Obtenção de carvão ativado a partir do resíduo de casca do eucalipto branco
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Data
2021-06
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Souza, Claucia Fernanda Volken De
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O carvão ativado é o material mais utilizado nos processos de adsorção de diferentes substâncias, entre as quais se destacam os de corantes de efluentes industriais. Novas formas de obtenção deste produto tem sido estudadas, como, a partir de resíduos agroindustriais, que são materiais de elevada disponibilidade e custo reduzido. Os resíduos gerados pelo beneficiamento da madeira, como cascas, lascas e serragem, muitas vezes não têm um reaproveitamento adequado, sendo destinados a compostagens, aterros ou até a incineração, gerando um problema ambiental. Visando atender a estas duas demandas, o objetivo deste foi obter um carvão ativado a partir do resíduo de cascas de eucalipto branco como adsorvente para corantes. Os materiais foram submetidos à ativação com ZnCl2 e NaOH, seguido por pirólise a 550oC em atmosfera inerte de N2 e lavagem com água. Foi realizada a caracterização do material por análise elementar de carbono orgânico total (TOC) e Espectroscopia de raios X por dispersão em energia (EDS), análise termogravimétrica (ATG) e microscopia eletrônica de varredura (MEV). Os ensaios de adsorção foram realizados visando avaliar a capacidade de adsorção dos materiais obtidos e compará-los com o carvão ativado comercial, utilizando as isotermas de adsorção para análise. Os resultados indicam que o carvão ativado com NaOH apresentou melhor desempenho que o carvão ativado com ZnCl2, com eficiência de remoção do corante acima de 70% em 6 minutos e acima de 80% após 20 minutos de adsorção, resultados que se igualam aos obtidos para o carvão ativado comercial. Os três carvões analisados obtiveram um melhor ajuste dos dados para o modelo de Langmuir, com R2 igual a 1. Entre os diferentes tipos de ativação, foi obtido um melhor resultado para a ativação com NaOH, verificando também que houve um processo de lavagem ineficaz na amostra produzida com ZnCl2. Estes resultados são satisfatórios para a obtenção de carvão ativado a partir de resíduos agroindustriais, com eficiência na remoção do corante que se assemelha ao carvão ativado comercial, tornando-se uma alternativa viável para produção de adsorventes e diminuição da disposição de resíduos, abrindo caminho para novos estudos de aprimoramento e aplicação neste tema.
Activated carbon is the material most used in the adsorption processes of different substances, among which those of dyes from industrial effluents stand out. New ways of obtaining this product have been studied, such as from agro-industrial residues, which are materials of high availability and low cost. The residues generated by the processing of wood, such as bark, chips and sawdust, are often not properly reused, being destined for composting, landfills or even incineration, generating an environmental problem. Aiming to meet these two demands, the objective of this was to obtain an activated carbon from the residue of white eucalyptus bark as an adsorbent for dyes. The materials were subjected to activation with ZnCl2 and NaOH, followed by pyrolysis at 550oC in an inert atmosphere of N2 and washing with water. The material was characterized by elemental analysis of total organic carbon (TOC) and energy dispersion X-ray spectroscopy (EDS), thermogravimetric analysis (ATG) and scanning electron microscopy (SEM). The adsorption tests were carried out to evaluate the adsorption capacity of the materials obtained and compare them with commercial activated carbon, using the adsorption isotherms for analysis. The results indicate that activated carbon with NaOH performed better than activated carbon with ZnCl2, with dye removal efficiency above 70% in 6 minutes and above 80% after 20 minutes of adsorption, results that are equal to those obtained for commercial activated carbon. The three carbons analyzed had a better fit of the data for the Langmuir model, with R2 equal to 1. Among the different types of activation, a better result was obtained for activation with NaOH, also verifying that there was an ineffective washing process in the sample produced with ZnCl2. These results are satisfactory for obtaining activated carbon from agro-industrial residues, with efficiency in removing the dye that resembles commercial activated carbon, becoming a viable alternative for the production of adsorbents and reduction of waste disposal, opening the way for new studies for improvement and application in this theme.
Activated carbon is the material most used in the adsorption processes of different substances, among which those of dyes from industrial effluents stand out. New ways of obtaining this product have been studied, such as from agro-industrial residues, which are materials of high availability and low cost. The residues generated by the processing of wood, such as bark, chips and sawdust, are often not properly reused, being destined for composting, landfills or even incineration, generating an environmental problem. Aiming to meet these two demands, the objective of this was to obtain an activated carbon from the residue of white eucalyptus bark as an adsorbent for dyes. The materials were subjected to activation with ZnCl2 and NaOH, followed by pyrolysis at 550oC in an inert atmosphere of N2 and washing with water. The material was characterized by elemental analysis of total organic carbon (TOC) and energy dispersion X-ray spectroscopy (EDS), thermogravimetric analysis (ATG) and scanning electron microscopy (SEM). The adsorption tests were carried out to evaluate the adsorption capacity of the materials obtained and compare them with commercial activated carbon, using the adsorption isotherms for analysis. The results indicate that activated carbon with NaOH performed better than activated carbon with ZnCl2, with dye removal efficiency above 70% in 6 minutes and above 80% after 20 minutes of adsorption, results that are equal to those obtained for commercial activated carbon. The three carbons analyzed had a better fit of the data for the Langmuir model, with R2 equal to 1. Among the different types of activation, a better result was obtained for activation with NaOH, also verifying that there was an ineffective washing process in the sample produced with ZnCl2. These results are satisfactory for obtaining activated carbon from agro-industrial residues, with efficiency in removing the dye that resembles commercial activated carbon, becoming a viable alternative for the production of adsorbents and reduction of waste disposal, opening the way for new studies for improvement and application in this theme.
Descrição
Palavras-chave
Carvão ativado; Cascas de eucalipto branco; Adsorção; Azul de metileno; Activated carbon; White eucalyptus bark; Adsorption; Methylene blue
Citação
DUTRA, Danrley Kristyam Rosa. Obtenção de carvão ativado a partir do resíduo de casca do eucalipto branco. 2021. Monografia (Graduação em Química Industrial) – Universidade do Vale do Taquari - Univates, Lajeado, 06 jul. 2021. Disponível em: http://hdl.handle.net/10737/3250.