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Title: Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste

Abstract

Highlights: • Effect of micro-aeration on acidogenesis and hydrolysis of food waste was investigated. • Micro-aeration at 258 L-air/kg TS/d increased the VFAs production 3-fold. • High aeration leads to loss of substrate through microbial biomass and respiration. • Optimum aeration increased methane recovery while high aeration intensity reduced methane yield. - Abstract: Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387 L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35 °C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21–27% and 38–64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27 L CH{sub 4}/g VS{sub added} in the UASB. The performance of LBR-6h withmore » inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO{sub 2} respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258 L-air/kg TS/d is recommended for acidogenic LBR treating food waste.« less

Authors:
 [1];  [2]
  1. Department of Environmental and Low-Carbon Science, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai (China)
  2. Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region (Hong Kong)
Publication Date:
OSTI Identifier:
22304614
Resource Type:
Journal Article
Journal Name:
Waste Management
Additional Journal Information:
Journal Volume: 34; Journal Issue: 2; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0956-053X
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; ACETIC ACID; AERATION; BIOMASS; BUTYRIC ACID; CARBOHYDRATES; CARBON; CARBON DIOXIDE; ENZYMES; FOOD; HYDROLYSIS; LEACHING; MATERIALS RECOVERY; METHANE; OPTIMIZATION; ORGANIC WASTES; SOLIDS

Citation Formats

Xu, Suyun, Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, Selvam, Ammaiyappan, and Wong, Jonathan W.C., E-mail: jwcwong@hkbu.edu.hk. Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste. United States: N. p., 2014. Web. doi:10.1016/J.WASMAN.2013.10.038.
Xu, Suyun, Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, Selvam, Ammaiyappan, & Wong, Jonathan W.C., E-mail: jwcwong@hkbu.edu.hk. Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste. United States. https://doi.org/10.1016/J.WASMAN.2013.10.038
Xu, Suyun, Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, Selvam, Ammaiyappan, and Wong, Jonathan W.C., E-mail: jwcwong@hkbu.edu.hk. 2014. "Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste". United States. https://doi.org/10.1016/J.WASMAN.2013.10.038.
@article{osti_22304614,
title = {Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste},
author = {Xu, Suyun and Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region and Selvam, Ammaiyappan and Wong, Jonathan W.C., E-mail: jwcwong@hkbu.edu.hk},
abstractNote = {Highlights: • Effect of micro-aeration on acidogenesis and hydrolysis of food waste was investigated. • Micro-aeration at 258 L-air/kg TS/d increased the VFAs production 3-fold. • High aeration leads to loss of substrate through microbial biomass and respiration. • Optimum aeration increased methane recovery while high aeration intensity reduced methane yield. - Abstract: Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387 L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35 °C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21–27% and 38–64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27 L CH{sub 4}/g VS{sub added} in the UASB. The performance of LBR-6h with inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO{sub 2} respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258 L-air/kg TS/d is recommended for acidogenic LBR treating food waste.},
doi = {10.1016/J.WASMAN.2013.10.038},
url = {https://www.osti.gov/biblio/22304614}, journal = {Waste Management},
issn = {0956-053X},
number = 2,
volume = 34,
place = {United States},
year = {Sat Feb 15 00:00:00 EST 2014},
month = {Sat Feb 15 00:00:00 EST 2014}
}