Start-up and operation of "sluge-micobial film" hybrid ABR used as hydrogen production system

The new sluge-micobial film hybrid anaerobic baffled reactor (SMHABR) was obtained by the improvement of the original ABR with five compartments and effective volume of 43.2 L. The experimentation studied on the formation of ethanol type fermentation, the hydrogen production capacity and the COD removal capacity. The result of 180 days experiment showed that using brown sugar wastewater as raw material with hydraulic retention time of 12 h, temperature of 35℃±1℃, the system of ethanol type fermentation bacteria could be formatted in 35 days through increasing the influent COD in a phased operation mode. When the influent COD was about 3500 mg·L^-1, the maximum hydrogen production was achieved with the total hydrogen production of 44.75 L·d^-1, The hydrogen production of the second compartment was larger than that of the other compartments. When the influent COD was about 7100 mg·L^-1, the maximum COD removal capacity was achieved with the average total COD removal rate of 49.33%. The maximum hydrogen production and the maximum COD removal rate did not appear at the same time. When the influent COD concentration was too high, the organic acid accumulation in the reactor was too much, resulting in the reactor pH down to 3. Low pH affected the hydrogen production efficiency of the system. Although ethanol fermentation was formed in the system, the hydrogen production capacity was low.