초록
The present study dealt with hydrogen and methane production in a sequential up-flow anaerobic sludge blanket (UASB) and continuous stirred tank reactor (CSTR) at thermophilic temperature. The POME was used as a suitable substrate of carbon source. The effect of various OLR was investigated from 25kg-COD/m<SUP>3</SUP>.d to 125kg-COD/m<SUP>3</SUP>.d at a constant hydraulic retention time (HRT) of 6h. The UASB-H<SUB>2</SUB> reactor was operated successfully at the OLR of 75kg-COD/m<SUP>3</SUP>.d when the proportion of H<SUB>2</SUB> in biogas, volumetric production rate of H<SUB>2</SUB>, specific hydrogen production rate (SHPR) and H<SUB>2</SUB> yield reached the maximum values of 35%, 2.1l/d, 175.15ml H<SUB>2</SUB>/g MLVSS-d and 49.22ml H<SUB>2</SUB>/g COD<SUB>applied</SUB> respectively. Further, the effluent from the UASB was directly fed into the CSTR at various OLR ranging from 4kg-COD/m<SUP>3</SUP>.d to 20kg-COD/m<SUP>3</SUP>.d for CH<SUB>4</SUB> production. The maximum CH<SUB>4</SUB> content, volumetric production rate of CH<SUB>4</SUB>, specific methane production rate (SMPR) and CH<SUB>4</SUB> yield obtained were 65%, 13l/d, 325.13ml CH<SUB>4</SUB>/g MLVSS-d, and 155.87ml CH<SUB>4</SUB>/g COD<SUB>applied</SUB> respectively. The effluent from CH<SUB>4</SUB> reactor was recycled at feed flow rate recycle ratio of 1:1 to UASB unit and pH was maintained at 5.5, subsequently resulted in COD removal of 85%.