A grande quantidade, alta carga orgânica e toxicidade dos resíduos do processo de curtimento, junto com a crescente importância da geração de energia a partir de fontes renováveis, fazem com que seja necessário estudar formas de biodegradação dos resíduos sólidos produzidos pela indústria coureira e gerar energia a partir desse processo. Os principais resíduos sólidos produzidos pelos curtumes são farelo de couro da etapa de rebaixamento e lodos provenientes das estações de tratamento de efluentes. Esses resíduos, quando contêm o agente curtente, frequentemente sal de cromo, costumam ser dispostos em aterros de resíduos industriais perigosos. O biogás com alto teor de metano é o produto da decomposição, através de digestão anaeróbia, de matéria orgânica e inorgânica. O estudo propõe avaliar a produção de biogás e de metano e a variação de matéria orgânica e inorgânica em ensaios controlados de co-digestão anaeróbia dos dois principais resíduos sólidos da indústria coureira, farelo de couro do rebaixamento da espessura do couro e lodo de estações de tratamento de efluentes. / The large amount, high organic load and toxicity of the tanning waste, besides the growing importance of the generation of energy from renewable sources, make the study of ways of biodegradation of solid waste produced by the tannery industry and generation of energy from this process necessary. The main solid waste produced by tanneries is leather shavings from thickness adjustment step and sludge from wastewater treatment plants. Such residues, when containing the tanning agent, often chromium salt, are often disposed of in hazardous industrial waste landfills. Biogas with high methane content is the product of decomposition, through anaerobic digestion, of organic and inorganic matter. The study proposes to evaluate the production of biogas and methane and the variation of organic and inorganic matter in controlled anaerobic co-digestion tests of the two main solid wastes of the tannery industry, leather shavings from thickness adjustment step and sludge from wastewater treatment plants. This study was realized by monitoring the process, comparing and analyzing the interaction between residues without tanning agent and with the two main tanning agents, chromium salt and vegetable tannins, the analysis of the influence of the heating pre-treatment of the shavings, cost analysis, addition of raw tannery effluent as nutrient supply, analysis of microbial population and addition of different co-substrates. The results showed that the amount of chromium present in the wastes is not inhibitory for the microorganisms and that the high affinity of the chromium in the residues does not allow the chromium to be metabolized by the microorganisms, different from the residues with vegetal tannins and from the stages previous to the tanning, that did not show favorable to the biodegradation process. The process scale-up showed that in larger scales the process occurs more quickly. The addition of microalgae biomass has tripled biogas production, while the addition of tanning effluent has drastically reduced production, however, it is economically feasible as it saves on the treatment and disposal of wastewaters. The characterization of the microbial population showed that the Methanosaetaceae family is the main one responsible for the production of methane.
| Identifer | oai:union.ndltd.org:IBICT/oai:www.lume.ufrgs.br:10183/185805 |
| Date | January 2018 |
| Creators | Agustini, Caroline Borges |
| Contributors | Gutterres, Mariliz, Costa, Marisa da |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, instname:Universidade Federal do Rio Grande do Sul, instacron:UFRGS |
| Rights | info:eu-repo/semantics/openAccess |
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