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Consultar: Programa de Ps-Graduao em Engenharia Qumica

Incio > Dissertaes e Teses > Engenharias > Engenharia Qumica > Programa de Ps-Graduao em Engenharia Qumica

Ttulo [PT]: Aplicao de um processo de complexao/ultrafiltrao para remoo de poluentes do efluente do branqueamento TCF (totally chlorine free)
Ttulo [EN]: Application of ultrafiltration-complexation process for metals removal from totally clorine-free (tcf) bleaching effluent
Autor(es): Marcelo Fernandes Vieira
Palavras-chave [PT]:

Papel e celulose. Branqueamento. Remoo de poluentes. Processo de complexao/ultrafiltrao. Brasil.
Resumo:
Resumo: Neste trabalho foi investigada a aplicao de um processo de complexao/ultratiltrao na remoo de metais complexados por DTPA (cido Di-etileno Pentactico) a partir do efluente da 2 etapa do branqueamento TCF (total chiorine Free). Este estudo foi realizado em duas etapas: testes preliminares e complementares. Os experimentos preliminares foram realizados em batelada num mdulo de ultrafiltrao com fluxo perpendicular. Foram avaliados os parmetros, tipo de membrana, adio e concentrao do polmero complexante, tempo de contato (entre o polmero e o efluente), e pH A performance das membranas e dos polmeros complexantes foi analisada em termos de porcentagem de remoo de metais e DQO (Demanda Qumica de Oxignio). Os resultados dos testes preliminares mostraram que as melhores remoes foram alcanados com a membrana M5 e o polmero PVA. Apenas deve ser salientado que o polmero PEI no estava disponvel nesta etapa. O tempo de contato influenciou de forma significativa a remoo de metais, principalmente com relao ao Fe. Remoes da ordem de 54% de Fe foram alcanadas para tempos de contato 24 horas, e de 83% para tempos de contato 5 dias, (polmero PEI, pH=4 e membrana M5). Remoes de 49% e 68% foram alcanadas para tempos de contato 24 horas e 5 dias, respectivamente, utilizando-se o PVA, pH=3 e membrana M5. O pH influenciou de maneira significativa na remoo de todos os metais, no qual foram alcanadas remoes de 83% Fe, 46% Mg e 45% Ca na faixa de pH entre 4=5 para o PEI e membrana M5. Para o PVA, trabalhando-se na faixa de pH entre 4-6, as remoes foram de 68%, 39%, 51% para Fe, Mg e Ca. A concentrao dos polmeros complexantes influenciou significativamente a remoo de metais e DQO. Remoes de 59% Fe, 48% Mg, 54% Ca e 56% DOO foram alcanados utilizando-se PVA em concentrao de 12 imol, pH=5. Para o PEI, valores de remoo de 62% Fe, 39% Mg, 45% Ca e 51% DQO foram obtidos trabalhando-se com PEI em concentrao de 12 iimol e pH=5. Aps a determinao dos parmetros avaliados nos testes preliminares foi iniciada a segunda etapa experimental referente aos testes complementares. Os testes complementares foram realizados num mdulo de fluxo tangencial, e foram estudados os parmetros, temperatura, presso e velocidade tangencial. A influncia destes parmetros foi avaliada tanto em relao remoo de metais como fluxo permeado. Os resultados obtidos mostraram que a presso e a temperatura influenciaram de a remoo de metais em ambos sistemas (efluente + PEI e efluente + PVA). J a vanao da velocidade tangencial no apresentou influncia significativa na remoo de metais. r Com respeito ao fluxo permeado, os melhores resultados foram alcanados quando trabalhou-se com presso de 3 bar, velocidade 0,8 m/s e temperatura 50C para ambos sistemas (efluente + PEI e efluente + PVA).

Abstract: The aim of this work was to investigate the reduction of metals chelates of diethylenetriamine pentaacetic acid (DTPA) from totally chlorine-free (TCF) bleachin geffluent by ultrafiltration-complexation process using polyethylenimine (PEI) and polyvinyl alcohol (PVA). This study was accomplished in two stages: preliminary tests and complemental ones. Preliminary experiments were carried out on batch stirred tank. The parameters, membrane type, the polymeric ligants addition and concentration, contact time (between the polymeric and the effluent), and pH were evaluated. The performance of the membranes and of the polymeric ligants were analyzed in terms of metals removal and COD (Chemical Oxygen Demand) percentage. These experiments were performed as a function of: polymeric ligants poly(ethylenimine) (PEI) and poly(vinyl alchool) (PVA) addition and concentration the contact time (effluent with polymeric ligants) and aqueous pH. The performance of the ipolymeric ligands was evaluated by determining metals removal and Chemical Oxygen Demand (COD). The preliminary tests results have showed that the best removals were reached with the M5 membrane and polymeric PVA. It should be pointed out that polymeric PEI was not applied in this stage. The contact time influenced in a significant way the metals removal, mainly with relationship to the Fe. 54% and 83% of Fe removals were reached for 24 hours and 5 days contact time, respectively, under following conditions (polymeric PEI, pH=4 and M5 membrane). On the other hand, removals of 49% and 68% were reached for 24 hours and 5 days contact time, respectively, using PVA, pH=3 and M5 membrane. The pH has significantly influenced metals removal, and using PEI and M5 membrane, pH range of 4-5, removals of 83% Fe, 46% Mg and 45% Ca were reached. For PVA and in the pH range of 4-6, the removals were of 68%, 39%, 51% for Fe, Mg and Ca, respectively. The polymeric ligants concentration has also significantly influenced the COD and metals removal. Removals of 59% Fe, 48% Mg, 54% Ca and 56% COD were reached using 12 mmol PVA concentration and pH=5. Removal values of 62% Fe, 39% Mg, 45% Ca and 51% COD were obtained working with 12 mmol PEI concentration and pH=4.6. After the preliminary tests parameters determination, complemental tests as a second stage were performed. The complemental tests were accomplished in a tangential flow module. The parameters, temperature, pressure and tangential speed were studied. The influence of these parameters on the metals removal as flux permeate was evaluated in details. The obtained results have showed that pressure and temperature have influenced metals removal in both systems (effluent + PEI and effluent + PVA). However, the tangential speed variation didn't present significant influence on metals removal.In general, the process complexation/ultrafiltration was efficient for metals removal from TCF (Totally Chlorine Free) bleaching effluent. The complexation/ultrafiltration process has increased the effluent final quality, compared to the ultrafiltration simple one.With regard to the permeated flow, the best results were reached working with pressure of 3 bar, speed 0,8 m/s and temperature 50oC for both systems (effluent + PEI and effluent + PVA).
Cdigo: vtls000088780
Informaes adicionais:
Idioma: Portugus
Data de Publicao: 1999
Local de Publicao: Maring, PR
Orientador: Prof. Dr. Clia Regina Granhem Tavares
Co-Orientador: Prof. Dr. Rosngela Bergamasco
Instituio: Universidade Estadual de Maring . Departamento de Engenharia Qumica
Nvel: Dissertao (mestrado)/
UEM: Programa de Ps-Graduao em Engenharia Qumica

Responsavel: beth
Categoria: Aplicao
Formato: Documento PDF
Arquivo: MarceloFV.pdf
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Criado: 05-08-2013 18:06
Atualizado: 05-08-2013 18:11
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