Biomethane enhancement using reduced graphene oxide in anaerobic digestion of municipal solid waste
Hamdi Muratçobanoğlu, Öznur Begüm Gökçek, Fatma Muratçobanoğlu, Ruhullah Ali Mert, Sevgi Demirel
Abstract
The present research investigated the impact of reduced graphene oxide (rGO) addition on the semi-continuous anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) in the range of 0.5–10 gVolatileSolid(VS)/L reactor day organic loading rates (OLR). Adding rGO enhanced the rate and yield of biomethane production, and the maximum biomethane increment rate was obtained as 110% at an OLR of 4.0 gVS/L reactor day. However, after increasing the OLR to 6 gVS/L reactor day, there was a dramatic decrease in biomethane production because of volatile fatty acid (VFA) accumulation. Methanotrix is the predominant archaeal genus at OLRs lower than 6 gVS/L reactor day in reactors (89–97%). An increment in biomethane production was associated with the higher abundance of the Methanothrix genus in the rGO-supported reactor (rG) than in the control reactor (rC).