Pb(II) distributions at biofilm–metal oxide interfaces
Pb(II) distributions at biofilm–metal oxide interfaces
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DOI：
10.1073/pnas.201150998
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发表时间：
2001-09
影响因子：
11.1
通讯作者：
A. Templeton;T. Trainor;S. Traína;A. Spormann;G. Brown
中科院分区：
文献类型：
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作者：
A. Templeton;T. Trainor;S. Traína;A. Spormann;G. Brown
用长周期X射线驻波技术研究了洋葱伯克霍尔德菌生物膜与赤铁矿（α-Fe_2 O_3）或氧化铝（α-Al_2 O_3）界面上吸附的Pb（Ⅱ）的分布。附着的细菌和吸附的有机物可能会通过改变固溶体界面处的双电层的特性、阻断表面位点或提供各种新的金属结合位点来干扰金属氧化物表面上的吸附过程。在这项工作中，Pb Lα荧光产率曲线的平衡与10−7至10−3.8 M Pb（II）的样品进行了测量和建模，以确定定量的Pb（II）在生物膜的分配金属氧化物界面。我们的数据表明，金属氧化物表面上的反应位点没有钝化的单层生物膜的形成。相反，金属氧化物上的高能表面位点在亚微摩尔浓度下形成了Pb（II）的主要汇，遵循α-Fe 2 O3（0001）> α-Al 2 O3（11 μ 02）> α-Al 2 O3（0001）的趋势，尽管上覆生物膜内的位点密度更大。在[Pb] > 10−6 M时，观察到生物膜对Pb的显著吸收。
The distribution of aqueous Pb(II) sorbed at the interface between Burkholderia cepacia biofilms and hematite (α-Fe2O3) or corundum (α-Al2O3) surfaces has been probed by using an application of the long-period x-ray standing wave technique. Attached bacteria and adsorbed organic matter may interfere with sorption processes on metal oxide surfaces by changing the characteristics of the electrical double layer at the solid–solution interface, blocking surface sites, or providing a variety of new sites for metal binding. In this work, Pb Lα fluorescence yield profiles for samples equilibrated with 10−7 to 10−3.8 M Pb(II) were measured and modeled to determine quantitatively the partitioning of Pb(II) at the biofilm–metal oxide interface. Our data show that the reactive sites on the metal oxide surfaces were not passivated by the formation of a monolayer biofilm. Instead, high-energy surface sites on the metal oxides form the dominant sink for Pb(II) at submicromolar concentrations, following the trend α-Fe2O3 (0001) > α-Al2O3 (11̄02) > α-Al2O3 (0001), despite the greater site density within the overlying biofilms. At [Pb] > 10−6 M, significant Pb uptake by the biofilms was observed.