N. Perez-Esteban, S. Vinardell, C. Vidal-Antich, S. Peña-Picola, J.M. Chimenos, M. Peces, J. Dosta, S. Astals
http://dx.doi.org/10.1016/j.scitotenv.2021.152498
Science of the Total Environment, 2022, 813, 152498
Quartile Q1, Impact 7.963
Fermentation (not anaerobic digestion) is an emerging biotechnology to transform waste into easily assimilable organic compounds such as volatile fatty acids, lactic acid and alcohols. Co-fermentation, the simultaneous fermentation of two or more waste, is an opportunity for wastewater treatment plants (WWTPs) to increase the yields of sludge mono-fermentation. Most publications have studied waste activated sludge co-fermentation with food waste or agriindustrial waste.
Mixing ratio, pH and temperature are the most studied variables. The highest fermentation yields have been generally achieved in mixtures dominated by the most biodegradable substrate at circumneutral pH and mesophilic conditions. Nonetheless, most experiments have been performed in batch assays which results are driven by the capabilities of the starting microbial community and do not allow evaluating the microbial acclimation that occurs under continuous conditions. Temperature, pH, hydraulic retention time and organic load are variables that can be controlled to optimise the performance of continuous co-fermenters (i.e., favour waste hydrolysis and fermentation and limit the proliferation of methanogens). This review also discusses the integration of co-fermentation with other biotechnologies in WWTPs. Overall, this review presents a comprehensive and critical review of the achievements on co-fermentation research and lays the foundation for future research.
Funding
This work is supported by the Spanish Government (PID2019-111284RB-I00; MINECO/FEDER), a FPI pre-doc fellowship (PRE2020-092325; MINECO), a research grant 2019FI_B 00394 (AGAUR), a APIF 2018–2019 pre-doc fellowship (University of Barcelona and a Ramon y Cajal fellowship (RYC-2017-22372; MINECO).
Research category: Environment and Industrial Processes