Biohydrogen production from starchy wastewater in upflow anaerobic sludge blanket (UASB) reactor: Possibilities toward circular bioeconomy

The present study investigates the performance of upflow anaerobic sludge blanket (UASB) reactor for stable H2 production from starchy wastewater supplemented with groundnut de-oiled cake using mixed consortia. Insufficient reports are available on H2 production for UASB reactor. Operation of the UASB reactor was divided into two stages i.e., start-up period where desirable sludge height was developed and production period where different hydraulic retention time (HRT) was examined for H2 production. The maximum H2 production rate of 12.3 L L−1 d−1was observed at 3 h HRT. Details physicochemical characteristics of the granular sludge were studied using SEM-EDX image, FTIR spectra, particle size analyser, SVI value, EPS and metal content. Kinetic analysis of the process revealed that Grau, and modified Stover-Kicannon were the most suitable for H2 producing UASB reactor. This is the first report to implement these advanced bio-kinetic models of substrate consumption on hydrogen production in UASB reactor. Furthermore, a potential toward circular bioeconomy model has been discussed for the accomplishment of maximum resource recovery with a minimum waste generation.