This study evaluated the operational conditions that maximize the production of biogas from the use of digesters. Experimental tests were conducted using termination phase swine wastes, with total solids in collecting 70.6% w/v. The experiments evaluated according to the response surface methodology (RSM), the influence of five factors: temperature, initial concentration of organic matter and influence of inorganic nutrients addition (FeSO4×7H2O, NiSO4×6H2O and MnSO4×4H2O). Better results were obtained for the initial concentration biomass of 395 to 595 g.L-1 and temperatures from 33.5 to 44ºC. Regarding the use of nutrients in the anaerobic digestion process, the results showed that there was significant reduction in hydraulic retention time and increased biogas productivity.
waste; environment; pig production; biodigester