title: Semi-continuous anaerobic co-digestion of sugar beet byproduct and pig manure: Effect of the organic loading rate (OLR) on process performance.
abstract: Anaerobic co-digestion of dried pellet of exhausted sugar beet cossettes (ESBC-DP) with pig manure (PM) was investigated in a semi-continuous stirred tank reactor (SSTR) under mesophilic conditions. Seven hydraulic retention times (HRT) from 20 to 5 days were tested with the aim to evaluate the methane productivities and volatile solids (VS) removal. The corresponding organic loading rates (OLR) ranged from 4.2 to 12.8 gVS/L(reactor) d. The findings revealed that highest system efficiency was achieved at an OLR of 11.2 gVS/L(reactor) d (6 days-HRT) with a methane production rate (MPR) and volatile solids (VS) reduction of 2.91 LCH4/L(reactor) d and 57.5%, respectively. The HRT of 5 days was found critical for the studied process, which leads to volatile fatty acids (VFA) accumulation and sharp drop in pH. However, the increase of HRT permits the recovery of system.
authors.affiliation: Department of Chemical Engineering and Food Technology, Faculty of Sciences, Agrifood Campus of International Excellence (CeiA3), University of Cádiz, 11510 Puerto Real, Cadiz, Spain. Electronic address: kaoutar.aboudi@uca.es.
authors.forename: Kaoutar
authors.initials: K
authors.lastname: Aboudi
authors.affiliation: Department of Chemical Engineering and Food Technology, Faculty of Sciences, Agrifood Campus of International Excellence (CeiA3), University of Cádiz, 11510 Puerto Real, Cadiz, Spain.
authors.forename: Carlos José
authors.initials: CJ
authors.lastname: Álvarez-Gallego
authors.affiliation: Department of Chemical Engineering and Food Technology, Faculty of Sciences, Agrifood Campus of International Excellence (CeiA3), University of Cádiz, 11510 Puerto Real, Cadiz, Spain.
authors.forename: Luis Isidoro
authors.initials: LI
authors.lastname: Romero-García
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D027461:Beta vulgaris / Q000737:chemistry*; D056804:Biofuels / Q000032:analysis; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000032:analysis; D005232:Fatty Acids, Volatile / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008372:Manure / Q000032:analysis*; D008697:Methane / Q000378:metabolism; D009930:Organic Chemicals / Q000032:analysis*; D034421:Sus scrofa; D014835:Volatilization
chemical_list: D056804:Biofuels; D005232:Fatty Acids, Volatile; D008372:Manure; D009930:Organic Chemicals; D002244:Carbon; D008697:Methane
keywords: Co-digestion; Hydraulic retention time; Methane production; Organic loading rate; Semi-continuous tank reactor