Use of treated effluent water in ethanol production from cellulose

The bioethanol industry exerts a significant demand on water supplies. Current water consumption rate in corn dry grind ethanol plants is (11–15) dm3 m−3 of ethanol produced and (23–38) dm3 m−3 for cellulosic ethanol plants. The main goal of this study was to examine the feasibility of use of treated wastewater effluent in place of potable freshwater for cellulosic ethanol production. The effects of using two different types of filtered treated effluent; Bloomington- Normal, IL (Residential type) and Decatur, IL (Industrial/Residential Mix type); on the rate of fermentation and final ethanol yield from a pure cellulosic substrate were evaluated. Characterization analysis of both effluent water samples indicated low concentration of toxic elements. Final ethanol concentrations obtained with Bloomington- Normal and Decatur effluent and with a control treatment using de-ionized water were similar, resulting in 360 g kg−1 (0.36 g g−1), 370 g kg−1 (0.37 g g−1) and 360 g kg−1 (0.36 g g−1), respectively. These findings suggest that with proper characterization studies and under appropriate conditions, the use of treated effluent water in cellulosic ethanol production is feasible.