High rate sulfate reduction at pH 6 in a pH-auxostat submerged membrane bioreactor fed with formate.
Many industrial waste and process waters contain high concentrations of sulfate, which can be removed by sulfate-reducing bacteria (SRB). This paper reports on mesophilic (30 degrees C) sulfate reduction at pH 6 with formate as electron donor in a membrane bioreactor with a pH-auxostat dosing system. A mixed microbial community from full-scale industrial wastewater treatment bioreactors operated at pH 7 was used as inoculum. The pH-auxostat enabled the bacteria to convert sulfate at a volumetric activity of 302 mmol sulfate reduced per liter per day and a specific activity of 110 mmol sulfate reduced per gram volatile suspended solids per day. Biomass grew in 15 days from 0.2 to 4 g volatile suspended solids per liter. This study shows that it is possible to reduce sulfate at pH 6 with formate as electron donor at a high volumetric and specific activity with inocula from full-scale industrial wastewater treatment bioreactors operated at neutral pH. The combination of a membrane bioreactor and a pH-auxostat is a useful research tool to study processes with unknown growth rates at maximum activities.
Bijmans
Martijn F M
MF
Sub Department of Environmental Technology, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, The Netherlands. Martijn.Bijmans@wur.nl
Peeters
Tom W T
TW
Lens
Piet N L
PN
Buisman
Cees J N
CJ
D018533:Biomass; D019149:Bioreactors; D003470:Culture Media; D004583:Electrons; D005561:Formates / Q000378:metabolism*; D005740:Gases; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D010084:Oxidation-Reduction; D010316:Particle Size; D012722:Sewage; D013431:Sulfates / Q000378:metabolism*; D013816:Thermodynamics
D003470:Culture Media; D005561:Formates; D005740:Gases; D008567:Membranes, Artificial; D012722:Sewage; D013431:Sulfates