Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
Water Sci Technol. 2013;67(11):2637-44. doi: 10.2166/wst.2013.188.
A co-beneficial system using constructed wetlands (CWs) planted with aquatic plants is proposed for bioethanol production and nutrient removal from wastewater. The potential for bioethanol production from aquatic plant biomass was experimentally evaluated. Water hyacinth and water lettuce were selected because of their high growth rates and easy harvestability attributable to their free-floating vegetation form. The alkaline/oxidative pretreatment was selected for improving enzymatic hydrolysis of the aquatic plants. Ethanol was produced with yields of 0.14-0.17 g-ethanol/ g-biomass in a simultaneous saccharification and fermentation mode using a recombinant Escherichia coli strain or a typical yeast strain Saccharomyces cerevisiae. Subsequently, the combined benefits of the CWs planted with the aquatic plants for bioethanol production and nutrient removal were theoretically estimated. For treating domestic wastewater at 1,100 m(3)/d, it was inferred that the anoxic-oxic activated sludge process consumes energy at 3,200 MJ/d, whereas the conventional activated sludge process followed by the CW consumes only 1,800 MJ/d with ethanol production at 115 MJ/d.
提出了一种利用水生植物构建湿地(CWs)的协同系统,用于从废水中生产生物乙醇和去除营养物质。实验评估了从水生植物生物量中生产生物乙醇的潜力。水葫芦和水蕹菜因其高增长率和易于收获而被选中,这归因于它们的自由漂浮植被形式。选择碱性/氧化预处理来提高水生植物的酶水解效率。在同步糖化发酵模式下,使用重组大肠杆菌菌株或典型酵母菌株酿酒酵母,可分别获得 0.14-0.17 g-乙醇/g-生物质的乙醇产量。随后,从理论上估算了 CW 种植水生植物在生产生物乙醇和去除营养物质方面的综合效益。对于处理 1100 立方米/天的生活污水,推断缺氧-好氧活性污泥工艺消耗 3200 兆焦耳/天的能量,而传统的活性污泥工艺之后是 CW,仅消耗 1800 兆焦耳/天,同时还能生产 115 兆焦耳/天的乙醇。