Influence of activated carbon amended ASBR on anaerobic fermentative hydrogen production

The effect of activated carbon amended ASBR on fermentative bio-hydgrogen production from glucose was evaluated at hydraulic retention time (HRTs) ranging from 48 h to 12 h with initial pH of 6.0 at the system temperature of 60°C. Experimental results showed that the performance of activated carbon amended anazrobic seguencs batch reactor (ASBRs) was more stable than that of ASBRs without activated carbon addition regarding on hydrogen production and pH.

Higher hydrogen yield(HY) and hydrogen producing rate(HPR) were observed in the activated carbon amended ASBRs, with 65%, 63%, 54%, 56% enhancement of hydrogen yield in smaller size activated carbon amended reactor under the tested HRT ranges, and the maximum HPR of (7.09±0.31)L·(L·d)-1 and HY of (1.42±0.03) mol·mol-1 was obtained at HRT of 12h.

The major soluble products form hydrogen fermentation were n-butyric acid and acetic acid, accounting for 46%~66% and 30%~34% of total soluble metabolic products(SMP), respectively, indicating that the dominant H2 producers in the mixed culture belonged to acidogenic bacteria that underwent butyrate-type fermentation.

In addition, higher concentration of volatile fatty acid (VFA) generation was observed in the activated carbon amended ASBRs.