Operation characteristics of biohydrogen production in continuous flow anaerobic system for treating wastewater of beet-sugar processing

The feasibility and operation characteristics of anaerobic fermentation biohydrogen production in a continuous stirred-tank reactor (CSTR) were investigated for treating beet-sugar processing wastewater. The research indicates that the reactor has the capacity of continuously producing hydrogen in an initial biomass (as volatile suspension solids) of 17.74 g/L, temperature of (35±1)°C, hydraulic retention time (HRT) of 6 h, and the reactor can start up the ethanol-type fermentation with COD organic loading rate (OLR) in 12 d and realize stable hydrogen production. Furthermore, the CSTR reactor enjoys a favorable stability even with an organic shock loading. When the organic loading rate (as COD) rises from 8 kg/(m³·d) to 24 kg/(m³·d), the CSTR system can reach a new steady state within 9 d. COD removal rate increases from 8% to 20%, the biogases yield increases from 3 L/d to 12 L/d, and the hydrogen volume fraction in the biogas is 67%.