Field and laboratory assessments on dissolution and fractionation of Pb from spent and unspent shots in the rhizosphere soil.
Field and laboratory assessments on dissolution and fractionation of Pb from spent and unspent shots in the rhizosphere soil.
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DOI：
10.1016/j.chemosphere.2013.08.095
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发表时间：
2013-11
期刊：
影响因子：
8.8
通讯作者：
Y. Hashimoto
中科院分区：
文献类型：
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作者：
Y. Hashimoto
本研究的目的是确定在实验室和现场规模的条件下，植物根系的生长对铅的溶解。在实验室研究中，进行了100天的培养实验，以评估铅的溶解从根际和非根际（散装）土壤中的未用弹（新）和用弹（>10年在田间）的毒性特征浸出程序（TCLP）和连续提取方法。这项研究发现，通过加石灰将土壤pH值提高到7.5，可以显著减少未用过和用过的弹丸（<5 mg L−1）中铅的溶解。铅在根际土壤中的溶出量大于非根际土壤。无论拍摄类型，平均TCLP-Pb浓度在酸性和石灰性土壤中的根际分别为12.9和8.1倍，比散装土壤。在野外调查中，从粘土靶靶场（<35 000 mg Pb kg−1）收集了6个不同物种的31个植物个体及其根际土壤样品。植物地上组织中的铅浓度取决于物种，平均值为72 mg kg−1（15-254 mg kg−1），远低于先前研究报告的水平。无论土壤铅水平高，地上组织铅含量的一枝黄花（即，Canada goldenrod，15 mg kg−1）和Andropogon virginicus（即，扫帚草，18毫克千克-1）低于毒性阈值，表明这些本地物种可能具有植物稳定潜力。植被对Pb的富集作用有限，这是由于废粘土靶碎片中含有丰富的土壤方解石。
The objective of this study was to determine the effect of plant root growth on Pb dissolution from shot under laboratory and field-scale conditions. For a laboratory study, a 100-d incubation experiment was conducted to assess Pb dissolution from unspent shot (new) and spent shot (>10 yr in fields) in rhizosphere and non-rhizosphere (bulk) soils using the Toxicity Characteristic Leaching Procedure (TCLP) and sequential extraction methods. This study found that increasing the soil pH value to 7.5 by liming significantly reduced Pb dissolution from unspent and spent shot (<5 mg L−1). Dissolution of Pb from shot was induced more in rhizosphere than bulk soils. Regardless of shot types, the averaged TCLP-Pb concentration in acidic and limed soils was 12.9- and 8.1-fold greater in rhizosphere than in bulk soils, respectively. For a field-scale investigation, a total of 31 individual plant samples of 6 different species and their rhizosphere soils were collected from a clay-target shooting range (<35 000 mg Pb kg−1). The Pb concentration in plant aboveground tissues depended on species with a mean value of 72 mg kg−1(15–254 mg kg−1), which was far smaller than that reported in previous studies. Regardless of high soil Pb levels, aboveground tissue Pb concentrations ofSolidago altissima(i.e., Canada goldenrod, 15 mg kg−1) andAndropogon virginicus(i.e., broomsedge, 18 mg kg−1) were below the toxicity threshold, suggesting that these indigenous species could have phytostabilization potentials. The limited Pb accumulation by vegetation was attributed to the abundance of soil calcite derived from spent clay-target fragments.