotation speed and settling time. Then, the photo-Fenton process was applied, under
the same conditions, to the supernatant from the pretreated samples and directly to the raw
samples. The results showed 89.6% and 83.4% COD removal for the pretreated sample by CF
and raw sample from Altinho, respectively; and 91.5% and 85.2% COD removal for the
pretreated sample by CF and raw sample from Muribeca, respectively. Comparing these results,
it was decide not to do a pretreatment since the removal percentage between pretreated and raw
samples were relatively close, avoiding the extra expense of energy, materials and time. A 33
factorial design was done for the photo-Fenton treatment to each landfills leachate sample,
ranging the concentration of H2O2, the proportion of FeSO4.7H2O:H2O2 and pH, at a reaction
time of 240 minutes under solar radiation. Percentages of removal results were obtained in the
ranges of 52.5% to 87% of COD, 43.5 to 77% of TOC and 39 to 74% of humic substances (HS)
to the Altinho’s leachate; and 53 to 91% of COD, 38.5 to 77% of TOC and 30 to 64% of HS to
the Muribeca’s leachate. The statistical correlation study between pairs of these variables
showed that it has a moderate to highly strong correlation. The experimental data fitted to a first
order kinetic model, achieving 70% of TOC degradation for the leachate samples at 30 minutes
of reaction. The rate constant (k) was 0.0408 min-1 and the linear regression coefficient (R2)
was 0.9862 for Altinho´s leachate and k = 0.0373 min-1 and R2 = 0.9727 for Muribeca’s
leachate. The characterization of Altinho and Muribeca treated leachate in its optimal condition,
indicated an increase in biodegradability and efficient removal of organic matter, color and
turbidity. The both treated leachate samples with dilution 1:10 showed no toxicity.
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Processamento anaeróbio de vinhaça pré-tratada com biopolímero à base de cálcio / Anaerobic processing of vinasse pre-treated with biopolymer-based calciumVinícius Carvalho Rocha 04 May 2012 (has links)
O objetivo principal desta pesquisa foi comparar o desempenho de dois reatores anaeróbios híbridos de biomassa imobilizada (RAHBI), em escala de laboratório, no processamento da vinhaça de cana-de-açúcar. Um (reator 1) recebendo vinhaça sem tratamento prévio e outro (reator 2) processando vinhaça previamente submetida à coagulação, utilizando-se de um biopolímero experimental a base de cálcio. Os reatores foram construídos em acrílico, com volume de 1,5 litros cada, provido de sistema de recirculação com razão igual a 3. A operação dos reatores foi dividida em duas etapas: a primeira, com duração de 69 dias, teve seu fim caracterizado por um colapso apresentado pelo reator 2. A segunda fase, com duração de 37 dias, onde se observou outro colapso. O principal parâmetro de controle no monitoramento dos reatores foi a quantificação de matéria orgânica, em termos de Demanda Química de Oxigênio (DQO). Durante a Fase I, o reator 1 apresentou eficiência de remoção média de 82,9 ± 4,4% , e o reator 2 de 72,2 ± 18,1%. A carga orgânica volumétrica (COV) média aplicada para o reator 1, durante esta fase, foi de 5,3 ± 1,3 kg DQO/\'M POT.3\'d, e para o reator 2 foi de 5,3 ± 1,6 kg DQO/\'M POT.3\'d. O colapso ocorrido no reator 2 foi evidenciada pelo decréscimo acentuado da eficiência de remoção, chegando a 33,7%. Durante a Fase II, o reator 1 apresentou eficiência de remoção média de 77,5 ± 9,4% , e o reator 2 de 79,2 ± 9,7%. A carga orgânica volumétrica (COV) média aplicada para o reator 1, durante esta fase, foi de 5,1 ± 2,4 kg DQO/\'M POT.3\'d, e para o reator 2 foi de 5,0 ± 2,3 kg DQO/\'M POT.3\'. Ao final desta fase o reator 1 apresentou eficiência de remoção de 80,9%, e o reator 2 65.8%. Foram analisados, também, alcalinidade e produção de metano (\'CH IND.4\'). Durante todas as fases, a alcalinidade dos dois reatores esteve acima de 1000 mg \'CA\'CO IND.3\'/l, indicando estabilidade, em relação a este parâmetro, dos reatores. A produção de \'CH IND.4\' do reator 1 foi de 0,0507 ± 0,0232 l \'CH IND.4\'/h e 0,0838 ± 0,0326 l \'CH IND.4\'/h nas fases I e II, respectivamente. Para o reator 2, esta produção foi de 0,0307 ± 0,0137 l \'CH IND.4\'/h e 0,0800 ± 0,0297 l \'CH IND.4\'/h, para as fases I e II, respectivamente. Foram feitos ensaios de resistência mecânica dos grânulos, análise de microscopia eletrônica de varredura (MEV), Espectrometria de Energia Dispersiva de Raios-X (EDS) e análise da comunidade microbiana, empregando técnicas de biologia molecular. Os testes de resistência mecânica dos grânulos indicam que os grânulos contidos no inóculo, reatores 1 e 2 possuem resistência à desintegração. As análises de MEV e EDS indicam a presença do elemento cálcio com aproximadamente 22% para o inóculo, 39% para o reator 1 e 50% para o reator 2, na massa dos elementos analisados das amostras de grânulos. As análises de biologia molecular indicaram similaridades entre os reatores 1 e 2 de 66,5 e 58%, para os domínios Bacteria e Archea, respectivamente. Desta forma, supõe-se que esta diferença da biota entre os reatores não estaria contribuindo para a falha conferida no reator 2. / This research aimed at compare the performance of two hybrid anaerobic immobilized biomass (HAIB), in laboratory scale, processing vinasse from sugar cane alcohol destilery. Reactor 1 received vinasse without pre-treatment. Reactor 2 processed coagulated vinasse using a calcium-based biopolymer as coagulant. The two reactors were built in acrylic, with a volume of 1,5 liters each. The recirculation flow rate was 3. The operation of the reactors was divided in two phases: first, lasting 69 days, came to an end characterized by a failure (collapse) presented by the reactor 2. The second phase, lasting 37 days, came to an end characterized by another collapse. The main control parameter in the monitoring of the reactors was the quantification of organic matter in terms of COD. During Phase I, the reactor 1 showed average removal efficiency of 82,9 ± 4,4%, and the reactor 2 72,2 ± 18,1%. The organic loading rate (VOC) average applied to reactor 1, during this phase, was 5,3 ± 1,3 kg DQO/\'M POT.3\'d, and 5,3 ± 1,6 kg DQO/\'M POT.3\'d for the reactor 2. The failure occurred in the reactor 2 was evidenced by the sharp decrease of removal efficiency, reaching 33.7%. During Phase II, the reactor 1 showed average removal efficiency of 77,5 ± 9,4%, and the reactor 2 79,2 ± 9,7%. The average VOC applied to reactor 1, during this phase, was 5,1 ± 2,4 kg DQO/\'M POT.3\'d, and 5,0 ± 2,3 kg DQO/\'M POT.3\'d for reactor 2. At the end of this phase, the reactor 1 showed a removal efficiency of 80.9%, and the reactor 2 65.8%. Has also been analyzed, alkalinity and methane (\'CH IND.4\'). During all the phases, the alkalinity of both reactors was above 1000 mg \'CA\'CO IND.3\'/l, indicating stability in the reactors. The production of \'CH IND.4\' was 0.0507 ± 0.0232 l \'CH IND.4\'/h and 0.0326 ± 0.0838 l \'CH IND.4\'/h in phases I and II, respectively. For the reactor 2, the production of \'CH IND.4\' was 0,0307 ± 0,0137 l \'CH IND.4\'/h e 0,0800 ± 0,0297 l \'CH IND.4\'/h for the phases I and II, respectively. Assays were performed in mechanical granules strength, analysis of scanning electron microscopy (SEM), Energy Dispersive Spectroscopy X-ray (EDS) and analysis of the microbial community, using molecular biology techniques. The tests of mechanical of granules strength indicate that the granules contained in the inoculum, reactors 1 and 2 are resistant to disintegration. The SEM and EDS analysis indicated the presence of calcium element with approximately 22% inoculum, 39% for reactor 1 and 50% for reactor 2, in the mass of the elements analyzed samples of granules. The microbial community analyzes indicated molecular similarity between the first and second reactor of 66.5 and 58% for Bacteria and Archea domain, respectively. Thus, it is assumed that the difference between the biota of the reactors would not be contributing to the failure given in the reactor 2.
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Improved Membrane Pretreatment by FloatationXu, Bingjie January 2015 (has links)
Coagulation/flocculation/sedimentation is a common pretreatment process prior to microfiltration (MF) or ultrafiltration (UF) to alleviate membrane fouling, however there has been limited research on floatation as the pretreatment separation process. The main objective of this study is to compare sedimentation with floatation as part of the pretreatment for ultrafiltration of Ottawa River water (ORW) with relatively high natural organic matter (NOM) content. Water samples pretreated at two full-scale plants were subjected to multiple-day UF membrane fouling tests (constant flux with backwash and chemical cleaning) using an automated bench-scale UF hollow fiber membrane system.
For all the experiments, the transmembrane pressure (TMP) increased sharply during the beginning of the operation (~10 h), which indicated the adsorption was significant. In the later cycles, the TMP showed a more linear constant increase, which indicated the built up of the cake layers.
The total fouling index (TFI), hydraulically irreversible fouling index (HIFI) and chemical irreversible fouling index (CIFI) for floated water were much smaller than those of settled waters during both summer and winter testing. Thus, for this type of water coagulation/floatation pretreatment was superior process compared to coagulation/sedimentation, the decreased fouling appears to be linked to greater hydrophobic NOM removal by the coagulation/floatation. For all the tests, HIFI/TFIs were less than 0.1, which is to mean most of the fouling was reversible by hydraulic backwashing.Large fluctuation of backwash efficiencies with time were found for all the tested waters.
Enhanced chemical backwash with 100 ppm chlorine and chemical clean with 0.1N NaOH & 200 ppm chlorine were found to be very effective at reducing fouling for pretreated ORW. As expected longer filtration cycles resulted in greater fouling but with a slightly greater degree of hydraulically reversible fouling.
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