Assessing the potential of inorganic anions (Cl-, NO3-, SO42- and PO43-) to increase the bioaccessibility of emitted palladium in the environment: Experimental studies with soils and a Pd model substance.
Assessing the potential of inorganic anions (Cl-, NO3-, SO42- and PO43-) to increase the bioaccessibility of emitted palladium in the environment: Experimental studies with soils and a Pd model substance.
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DOI：
10.1016/j.envpol.2016.11.039
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发表时间：
2017
影响因子：
8.9
通讯作者：
F. Zereini;C. Wiseman;Jana Poprizki;P. Albers;W. Schneider;K. Leopold
中科院分区：
文献类型：
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作者：
F. Zereini;C. Wiseman;Jana Poprizki;P. Albers;W. Schneider;K. Leopold
在过去的10-20年中，从装有排气催化转化器的车辆排放的钯（Pd）相对于其他铂族元素（PGE）以更大的速率积累。然而，很少有人知道，关于各种环境因素和条件，可能会调节该元素的化学行为和生物可及性后排放。为了满足数据需求，用含有常见阴离子（Cl−、NO3−、SO 42 −和PO 43 −）的溶液处理土壤和Pd模型物质，以揭示环境条件下排放的Pd的地球化学行为。作为其中的一部分，使用XPS检查处理过的残留物（不溶性相）和溶液（可溶性相）的颗粒表面化学，以评估在无机阴离子存在下Pd的化学转化。结果表明，在阴离子物种的存在下，Pd是最可溶的，其次是铑（Rh）和铂（Pt）。现场收集的样品中的Pd被发现是相当多的比模型物质中的金属Pd，Pd黑，用阴离子物种处理时，更容易溶解。结果还表明，钯黑的溶解度强烈依赖于溶液的pH值，浓度和反应时间。通过XPS测定，当用阴离子溶液处理时，金属Pd的外部3-4个原子层被部分氧化，程度取决于阴离子类型。发现溶液中溶解的O2浓度对金属钯的转变影响不大。考虑到所检查的阴离子的普遍存在的性质，我们可以预期Pd在发射后将变得更加生物可及。
Palladium (Pd) emitted from vehicles equipped with exhaust catalytic converters has been accumulating at a greater rate relative to other platinum group elements (PGE) in the last 10–20 years. Little is known, however, regarding the various environmental factors and conditions which are likely to modulate the chemical behavior and bioaccessibility of this element post-emission. To meet data needs, soils and a Pd model substance were treated with solutions containing common anions (Cl−, NO3−, SO42−und PO43−) to shed light on the geochemical behavior of emitted Pd under ambient conditions. As part of this, the particle surface chemistry of treated residues (insoluble phase) and solutions (soluble phase) was examined using XPS to assess the chemical transformation of Pd in the presence of inorganic anions. The results show that Pd is the most soluble in the presence of anionic species, followed by rhodium (Rh) and platinum (Pt). Pd in field-collected samples was found to be considerably more soluble than the metallic Pd in the model substance, Pd black, when treated with anionic species. The results also demonstrate that the solubility of Pd black is strongly dependent on solution pH, concentration and the duration of reaction. The outer 3–4 atomic layers of metallic Pd was determined via XPS to be partially oxidized when treated with anion solutions, with the degree being dependent on anion type. The concentration of dissolved O2in solution was found to have little impact on the transformation of metallic Pd. Given the ubiquitous nature of the anions examined, we can expect that Pd will become more bioaccessible post-emission.