title: Establishment and assessment of an integrated citric acid-methane production process.
abstract: To solve the problem of extraction wastewater in citric acid industrial production, an improved integrated citric acid-methane production process was established in this study. Extraction wastewater was treated by anaerobic digestion and then the anaerobic digestion effluent (ADE) was stripped by air to remove ammonia. Followed by solid-liquid separation to remove metal ion precipitation, the supernatant was recycled for the next batch of citric acid fermentation, thus eliminating wastewater discharge and reducing water consumption. 130U/g glucoamylase was added to medium after inoculation and the recycling process performed for 10 batches. Fermentation time decreased by 20% in recycling and the average citric acid production (2nd-10th) was 145.9±3.4g/L, only 2.5% lower than that with tap water (149.6g/L). The average methane production was 292.3±25.1mL/g CODremoved and stable in operation. Excessive Na(+) concentration in ADE was confirmed to be the major challenge for the proposed process.
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
authors.forename: Yang-Qiu
authors.initials: YQ
authors.lastname: Chen
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
authors.forename: Hong-Jian
authors.initials: HJ
authors.lastname: Zhang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
authors.forename: Jia-Wei
authors.initials: JW
authors.lastname: Bao
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Tang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Zhang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
authors.forename: Xu-Sheng
authors.initials: XS
authors.lastname: Chen
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China. Electronic address: maozg@jiangnan.edu.cn.
authors.forename: Zhong-Gui
authors.initials: ZG
authors.lastname: Mao
mesh_terms: D000641:Ammonia / Q000302:isolation & purification; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D019343:Citric Acid / Q000378:metabolism*; D005285:Fermentation; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry; D002365:Manihot / Q000737:chemistry; D008670:Metals / Q000302:isolation & purification; D008697:Methane / Q000096:biosynthesis*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D000641:Ammonia; D019343:Citric Acid; D005087:Glucan 1,4-alpha-Glucosidase; D008670:Metals; D008697:Methane; D062065:Wastewater
keywords: Air stripping; Anaerobic digestion; Citric acid; Glucoamylase; Sodium