Modelos matemáticos na predição de parâmetros da biodigestão anaeróbia de efluente da produção de suínos

Abstract

The objective was to test mathematical models to estimate the parameters of anaerobic digestion as a function of varying the composition of effluents from pig farms with and without separation of the solid fraction and hydraulic retention times (HRT). For development work semi - continuous digesters supplied with effluent with and without separation of the solid fraction of swine varied composition, manned by 15, 22, 29 and 36 days of retention time were used. Data were tested by regression analysis by step (stepwise) procedure. Potential for biogas production and methane reductions and total, solid volatile solids, chemical oxygen demands were evaluated. Multiple models and the univariate linear regression, showing good predictive ability for all parameters tested were obtained. Parameters evaluated the levels of ST, SV and HRT were the most important because they showed the highest correlations and appear in all prediction equations. The models had found high levels of trust, which classified them as great at predicting production potential and good in predicting reductions in ST and SV, with the best results observed for the multivariate regressions. In univariate linear regression, stands out HRT variable. The models in this study can be used to predict the vestments of the anaerobic digestion of swine wastewater process, showing the variables that interfere in the digestion process.