title: Biogas production by encased bacteria in synthetic membranes: protective effects in toxic media and high loading rates.
abstract: A bioreactor including encased digesting bacteria for biogas production was developed, and its performance in toxic media and under high organic loading rates (OLRs) was examined and compared with traditional digestion reactors. The bacteria (3 g) were encased and sealed in 3 x 6 cm2 PVDF (polyvinylidene fluoride) membranes with a pore size of 0.1 microm, and then several sachets were placed in the reactors. They were then examined in toxic medium containing up to 3% limonene as a model inhibitor in batch reactors, and OLRs of up to 20 g COD/L.day in semi-continuous digestions. The free and encased cells with an identical total bacterial concentration of 9 g in a medium containing 2% limonene produced at most 6.56 and 23.06 mL biogas per day, respectively. In addition, the digestion with free cells completely failed at an OLR of 7.5 gCOD/L.day, while the encased cells were still fully active with a loading of 15 g COD/L x day.
authors.affiliation: School of Engineering, University of Borås, Borås, Sweden.
authors.forename: Supansa
authors.initials: S
authors.lastname: Youngsukkasem
authors.affiliation: School of Engineering, University of Borås, Borås, Sweden.
authors.forename: Julius
authors.initials: J
authors.lastname: Akinbomi
authors.affiliation: School of Environment, Resources and Development, Asian Institute of Technology, Pathumthani, Thailand.
authors.forename: Sudip K
authors.initials: SK
authors.lastname: Rakshit
authors.affiliation: School of Engineering, University of Borås, Borås, Sweden.
authors.forename: Mohammad J
authors.initials: MJ
authors.lastname: Taherzadeh
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000737:chemistry / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D056804:Biofuels; D019149:Bioreactors / Q000382:microbiology*; D018914:Cells, Immobilized / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D003470:Culture Media; D053138:Cyclohexenes / Q000737:chemistry / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000737:chemistry / Q000378:metabolism; D000077222:Limonene; D008567:Membranes, Artificial; D011145:Polyvinyls / Q000737:chemistry*; D012722:Sewage / Q000382:microbiology; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism; D005465:Fluorocarbon Polymers
chemical_list: D056804:Biofuels; D003470:Culture Media; D053138:Cyclohexenes; D005232:Fatty Acids, Volatile; D000077222:Limonene; D008567:Membranes, Artificial; D011145:Polyvinyls; D012722:Sewage; D013729:Terpenes; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers