title: The effect of pH on continuous biohydrogen production from swine wastewater supplemented with glucose.
abstract: The effect of pH on hydrogen production from liquid swine manure supplemented with glucose by a mixed culture of fermentative bacteria in an anaerobic sequencing batch reactor was evaluated in this study. At 37 +/- 1 degrees C, five pH values ranging from 4.7 to 5.9 at an increment of 0.3 were tested at a hydraulic retention time (HRT) of 16 h. The results showed that at this HRT, the optimal pH for hydrogen production was 5.0, under which the biogas comprised 33.57 +/- 5.65% of hydrogen with a production rate of 8.88 +/- 2.94 L-H(2)/day and a yield of 1.48 +/- 0.49 L-H(2)/L liquid swine manure. The highest biomass concentration, highest butyric acid to acetic acid ratio, lowest propionic acid concentration, and the best stability were all found at pH 5.0, while the highest CH(4) productivity was found at pH 5.9. For efficient hydrogen production, oxygen content should be controlled under 2%, beyond which an inverse linear relationship (R(2) = 0.986) was observed.
authors.affiliation: University of Minnesota, St. Paul, MN 55108, USA. lixxx644@umn.edu
authors.forename: Yecong
authors.initials: Y
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: Xiao
authors.initials: X
authors.lastname: Wu
authors.forename: Curtis
authors.initials: C
authors.lastname: Miller
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
mesh_terms: D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D056804:Biofuels / Q000032:analysis*; D018533:Biomass; D019149:Bioreactors; D002245:Carbon Dioxide / Q000032:analysis; D000431:Ethanol / Q000032:analysis; D005232:Fatty Acids, Volatile / Q000032:analysis; D005947:Glucose / Q000494:pharmacology*; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008372:Manure; D008697:Methane / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D012995:Solubility / Q000187:drug effects; D034421:Sus scrofa; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D056804:Biofuels; D005232:Fatty Acids, Volatile; D008372:Manure; D002245:Carbon Dioxide; D000431:Ethanol; D006859:Hydrogen; D005947:Glucose; D008697:Methane; D010100:Oxygen