Monitoramento de biodigestores alimentados por resíduos e dejetos da agroindústria (abatedouro e queijeira) gerados na região de Pombal - PB.

Abstract

This paper discuss the performance of two anaerobic digesters (batch type) powered by the agroresidues and wastes (wastes from slaughterhouses and cattle dung with and without addition of whey), generated in the Region of Pombal - PB with purpose to produce biogas and biofertilizer. Two anaerobic reactors with a capacity of 220 L were constructed and activated with different proportions of mixtures of biomass and then diluted at 1:1 (mixed biomass / water). The monitoring proceeded along 35 days, the substrates were evaluated at times 0, 7, 14, 21, 28 and 35 days of hydraulic retention through physical chemical parameters, such as temperature, pH, conductivity, total volatile and fixed solids. Besides checking the macronutrients (NPK) for the affluent and effluent of both bioreactors. The biogas production was investigated seeking to infer the efficiency of anaerobic digestion processes. The results showed that during the process of digestion the reactor B (without the whey) performed better, although the values of the tests were not very far from the digester A. Nevertheless they are significant because that last one has alkaline pH (7.96), shows more reductions of total and volatile solids (70%), greater fixation of macronutrients (NPK) in their effluent (biofertilizer) in concentrations of 18.84 g/kg, 15.32 g/kg and 39.06 mg/kg, respectively Nitrogen, Phosphorus and Potassium. Regarding the production of biogas, both bioreactors started its production from the 14th day, and on the 35th day it was recorded 2.4 L and 3.1 L, respectively for the digester A and B. The reactor A showed leaks at some points of connections, but that was repaired immediately. Despite this digester has been slightly more acid over the other due to contain whey in a mixture it was not necessary a supplementation of alkalinity. Finally, it can be inferred that the results were satisfactory, especially those obtained in monitoring the reactor B. Making us understand that the use of these wastes generated by agribusinesses in the region of Pombal - PB, can be worked through biodigestion, targeting two excellent byproducts, biogas and fertilizer, which will contribute not only as proposals for sustainable models, but also as a way to increase the income generated by these activities in the region.