Anaerobic Digestion of Sugarcane Vinasse Through a Methanogenic UASB Reactor Followed by a Packed Bed Reactor.

The anaerobic treatment of raw vinasse in a combined system consisting in two methanogenic reactors, up-flow anaerobic sludge blanket (UASB) + anaerobic packed bed reactors (APBR), was evaluated. The organic loading rate (OLR) was varied, and the best condition for the combined system was 12.5 kg COD mday with averages of 0.289 m CH kg COD rfor the UASB reactor and 4.4 kg COD mday with 0.207 m CH kg COD r for APBR. The OLR played a major role in the emission of HS conducting to relatively stable quality of biogas emitted from the APBR, with HS concentrations <10 mg L. The importance of the sulphate to COD ratio was demonstrated as a result of the low biogas quality recorded at the lowest ratio. It was possible to develop a proper anaerobic digestion of raw vinasse through the combined system with COD removal efficiency of 86.7% and higher CH and a lower HS content in biogas.