Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Digestion of frozen/thawed food waste in the hybrid anaerobic solid-liquid system

Journal Article · · Waste Management
;  [1]
  1. School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)
The hybrid anaerobic solid-liquid (HASL) system, which is a modified two-phase anaerobic digester, is to be used in an industrial scale operation to minimize disposal of food waste at incineration plants in Singapore. The aim of the present research was to evaluate freezing/thawing of food waste as a pre-treatment for its anaerobic digestion in the HASL system. The hydrolytic and fermentation processes in the acidogenic reactor were enhanced when food waste was frozen for 24 h at -20 deg. C and then thawed for 12 h at 25 deg. C (experiment) in comparison with fresh food waste (control). The highest dissolved COD concentrations in the leachate from the acidogenic reactors were 16.9 g/l on day 3 in the control and 18.9 g/l on day 1 in the experiment. The highest VFA concentrations in the leachate from the acidogenic reactors were 11.7 g/l on day 3 in the control and 17.0 g/l on day 1 in the experiment. The same volume of methane was produced during 12 days in the control and 7 days in the experiment. It gave the opportunity to diminish operational time of batch process by 42%. The effect of freezing/thawing of food waste as pre-treatment for its anaerobic digestion in the HASL system was comparable with that of thermal pre-treatment of food waste at 150 deg. C for 1 h. However, estimation of energy required either to heat the suspended food waste to 150 deg. C or to freeze the same quantity of food waste to -20 deg. C showed that freezing pre-treatment consumes about 3 times less energy than thermal pre-treatment.
OSTI ID:
21153986
Journal Information:
Waste Management, Journal Name: Waste Management Journal Issue: 9 Vol. 28; ISSN WAMAE2; ISSN 0956-053X
Country of Publication:
United States
Language:
English

Similar Records

Anaerobic co-digestion of food waste and landfill leachate in single-phase batch reactors
Journal Article · Fri Nov 14 23:00:00 EST 2014 · Waste Management · OSTI ID:22436826

High-rate two-phase process for the anaerobic degradation of cellulose, employing rumen microorganisms for an efficient acidogenesis
Journal Article · Tue Apr 05 00:00:00 EDT 1988 · Biotechnol. Bioeng.; (United States) · OSTI ID:6930066

Anaerobic Co-Digestion of Vegetable and Fruit Market Waste in LBR + CSTR Two-Stage Process for Waste Reduction and Biogas Production
Journal Article · Wed May 15 00:00:00 EDT 2019 · Applied Biochemistry and Biotechnology · OSTI ID:22927760