Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada, N9B 3P4.
Environ Sci Technol. 2012 Oct 16;46(20):11086-94. doi: 10.1021/es302292d. Epub 2012 Oct 4.
Thallium (Tl) is emerging as a metal of concern in countries such as China due to its release during the natural weathering of Tl-bearing ore deposits and mining activities. Despite the high toxicity of Tl, few studies have examined the reductive dissolution of Tl mineral phases by microbial populations. In this study we examined the dissolution of synthetic Tl(I)-jarosite, (H(3)O)(0.29)Tl(0.71)Fe(2.74)(SO(4))(2)(OH)(5.22)(H(2)O)(0.78), by Shewanella putrefaciens CN32 using batch experiments under anaerobic circumneutral conditions. Fe(II) concentrations were measured over time and showed Fe(II) production (4.6 mM) in inoculated samples by 893 h not seen in mineral and dead cell controls. Release of aqueous Tl was enhanced in inoculated samples whereby maximum concentrations in inoculated and cell-free samples reached 3.2 and 2.1 mM, respectively, by termination of the experiment. Complementary batch Tl/S. putrefaciens sorption experiments were conducted under experimentally relevant pH (5 and 6.3) at a Tl concentration of 35 μM and did not show significant Tl accumulation by either live or dead cells. Therefore, in contrast to many metals such as Pb and Cd, S. putrefaciens does not represent a sink for Tl in the environment and Tl is readily released from Tl-jarosite during both abiotic and biotic dissolution.
铊（Tl）在中国等国家作为一种关注的金属而出现，这是由于其在含铊矿床的自然风化和采矿活动中释放。尽管铊的毒性很高，但很少有研究考察微生物种群对 Tl 矿物相的还原溶解作用。在这项研究中，我们在厌氧中性条件下使用批处理实验，研究了施氏假单胞菌 CN32 对合成 Tl（I）-黄钾铁矾，（H(3)O)(0.29)Tl(0.71)Fe(2.74)(SO(4))(2)(OH)(5.22)(H(2)O)(0.78)的溶解作用。随着时间的推移测量了 Fe(II)浓度，结果表明，接种样本中 Fe(II)的生成（4.6 mM）在 893 h 内没有在矿物和死细胞对照中看到。接种样本中释放的水合铊增加，在实验结束时，接种和无细胞样本中的最大浓度分别达到 3.2 和 2.1 mM。进行了补充的批处理 Tl/S. 施氏假单胞菌吸附实验，在实验相关的 pH 值（5 和 6.3）下进行，铊浓度为 35 μM，无论是活细胞还是死细胞都没有显示出明显的 Tl 积累。因此，与许多金属（如 Pb 和 Cd）不同，施氏假单胞菌在环境中不是 Tl 的汇，并且在非生物和生物溶解过程中，Tl 很容易从 Tl-jarosite 中释放出来。
