title: Biogenic hydrogen conversion of de-oiled jatropha waste via anaerobic sequencing batch reactor operation: process performance, microbial insights, and CO2 reduction efficiency.
abstract: We report the semicontinuous, direct (anaerobic sequencing batch reactor operation) hydrogen fermentation of de-oiled jatropha waste (DJW). The effect of hydraulic retention time (HRT) was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L ∗ d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d) with a DJW concentration of 200 g/L, temperature 55 °C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L ∗ d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30 °C, and pH 7.0. PCR-DGGE analysis revealed that combination of cellulolytic and fermentative bacteria were present in the hydrogen producing ASBR.
authors.affiliation: Department of Environmental Engineering and Science, Feng Chia University, Taichung 40724, Taiwan ; Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingeniería, Unidad Académica Juriquilla, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, QRO 76230, Mexico.
authors.forename: Gopalakrishnan
authors.identifier: 0000-0002-7848-5138
authors.initials: G
authors.lastname: Kumar
authors.affiliation: Department of Environmental Engineering and Science, Feng Chia University, Taichung 40724, Taiwan ; Green Energy Development Center, Feng Chia University, Taichung 40724, Taiwan ; Master's Program of Green Energy Science and Technology, Feng Chia University, Taichung 40724, Taiwan.
authors.forename: Chiu-Yue
authors.initials: CY
authors.lastname: Lin
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D001673:Biodegradation, Environmental; D056804:Biofuels; D019149:Bioreactors; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism*; D031286:Jatropha / Q000378:metabolism* / Q000382:microbiology*; D055432:Metabolomics; D054892:Metagenome; D064307:Microbiota; D008969:Molecular Sequence Data; D012037:Refuse Disposal
chemical_list: D056804:Biofuels; D006859:Hydrogen