12 / 2023-04-25 13:12:03

Improvement of methanogenesis performance from anaerobic digestion of food waste by using nanobubble water and gradually increasing salinity to domesticate inoculum: Adaptability and inoculation ratio

Anaerobic digestion,Food waste,Inoculation ratio,Air nanobubble water,Salinity,Salinity-adaptable inoculum

Salinity has frequently inhibited methane production from the anaerobic digestion (AD) of food waste (FW). The adaptability of air nanobubble water (Air-NBW) domesticated inoculum with the rise of the salinity (1% to 3%) was investigated in this study. Moreover, the methanogenic properties of the AD of FW at the salinity of 3% using domesticated inoculum were examined at a range of inoculation ratios (I/S, (volatile solids (VS) basis)). As indicated by the results of this study, the methane yield of the Air-NBW group was improved by 31%, 18%, and 16% compared with the control group in the three phases, respectively. Notably, the lag period in the Air-NBW group was shortened with the rise of the salinity, particularly at the salinity of 2% where the lag period was reduced by 14 d compared with the control group. Furthermore, the methanogenesis performance was enhanced with the decrease in the I/S ratio, whereas the corresponding operation period was extended by 36 d. As revealed by the result of this study, a salinity-adaptable inoculum could facilitate the rapid startup and stable operation of FW digesters.