Variáveis microbiológicas e físico-químicas em biodigestores anaeróbios escala piloto alimentados com dejetos de bovinos leiteiros e suínos

Abstract

In Brazil, the livestock has a prominent role in the economy. The volume of processed raw milk in the third quarter of 2015 was 5.9 billion liters, with emphasis on industrialization in Minas Gerais, ranking the first of the Brazilian states, which processed more than 1.5 million liters. On the other hand the total number of pigs slaughtered in the third quarter of 2015 was 10.18 million head, the state of Minas Gerais stood in 4th position with over 1.2 million heads slaughtered (IBGE, 2015). The quota animals required for this production generates a large volume of potentially polluting wastes to the environment. This work aimed to evaluate the features of the tributaries, effluents and microbial groups of interest in the anaerobic digestion process of dairy cattle and swine manure in digesters operated on a pilot scale. This study was conducted with eight PVC digesters operated continuously 15 days after the initial feeding, with daily supply in winter and summer seasons 2014. The first analysis for the characterization of influent and effluent was carried out in digester input and more four outputs, being made physicochemical and microbiological analyzes during the 60 days of hydraulic retention time. The waste in the two stations were down some desirable physicochemical parameters and increase in others. Regarding the microbiological parameters, a reduction in all microbial groups studied, both stations, the reduction being significant in the summer to the winter. It was found that both cattle manure as pigs showed good results, demonstrated the efficiency of the system, is of great economic and environmental importance of the application of the same in the production units of dairy cattle and swine.