Anaerobic co-digestion of activated sludge and fruit and vegetable waste: Evaluation of mixing ratio and impact of hybrid (microwave and hydrogen peroxide) sludge pre- treatment on two-stage digester stability and biogas yield
Document Type
Journal Article
Publication Title
Journal of Water Process Engineering
ISSN
22147144
Volume
37
Publisher
Elsevier
School
School of Engineering
RAS ID
31914
Abstract
© 2020 Elsevier Ltd Co-digestion of mixed waste activated sludge (MWAS) and fruit and vegetable waste (FVW) was studied in a two-stage (thermophilic followed by mesophilic) semi-continuous anaerobic digestion to evaluate anaerobic digester performance and stability. A mixing ratio of 75 % MWAS and 25 % FVW showed a 1.6-fold increase in overall methane yield and achieved 0.38 volatile fatty acids to alkaline buffer capacity ratio (FOS/TAC) compared to mixture of 50 % MWAS and 50 % FVW. Application of hybrid (MW-H2O2) pretreatment in the former mixing ratio increased sludge solubilization by 33 % and consequently enhanced overall methane yield by 2.17-fold. The treated digester showed increased process stability with a FOS/TAC ratio of 0.26 as a consequence of buffer capacity offered by released biopolymers during pre-treatment. The generation of superoxide radicals during anaerobic digestion was studied and found to negatively correlate with sludge bioactivity. Two-stage digestion also minimizes the issue of high acidification due to co-digestion involving FVW.
DOI
10.1016/j.jwpe.2020.101498
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Comments
Ambrose, H. W., Philip, L., Suraishkumar, G. K., Karthikaichamy, A., & Sen, T. K. (2020). Anaerobic co-digestion of activated sludge and fruit and vegetable waste: Evaluation of mixing ratio and impact of hybrid (microwave and hydrogen peroxide) sludge pre-treatment on two-stage digester stability and biogas yield. Journal of Water Process Engineering, 37, article 101498. https://doi.org/10.1016/j.jwpe.2020.101498