2013 Volume 11 Issue 5 Pages 463-475
Feasibility study of an up-flow staged sludge bed (USSB) for treatment of starch wastewater industry was investigated. The bioreactor was examined under both acidogenesis and methanogenesis conditions for hydrogen and methane production, respectively. The acidogenic reactor was operated at a hydraulic retention time (HRT) of 8 h and organic loading rate (OLR) of 60.0 ± 6.6 kg-COD/(m3•d). Hydrogen yield was 312.5 ± 26.2 L-H2/kg-COD-removed representing 22.5% of the theoretical value. At longer HRT of 24 h and OLR of 20.0 ± 2.2 kg-COD/(m3•d), 41.0 ± 3.6% of the total influent COD was converted to methane, and amounted to 240.0 ± 18.1 L-CH4/kg-COD-removed which represented 68% of the theoretical value. These results were used to estimate the cost and economic analysis of a full scale starch wastewater treatment plant treating 300 m3/d. Environmental benefits provided an additional profits to enhance the cash-flow analysis. The economic analysis revealed that, starch wastewater treatment plant would return its investment in a payback period of 1.9 ± 0.1 and 1.8 ± 0.1 years, with an energy profit of 22 and 11.23 US$/GJ in terms of hydrogen and methane production, respectively.
