Bednar A J, Jones W T, Boyd R E, Ringelberg D B, Larson S L
U.S. Army Engineer Research and Development Center, Environmental Lab., 3909 Halls Ferry Rd., Vicksburg, MS 39180, USA.
J Environ Qual. 2008 Jan 4;37(1):229-33. doi: 10.2134/jeq2007.0305. Print 2008 Jan-Feb.
The biogeochemistry of tungsten and its effects on mobility have recently gained attention due to the existence of human cancer clusters, such as in Fallon, NV. Tungsten exists in many environmental matrices as the soluble and mobile tungstate anion. However, tungsten can polymerize with itself and other anions, creating poly- and heteropoly-tungstates with variable geochemical and toxicological properties. In the present work, geochemical parameters are determined for tungstate species in a model soil that describe the potential for tungsten mobility. Soluble tungsten leached from a metallic tungsten-spiked soil after six to twelve months aging reached an equilibrium concentration >150 mg/L within 4 h of extraction with deionized water. Partition coefficients determined for various tungstate and polytungstate compounds in the model soil suggest a dynamic system in which speciation changes over time affect tungsten geochemical behavior. Partition coefficients for tungstate and some poly-species have been observed to increase by a factor of 3 to 6 over a four month period, indicating decreased mobility with soil aging.
由于人类癌症聚集区的存在，如内华达州法伦，钨的生物地球化学及其对迁移性的影响最近受到了关注。钨在许多环境基质中以可溶性且可移动的钨酸根阴离子形式存在。然而，钨可自身聚合以及与其他阴离子聚合，形成具有可变地球化学和毒理学性质的聚钨酸盐和杂多钨酸盐。在本研究中，测定了描述钨迁移潜力的模型土壤中钨酸盐物种的地球化学参数。用金属钨加标土壤老化六至十二个月后，用去离子水提取4小时内，从土壤中浸出的可溶性钨达到平衡浓度>150mg/L。在模型土壤中测定的各种钨酸盐和聚钨酸盐化合物的分配系数表明，这是一个动态系统，其中随时间变化的物种形成会影响钨的地球化学行为。观察到钨酸盐和一些多物种的分配系数在四个月内增加了3至6倍，表明随着土壤老化迁移性降低。
