Produção de hidrogênio e metano a partir de efluentes de suinocultura e manipueira em reatores anaeróbios

Abstract

The agro-industrial effluents, due to its high polluter, requires use of technologies for the treatment and reuse of the effluents, creating a challenge for the producers to fit their process of production to the correct way. The use of anaerobic digestion and biogas generation is a great alternative to this and generates many benefits such as reducing pollution and emission of gas with high energy. In this context, this study evaluated the hydrogen production in an anaerobic fluidized bedsteady reactor, sequenced by an anaerobic fixed bedsteady reactor, which were fed with swine wastewater supplemented with cassava wastewater. Different proportions were used in solution, sequentially at four different phases, increasing swine effluent and gradually decreased the cassava wastewater: phase 1 – 25% swine, 50% water and 25% cassava wastewater (S25A50M25); phase 2 – 50% swine, 25% water and 25% cassava wastewater (S50A25M25); phase 3 – 75% swine, 10% water and 15% cassava wastewater S75A10M15); phase 4 – 85% swine, 0% water and 15% cassava waste water (S85A0M15). Chemical analyzes were performed to monitor the production of biogas. With the results, it was found that it was possible to detect the production of hydrogen and methane from the anaerobic reactors consortium that was proposed. The income of hydrogen production found at the Phases 1, 2, 3 and 4 were respectively 1.13 (28.14%), 0.57 (14.34%), 0.63 (15.70%) and 0.14 (3.61%) explained by the decrease in concentration of carbohydrates, which leads to the production of less hydrogen. The main soluble metabolites were detected and quantified were: acetic acid (32 - 50%), butyric acid (15 – 28%), propionic acid (0 – 42%) and ethanol (0 - 49%). At all phases, there showed acetic acid and butyric acid, the propionic acid had emphasis at the en oh the research, phase that the swine effluent had a high concentration stimulating others fermentative routes, unfavorable to hydrogen production and favorable to methane production. The greatest methane production was obtained at HRT of 24 hours with values in order of 12,11 ± 3,49 mL CH4 / L.h, phase in which the affluent found higher organic matter content available. The higher income was obtained at HRT to 12 hours in order of 1,90 mL CH4/g DQO.