Journal
JOURNAL OF ENVIRONMENTAL MANAGEMENT
Volume 290, Issue -, Pages -Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jenvman.2021.112457
Keywords
Anaerobic co-digestion; Biochar properties; Syntrophic oxidation; VFA mitigation; Biochar-enriched digestate; Food waste
Categories
Funding
- Environment and Conservation Fund, Hong Kong Administrative region [108/2018]
- United Kingdom Biochar Research Centre
Ask authors/readers for more resources
This study demonstrated that the addition of specific biochars with desirable properties can effectively alleviate VFA accumulation, facilitate enhanced methane recovery, improve process stability, and produce digestate rich in nutrients, with the potential to replace agricultural fertilizers.
This work investigated the impact of the addition of different biochar types on mitigation of volatile fatty acid (VFA) accumulation, methane recovery and digestate quality in mesophilic food waste-sludge co-digestion. Four biochars derived from agricultural and sludge residues under different pyrolysis temperatures were compared. Specific biochar properties such as pH, surface area, chemical properties and presence of surface functional groups likely influenced biochar reactions during digestion, thereby resulting in a varying performance of different biochars. Miscanthus straw biochar addition led to the highest specific methane yield of 307 +/- 0.3 mL CH4/g VSadded versus 241.87 +/- 5.9 mL CH4/g VSadded from control with no biochar addition over 30 days of the co-digestion period. Biochar supplementation led to enhanced process stability which likely resulted from improved syntrophic VFA oxidation facilitated by specific biochar properties. Overall, a 21.4% increase in the overall methane production was obtained with biochar addition as compared to control. The resulting digestate quality was also investigated. Biochar-amended digester generated a digestate rich in macro- and micro-nutrients including K, Mg, Ca, Fe making biochar-amended digestate a potential replacement of agricultural lime fertilizer. This work demonstrated that the addition of specific biochars with desirable properties alleviated VFA accumulation and facilitated enhanced methane recovery, thereby providing a means to achieve process stability even under high organic loading conditions in co-digestions. Moreover, the availability of biochar-enriched digestate with superior characteristics than biochar-free digestate adds further merit to this process.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available