BIOCHEMICAL METHANE POTENTIAL IN THE ANAEROBIC CO-DIGESTION OF PIGMANURE, WITH AGROINDUSTRIAL WASTES, IN BATCH REACTORS

Abstract

The biochemical methane potential (BMP) in the anaerobic co-digestion of pig manure (EP) with Ataulfo mango (MA) wastes and crude glycerin (GC) in batch bioreactors was evaluated in mesophilic conditions. The bioreactors were operated with anaerobic sludge (1-1.5gSTV/g) as inoculum and an organic load of 3-3.5 gCOD/g (30%MA/70%EP and 5%GC/95%EP), a control with 100%EP and a blank with inoculum without substrate. The kinetics for methane production were followed during 40 days obtaining 246 mLCH4/gDQO and 340 mLCH4/gDQO for the 30%MA/70%EP and 5%GC/95%EP treatments, respectively. In contrast, a low methane yield production of 178 mLCH4/gDQO was obtained with 100%EP. The addition of EP and MA wastes and GC favored the process stability, enabling the production of methane gas was carried out without the addition of alkaline substances. Therefore, the mixture of EP with agroindustrial wastes (MA and GC) in anaerobic co-digestion is an alternative to enhance methane production compared with EP anaerobic digestion alone.

Key Words: co-digestion, methane, wastes.