Department of Frontier Materials and Function Engineering, Iwate University, Ueda 4-3-5, Morioka 020-8551, Japan.
Water Res. 2012 Oct 1;46(15):4825-31. doi: 10.1016/j.watres.2012.06.013. Epub 2012 Jun 20.
Biological oxidation of arsenite (As(III)) in synthetic groundwater was examined by using arsenite oxidising bacteria (AOB) isolated from an activated sludge. The phylogenetic analysis indicated that the isolated AOB was closely related to Ensifer adhaerens. Batch experiments showed that for an As(III) oxidation with the isolated AOB the optimum ratio of nitrogen source (NH₄-N) concentration to As(III) concentration was 0.5 (52 mg/L-110 mg/L) and the isolated AOB preferred pH values ranging from 6 to 8, and water temperatures greater than 20 °C. Further continuous experiments were conducted using a bioreactor with immobilised AOB. With an initial As(III) concentration of 1 mg/L at a hydraulic retention time (HRT) of 1 h, an As(III) oxidation rate was around 1 × 10⁻⁹ μg/cell/min and an As(III) oxidation efficiency of 92% was achieved. Although the maximum oxidation rate measured at an HRT of 0.5 h was 2.1 × 10⁻⁹ μg/cell/min, the oxidation efficiency decreased to 87%. These results advocate that a biological process involving immobilised AOB may be useful as an economical and environmentally friendly pre-treatment step for As removal from groundwater.
采用从活性污泥中分离出的亚砷酸盐氧化菌（AOB）研究了合成地下水中亚砷酸盐（As(III)）的生物氧化。系统发育分析表明，分离出的 AOB 与 Adhaerens 属的 Ensifer 密切相关。批式实验表明，对于用分离的 AOB 进行的 As(III)氧化，氮源（NH₄-N）浓度与 As(III)浓度的最佳比值为 0.5（52mg/L-110mg/L），并且分离的 AOB 优先选择 pH 值范围为 6 到 8，以及温度大于 20°C。进一步使用固定化 AOB 的生物反应器进行连续实验。初始 As(III)浓度为 1mg/L，水力停留时间（HRT）为 1h，As(III)氧化速率约为 1×10⁻⁹μg/细胞/分钟，氧化效率达到 92%。尽管在 HRT 为 0.5h 时测量的最大氧化速率为 2.1×10⁻⁹μg/细胞/分钟，但氧化效率下降至 87%。这些结果表明，涉及固定化 AOB 的生物过程可能是从地下水中去除砷的一种经济且环保的预处理步骤。
