Solid anaerobic digestion batch with liquid digestate recirculation and wet anaerobic digestion of organic waste: Comparison of system performances and identification of microbial guilds.
Solid anaerobic digestion batch (SADB) with liquid digestate recirculation and wet anaerobic digestion of organic waste were experimentally investigated. SADB was operated at an organic loading rate (OLR) of 4.55kgVS/m3day, generating about 252NL CH4/kgVS, whereas the wet digester was operated at an OLR of 0.9kgVS/m3day, generating about 320NL CH4/kgVS. The initial total volatile fatty acids concentrations for SADB and wet digestion were about 12,500mg/L and 4500mg/L, respectively. There were higher concentrations of ammonium and COD for the SADB compared to the wet one. The genomic analysis performed by high throughput sequencing returned a number of sequences for each sample ranging from 110,619 to 373,307. More than 93% were assigned to the Bacteria domain. Seven and nine major phyla were sequenced for the SADB and wet digestion, respectively, with Bacteroidetes, Firmicutes and Proteobacteria being the dominant phyla in both digesters. Taxonomic profiles suggested a methanogenic pathway characterized by a relevant syntrophic acetate-oxidizing metabolism mainly in the liquid digestate of the SADB. This result also confirms the benefits of liquid digestate recirculation for improving the efficiency of AD performed with high solids (>30%w/w) content.
LAR Laboratory - Dipartimento di Ingegneria, Via G. Duranti 93, 06125 Perugia, Italy; CIMIS, Via G. Duranti 67, 06125 Perugia, Italy. Electronic address: francesco.dimaria@unipg.it.
Francesco
F
Di Maria
LAR Laboratory - Dipartimento di Ingegneria, Via G. Duranti 93, 06125 Perugia, Italy.
Martino
M
Barratta
LAR Laboratory - Dipartimento di Ingegneria, Via G. Duranti 93, 06125 Perugia, Italy.
Francesco
F
Bianconi
LAR Laboratory - Dipartimento di Ingegneria, Via G. Duranti 93, 06125 Perugia, Italy.
Pisana
P
Placidi
LAR Laboratory - Dipartimento di Ingegneria, Via G. Duranti 93, 06125 Perugia, Italy.
Daniele
D
Passeri
D000693:Anaerobiosis; D001419:Bacteria; D001673:Biodegradation, Environmental; D056804:Biofuels; D019149:Bioreactors / Q000382:microbiology; D005232:Fatty Acids, Volatile / Q000737:chemistry; D008697:Methane / Q000032:analysis / Q000737:chemistry; D017013:Methanobacteriaceae / Q000235:genetics; D019638:Methanomicrobiaceae / Q000235:genetics; D017020:Methanosarcina / Q000235:genetics; D059013:Microbial Consortia; D009930:Organic Chemicals / Q000737:chemistry*; D012037:Refuse Disposal; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods*
D056804:Biofuels; D005232:Fatty Acids, Volatile; D009930:Organic Chemicals; D012722:Sewage; D008697:Methane
High throughput sequencing; Liquid digestate recirculation; Methane; Microbial population; Organic waste; Solid anaerobic digestion batch; Wet anaerobic digestion