Enhanced fermentative hydrogen production from potato waste by enzymatic pretreatment

ABSTRACT

Biological pretreatment and enzymatic hydrolysis have a potential role in the economic production of sugars and fuels from starch biomass. In this study, the Inoculum/Substrate (I/S) ratio effect and enzymatic pretreatments of potato peels for biohydrogen production in batch reactors were investigated. Two enzymes, α-Amylase and Cellulase, were tested separately and coexistent. Results showed that enzymatic hydrolysis using α-Amylase in mesophilic conditions enhanced carbohydrate concentration from 24.10 g/L to 53.47 g/L, whereas, the use of Cellulase and equi-volumetric mixture of both tested enzymes resulted in 47.16 and 48.16 g/L, respectively. The maximum biohydrogen cumulative production of 263 mL (equivalent to 430.37 mL H₂/gVS_added) was obtained using the optimum I/S ratio of 1/6 gVS/gVS at pH 5.5 and incubation temperature of 55°C after 20 days of dark fermentation of potato waste without enzymatic treatment. Under the same operating conditions of the I/S ratio, pH, temperature and the best enzymatic treatment (3 h of substrate enzymatic hydrolysis by α-Amylase), the maximum yield of biohydrogen was 1088 mL (1780.39 mL H₂/gVS_added). The enzymatic hydrolysis method adopted in this study can make overall biohydrogen production an effective process. The modified Gompertz model was found to be an adequate fit for biohydrogen production.

GRAPHICAL ABSTRACT

KEYWORDS:

• Enzymatic pretreatment
• aerobic sludge
• potato peels
• biohydrogen
• α-Amylase
• BHP test

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets generated during and/or analysed during the current study are all available in the current manuscript and can be provided by the corresponding author upon reasonable request.