Effect of hydrogen and carbon dioxide on carboxylic acids patterns in mixed culture fermentation.
This study investigated the carboxylate spectrum from mixed culture fermentation of three organic waste streams after supplying 2 bar hydrogen and carbon dioxide or a mixture of these two gases to the headspace. Under any modified headspace, propionate production was ceased and butyrate, caproate and the total carboxylate concentrations were higher than in the reactors with N(2) headspace (control). Production of one major compound was achieved under hydrogen and carbon dioxide mixed headspace after 4 weeks of incubation. Both the highest acetate concentration (17.4 g COD/l) and the highest fraction (87%) were observed in reactors with mixed hydrogen and carbon dioxide headspace independent of the substrate used. In the control reactor, acetate made up maximum 67% of the total products. For other products, the highest concentration and fraction were seldom observed together. Selective butyrate production reaching a 75% fraction was found under the carbon dioxide headspace on the carbohydrate rich waste.
VITO-Flemish Institute for Technological Research, Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium. doga.arslan@vito.be
D
D
Arslan
K J J
KJ
Steinbusch
L
L
Diels
H
H
De Wever
C J N
CJ
Buisman
H V M
HV
Hamelers
D019342:Acetic Acid / Q000737:chemistry; D000693:Anaerobiosis / Q000187:drug effects; D057919:Biological Oxygen Demand Analysis; D020148:Butyric Acid / Q000737:chemistry; D002245:Carbon Dioxide / Q000494:pharmacology*; D002264:Carboxylic Acids / Q000737:chemistry*; D018929:Cell Culture Techniques / Q000379:methods*; D005285:Fermentation / Q000187:drug effects*; D006859:Hydrogen / Q000494:pharmacology*; D006868:Hydrolysis / Q000187:drug effects; D011422:Propionates / Q000737:chemistry; D013997:Time Factors; D014865:Waste Disposal, Fluid
D002264:Carboxylic Acids; D011422:Propionates; D020148:Butyric Acid; D002245:Carbon Dioxide; D006859:Hydrogen; C029658:propionic acid; D019342:Acetic Acid