Assessment of a fixed biomass anaerobic reactor for the treatment of vinasse.

Abstract

The Cane alcohol vinasse assessment on the removal efficiency of a fixed biomass anaerobic reactor (FBAR) was evaluated. Crude vinasse was used to feed the reactor. The FBAR was operated with organic load rate (OLR) of 0.5, 1, 3 and 6 gCOD/L/d. Removal efficiencies of 85, 82, 75 and 66 per cent were observed respectively. The FBA reactor presented an excellent removal of organic matter, however, when more than OLR of 3 gCOD/L/d, an unexpected behavior began, it reduced its capacity. The average biogas production was 1.925, 2.613, 5.653 and 8.290 L for OLR of 0.5, 1, 3 and 6 gCOD/L/d respectively. The methane content in biogas was 56, 79, 89 and 82 per cent, in each OLR tested. Methane production was 1.070 L for an OLR 0.5 gCOD/L/d, 2.070 L on an OLR of 1 gCOD/L/d, 5.046 L with OLR of 3 gCOD/L/d and 6.800 L to OLR of 6 gCOD/L/d. Methane performance was used as monitoring parameter, this parameter gives information of the value between the catabolic activity (methane production) and the anabolic activity (bio-film production). The average YCH4, values were 0.304, 0.302, 0.306 and 0.205 LCH4/gCODremoved, respectively. The thermoplastic support inoculated in the FBA reactor and fed with crude vinasse, acted as a filter, plus getting good results in removal of chemical oxygen demand (COD), but because of the size and height of the filling, the methane evacuation stopped.