| 长期暴露下纳米二氧化钛对典型淡水藻体砷累积与生物转化的影响 |
| 摘要点击 3065 全文点击 1031 投稿时间：2016-08-19 修订日期：2016-09-11 |
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| 中文关键词 长期暴露 藻 As(Ⅴ) 纳米颗粒 形态 |
| 英文关键词 long-term exposure algae arsenate nanoparticles speciation |
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| 中文摘要 |
| 以铜绿微囊藻（Microcystis aeruginosa）和斜生栅藻（Scenedesmus obliquus）为研究对象，通过室内培养实验，研究了长期暴露下纳米二氧化钛（nano-TiO2）对五价砷[ As（Ⅴ）]在典型淡水藻体中累积与生物转化的影响.结果表明不同藻类对无机砷的吸收和转化能力差异很大.长期暴露下斜生栅藻累积的砷（As，以DW计，下同）高达（819.66±11.25）μg·g-1，比铜绿微囊藻累积的As [（355.95±8.31）μg·g-1 ]高2倍多.Nano-TiO2可增加藻体对As的吸收累积，降低了培养基中As的含量.同时，nano-TiO2可增加藻体对As（Ⅴ）的生化转化；其中，铜绿微囊藻中有机砷以二甲基砷（DMA）为主，而斜生栅藻中有机砷以一甲基砷（MMA）为主.另外，长期暴露下nano-TiO2处理的铜绿微囊藻和斜生栅藻向培养基释放的甲基砷小于对照组，表明长期暴露中的nano-TiO2不能促进藻体内甲基砷的释放.研究结果可促进nano-TiO2与As相互作用时生态风险的理解. |
| 英文摘要 |
| In the present study, the accumulation and biotransformation of arsenate in typical freshwater algae species were examined under long-term influence of titanium dioxide nanoparticles (nano-TiO2). Results showed that different algae species had largely varied capacities of accumulation and biotransformation of arsenate. The arsenic accumulation reached (819.66±11.25) μg·g-1 DW in Scenedesmus obliquus, which was higher than that in Microcystis aeruginosa of (355.95±8.31) μg·g-1 DW. Nano-TiO2 increased arsenic accumulation in these exposed algae species, and then reduced arsenic levels in the relative culture media. Furthermore, nano-TiO2 improved arsenic biotransformation in the exposed algae, and the organic arsenic was dimethylarsinous acid (DMA) and monomethylarsonous acid (MMA) in Microcystis aeruginosa and Scenedesmus obliquus, respectively. Additionally, the release of organic arsenic was lower from the exposed algae in nano-TiO2 treatments than in the control, indicating that nano-TiO2 couldn't stimulate the release of organic arsenic from algae under long-term exposure. These results could improve insights on the ecological risk of nano-TiO2 associated with arsenic in the environment. |
