AVALIAÇÃO DA INFLUÊNCIA DO MATERIAL SUPORTE E CARACTERIZAÇÃO DA DIVERSIDADE MICROBIANA DE REATORES ANAERÓBIOS PARA O TRATAMENTO DE EFLUENTE DE ABATEDOURO

Abstract

The effluent generated in abattoirs has a high concentration of organic matter and need treatment before being discarded in the water bodies. Anaerobic biological filters are considered a good technique for the treatment of industrial effluents; however, choosing the correct support media is extremely important to ensure the success of the reactor. In the same way, the study of microbial diversity can optimize the performance and the operation of these systems. In this work it was evaluated the efficiency of the treatment of the effluent from slaughterhouse, using three upflow anaerobic biological filters, and it was compared the microbial diversity of these filters. The reactor called A, B and C were built in chloride polivinile and filled with rings of polypropylene, polyurethane foam, or pieces of clay brick, respectively. These reactors were operated at room temperature and the used Hydraulic Retention Times of (HRTs) were of 30, 20, 18, 14, 10, 8, 6, 5, 4, 3, 2, 1.5 and 1 day. To monitor the efficiency of the process, the pH, alkalinity, acidity, Chemistry Oxygen Demand (COD), and total solids content of volatile solids, nitrogen and phosphorus substrate and effluents of each reactor were analyzed. The values of pH decreased with the reduction of HRT and the ratio volatile acidity / alkalinity remained below 0.13 during the majority of the analyzed period. In the one day’s HRT, the reactor C was more effective reaching 80.76 of removal. There was a high rate of nitrogen removal probably due to its low concentration in the substrate. High phosphorus removals also occurred: there was a decrease of phosphorus removal when the HRT declines in reactors A and B, the same did not occur in the reactor C. The three reactors behaved similarly regarding to the collecting sites and there was no difference between these sites when COD removal, volatile acidity / alkalinity ratio and pH were analyzed. To evaluate the effect of different media support in the microbial community, the reactors DNA biomass was extracted, quantified and used as template in an amplification reaction of 16S rDNA gene from bacteria and metanogenic. The amplified fragments of approximately 1500 bp were treated with HinfI, RsaI and HaeIII restriction enzymes to obtain the reactors ARDRA (Amplified Ribossomal DNA Restriction Analysis) profiles. The indices of richness, richness modified, Shannon-Weaver diversity index and similarity dendogram, determined from ARDRA, grouped the reactors A and B, and left the reactor C isolated due to its dissimilarity. The Hierarchical Cluster Analysis (HCA) also grouped the reactors that way, however, that group has less than 0.1% of similarity, suggesting a low interference in the reactors media support in microbial communities.