Zhang Yiqiang, Okeke Benedict C, Frankenberger William T
Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
Bioresour Technol. 2008 Mar;99(5):1267-73. doi: 10.1016/j.biortech.2007.02.048. Epub 2007 May 18.
Selecting an inexpensive and effective organic carbon source is the key to reducing the cost in selenium (Se) remediation. Five bacteria were screened based on their ability in using molasses as an organic carbon source to reduce selenate [Se(VI)] in drainage water. Efficiency of Se removal differed in the molasses-added drainage water containing different bacteria, with an order of Enterobacter taylorae>Pantoea sp. SSS2>Klebsiella sp. WRS2>Citerobacter freundii>Shigella sp. DW2. By using E. taylorae, 97% of the added Se(VI) (1000 microg/L) was reduced to elemental Se [Se(0)] in an artificial drainage water during an 11-day experiment, and 93% of Se(VI) in a natural agricultural drainage water was reduced to Se(0) and organic Se during a 7-day experiment. E. taylorae also rapidly removed Se(VI) in agar-coated sand columns. During 45 days of the experiment, more than 92% of influent Se was removed from the drainage water with a molasses range of 0.01-0.1%. This study reveals that molasses may be a cost-effective organic carbon source used by Se(VI)-reducing bacteria to remove Se from agricultural drainage water in field.
选择一种廉价且有效的有机碳源是降低硒修复成本的关键。基于五种细菌利用糖蜜作为有机碳源还原排水中硒酸盐[Se(VI)]的能力对它们进行了筛选。在添加了糖蜜的含有不同细菌的排水中，硒的去除效率有所不同，顺序为泰勒肠杆菌>泛菌属SSS2>克雷伯菌属WRS2>弗氏柠檬酸杆菌>志贺氏菌属DW2。在为期11天的实验中，使用泰勒肠杆菌可将人工排水中添加的97%的Se(VI)(1000μg/L)还原为元素硒[Se(0)]，在为期7天的实验中，可将天然农业排水中93%的Se(VI)还原为Se(0)和有机硒。泰勒肠杆菌还能在琼脂包覆的砂柱中快速去除Se(VI)。在为期45天的实验中，糖蜜添加量在0.01%至0.1%范围内时，排水中超过92%的进水硒被去除。本研究表明，糖蜜可能是一种具有成本效益的有机碳源，可供还原Se(VI)的细菌用于从田间农业排水中去除硒。
