DIGESTIÓN ANAEROBIA DE RESIDUALES SÓLIDOS DEL BENEFICIO HÚMEDO DEL CAFÉ

The wet coffee processing generates solid coffee wastes, such as pulp and husk. The organic matter content of these residuals is in the range of 90.5 ± 1.69 % on a dry basis, which explains the high pollutant load they contribute to the environment. The present paper evaluates the biomethane potential and the effect of the organic loading rates (OLR) over the biodegradation of fresh pulp (Pc I), pulp after a period of frozen storage (Pc II), and dry coffee husk (Cs). The assays were developed at mesophilic temperature (37 ± 1oC) under batch and semicontinuous regimen. The fresh coffee pulp had a methane yield of 259.80 ± 15 NmL CH 4 /g VS. Semicontinuous operation demonstrated that a better performance is achieved when the lower OLR was applied (0.2 g VS/L d). It is not recommended to operate at OLR higher than 0.5 g VS/L d.