title: A novel full recycling process through two-stage anaerobic treatment of distillery wastewater for bioethanol production from cassava.
abstract: In the present study, a novel full recycling process for bioethanol production was investigated, where three mathematical models were established to simulate the accumulation of major soluble inhibitory substances, including organic compounds, total ions, volatile fatty acids (VFAs) and colorants. These inhibitory substances in the reused water reached a relative steady state after 3-7 batches of anaerobic treatment and recycling process, which coincided with the results of mathematical models. There were no negative effects of these inhibitory substances on ethanol fermentation and the final ethanol yield, fermentation time, starch utilization ratio were very close to that of the conventional process using tap water. However, approximately 7.54% (w/w) of water was lost during each circulation, which was replenished in subsequent circulations, to assure consistent fermentation broth volume. This novel process was confirmed to have a stable operation over 13 recycles. It is concluded the stable states of the inhibitory substances in the reused water can assure this recycling process will run successfully.
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Lihu Road 1800, Wuxi 214122, PR China.
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Lu
authors.forename: Lei
authors.initials: L
authors.lastname: Tang
authors.forename: Zhong-Gui
authors.initials: ZG
authors.lastname: Mao
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Zhang
authors.forename: Hong-Jian
authors.initials: HJ
authors.lastname: Zhang
authors.forename: Fu-Bao
authors.initials: FB
authors.lastname: Sun
mesh_terms: D000434:Alcoholic Beverages; D000693:Anaerobiosis; D056804:Biofuels / Q000032:analysis*; D003247:Conservation of Natural Resources; D003470:Culture Media; D000431:Ethanol / Q000737:chemistry*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D007221:Industry; D002365:Manihot / Q000737:chemistry*; D015233:Models, Statistical; D010100:Oxygen / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism; D014867:Water / Q000032:analysis*
chemical_list: D056804:Biofuels; D003470:Culture Media; D007220:Industrial Waste; D014867:Water; D000431:Ethanol; D010100:Oxygen