Oyster shells improve anaerobic dark fermentation performances of food waste: Hydrogen production, acidification performances, and microbial community characteristics

Anaerobic dark fermentation (DF) performances of food waste (FW) were investigated using oyster shells. The different amount oyster shells(6%-12%(w/w)) were added to the DF system of FW. The result showed that the H2 production rate and cumulative H2 production improved after addition oyster shells. The highest H2 production rate and cumulative H2 production of 8% oyster shells addition group were 8.4 mL/(gVS.h) and 88.2 mL/gVS, which were 11.7%-30.6% and 17.4%-52.9% higher than those of the other test groups. TVFAs production, especially acetic and butyric acids improved after addition oyster shells. The highest TVFAs production was 19291.4 mg/L for 8% oyster shells added group, which was 90.24% higher than that of the unadded group. For 8% oyster shells added group, Lactobacillales, Gallicola, and Bacteroides were the dominant species at genus levels. Thus, the addition of an appropriate amount oyster shells could improve H2 production rate, cumulative H2 production, promote buffering capacity, enhance TVFAs production.

Automated summary

The study found that adding an appropriate amount of oyster shells can improve H2 production rate, cumulative H2 production, promote buffering capacity, and enhance TVFAs production.