Effects of cod:sulfate ratio on sulfate removal from oil shale retort water using microbial fuel cells
West Virginia University, Department of Civil and Environmental Engineering, Morgantown, WV 26506, USA
Abstract
This paper reports the effects of COD:sulfate ratio on sulfate removal and electricity generation from oil shale retort water treatment using microbial fuel cells (MFCs). Field-collected retort water was augmented with organics to obtain a range of initial COD:SO42- ratios (0.5:1 to 2:1), and treated in two different MFC designs (tubular and two-chambered). The two-chambered MFCs exhibited COD and sulfate removal 1 to 2 orders of magnitude higher than those of the tubular MFCs. The tubular MFCs did not exhibit a significant dependence of sulfate removal on the COD:SO42- ratio while the two-chambered MFCs showed a positive trend. The tubular MFCs generated a maximum power density of 19 mW/m2 (COD:SO42-= 1.5:1), and the two-chambered MFCs produced 120 mW/m2 (2:1). The results suggest that organic carbon loading to the MFCs should be determined based on the sulfate concentration and reactor design to achieve optimal sulfate removal and electric power output.
Keywords
COD:sulfate ratio; microbial fuel cells; oil shale retort water; sulfate removal