1、Proposal of a simple screening method for a rapid preliminary evaluation of “heavy metals” mobility in soils of contaminated sites Valentina Pinto & Francesca Chiusolo & Carlo Cremisini Received: 23 June 2009 / Accepted: 22 February 2010 # Springer-Verlag 2010 Abstract Purpose Risks associated to “h
2、eavy metals” (HM) soi contamination depend not only on their total content but, mostly, on their mobility. Many extraction procedures have been developed to evaluate HM mobility in contaminated soils, but they are generally time consuming (especially the sequential extraction procedures (SEPs) and c
3、onsequently applicable on a limited number of samples. For this reason, a simple screening method, applicable even “in field”, has been proposed in order to obtain a rapid evaluation of HM mobility in polluted soils, mainly focused on the fraction associated to Fe and Mn oxide/hydroxides。 对土壤中的重金属的污
4、染的迁移性的初步 快速的简单的筛选 测定 方法的建议 （摘要） （对“重金属”在土壤中的污染 风险联系 不只局限于他们的总重量， 通常来说，和他的迁移转化有关 。 在 污染的土壤中很多 萃取方法 被又来评价重金属的迁移转化 ，但他们随着时间的而变 特别是 连续抽样， 因此适用于有限数量的样本 。由于这个原因， 已提出建议，以获得一个快速的适用工作现场 ，甚至一个简单的筛选方法 来重金属在土壤中的污染迁移转化， 主要侧重于相关联的铁和锰的 氢氧化物 的分数 。 ） Materials and methods A buffer solution of trisodium citrate and h
5、ydroxylamine hydrochloride was used as extractant for a single-step leaching test. The choice of this buffered solution was strictly related to the possibility of directly determining, via titration with dithizone (DZ), the content of Zn, Cu, Pb and Cd, which are among the mostrepresentative contami
6、nants in highly mineralised soils. Moreover, the extraction solution is similar, aside from for the pH value, which is the one used in the BCR SEP second step. The analysis of bivalents ions through DZ titration was exploited in order to further simplify and quicken the whole procedure. The proposed
7、 method generically measures, in few minutes, the concentration of total extractable “heavy metals” expressed as molL1 without distinguishing between elements。 我们 是用的材料和方法 A 缓冲溶液的钠枸橼酸和羟胺盐酸 作为萃取剂一步浸出试验 。 此缓冲的解决方案的选择是密切相关的直接测定可能性 ， 滴定法双硫腙 （ DZ） ，锌、 铜、 铅镉的内容通过，当中 污染的不准确性是污染物中土壤中很高的矿化原因。 此外，在 BCR 体感诱发电位
8、的第二步中 ， 使用类似提取解决方案 时要出去 PH值， 从而 进一步简化和 加速整个过程 被利用 二价 离子通过 DZ滴定分析 Results and discussion The proposed screening method has been developed and applied on soil samples collected from rural, urban and mining areas, representing different situation of soil contamination. Results were compared with data o
9、btained from the BCR procedure . Conclusions The screening method demonstrated to be a reliable tool for a rapid evaluation of metals mobility. Therefore, it could be very useful, even “in field”, both to guide the sampling activity on site and to monitor the efficacy of the subsequent remediation a
10、ction。 对于 收集来自农村、 城市和采矿地区代表土壤污染的不同情况的土壤样品结果及建议的筛选方法探讨已开发和应用 。然后 结果是与从 BCR 过程中获得的数据进行比较 。 结论 证明：筛选方法是一个可靠 评价金属转移快慢的工具。因此，在 工作现场它可能是非常有用 ，甚至两个站点上指导采样活动和留意后续修复操作的效果 。 Keywords Dithizone . Extraction procedures . In-field test . 双硫腙关键字。 抽取过程。 在现场试验 Metals mobility . Screening method 金属流动性。 筛选方法 1 Introd
11、uction The environmental impact of soil contamination by toxicologically relevant metals depends not only on the total concentration but mostly on the form in which metals occur, their mobility and, consequently, bioavailability (Alloway 2005). Risks become relevant in the following 土壤中对有毒金属污染的不仅取决于
12、他的总浓度，通常还和金属的反应，流动性，生物作用有关 风险成为有关，以下 所示： cases: & medium/high levels of concentration and high mobility, but also & very high levels of concentration and moderate mobility The knowledge of trace elements mobility in contaminated soils is becoming an important requisite for any further environmental
13、evaluation: In Europe, many countries have already adopted laws used to regulate land contamination and considering pollutant bioavailability risks (Carlon 2007) and even the Soil Thematic Strategy, concerted by the European Commission in view of a future Soil Framework Directive, underlines the nee
14、d of “improvement and harmonisation of the concepts and the modeling of the transfers of contaminants from and within the soil and of the subsequent risks” (Van-Camp et al. 2004). 中等浓度或高浓度对应的流动性 而且高浓度对应的流动性 研究 受污染的土壤中痕量元素迁移的知识 成为了将来评价环境的要条件。在欧洲，许多国家已经采取将土壤污染和污染物的生物风险纳入到国家法律中甚至一些欧洲国家机构考虑到对于将来 STS的观点；
15、重视改善环境保持和谐环境的理念和重塑污染物在土壤中的迁移和 土壤中和的后续的风险 成为了土壤策略主题。 In the last decades, many single and sequential extraction procedures (SEPs) have been developed and proposed as standard methods for the study of metals mobility (Bacon and Davidson 2008； Cappuyns and Swennen 2008； Rao et al. 2008； Pacifico et al.
16、 2007). The most extensively used SEPs are the one developed by Tessier et al. (1979) and the revised BCR standardised three-step sequential extraction procedure (Rauret et al. 2000), but they are time consuming and, in general, applicable on a limited number of samples selected among a larger set.。
17、 在近几十年间，很多单独和连续提取过程已经发展成为作为研究金属流动性的标准方法。 中被 Tessier et al发现的 SEPs最广泛 的是 和 经修订的 BCR 标准化三步连续提取工艺 是最为被广泛利用的。但是他的缺点主要是它受时间的限制和对样品有选择性。 Therefore, considering that contaminated sites to be studied are often quite wide and heterogeneous with the consequential need of a large number of samples to be analys
18、ed, there is urgency of rapid and simple screening tools for a reliable identification of the most significant sampling points, in terms of metal mobility, that can be successively characterised through standard leaching test or SEPs (Fig. 1) (Brunori et al. 2005； Pacifico et al. 2007). In fact, scr
19、eening methods have some of the following characteristics: They tend to have a qualitative rather than quantitative emphasis； they normally involve little or no sample treatment； they are rapid, and the response is used for immediate decision-making, and the result obtained generally requires confir
20、mation by a conventional alternative (Valcrcel et al. 1999； Munoz-Olivas 2004). The proposal of a simple in-field screening method is based on the foregoing considerations, and in this work, a single-step leaching test has been developed and studied in order to obtain a rapid evaluation of metals mo
21、bility in polluted soils, mainly focused on the fraction associated to Fe and Mn oxide/hydroxides more dependent on the pH and oxidizing variation in the soil environment (Alloway 2005) and, qualitatively and quantitatively, more representative of the risks related to HM mobility. The proposed metho
22、d is less complex and more specific, in terms of soil fraction analysed, than other existing in-field screening systems such as the rapid test proposed by Jozic et al. (2009), which, moreover, involves reagents that create safety problems when used for in-field analysis。 因此， 考虑 到 待研究污染的场地往往相当广泛和 大量连
23、续的样品的分析，人们迫切的需要一种 快速和简单的筛选工具 来确定 重要的取样点的一个可靠的 指标。就金属流动性而言， 这可以 通过 SEPs或试验 先后特点浸出 。实际上， 有以下特征筛选方法 ： 它们的重点往往是定性分析而不是定量： 他们通常涉及很少或没有样品的处理 ； 它们快速反应和快速的反应结果， 结果通常需要确认有常规的替代 。 基于上述的考虑 建议 一种简单的 板块 筛选方法 。 为了获得在污染土壤中金属流动性的快速评价 ，所以 在这的工作单步执行浸出试验 ， 主要侧重于相关联 的 Fe和 Mn氧化物或氢氧化物的 分数 在土壤中和土壤环境的 PH值及氧化性的多样和金属流动性的风险来决
24、定是定性还是定量。 比其他 如被 Jozic et al 提出的 起初快速检测 涉及创建安全问题时用于 板块 中分析的试剂现有的字段筛选系统 ， 他提出的方法是不太复杂和更具体 的 土壤分数分析。 In the present study, a buffer solution of trisodium citrate and hydroxylamine hydrochloride at pH9.3 was used as extractant for a single-step leaching test. The choice of this buffered solution was st
25、rictly related to the possibility of directly determining, via titration with dithizone (DZ), the content of Zn, Cu, Pb and Cd, which are among the most representative contaminants in highly mineralised soils. Moreover, the extraction solution is similar, aside from the pH value, which is the one us
26、ed in the BCR SEP second step. The analysis of bivalents ions through DZ titration was exploited in order to further simplify and quicken the whole procedure。 最近研究， 钠的柠檬酸和羟胺盐酸的缓冲溶液 在 ph=9.3时 作为萃取剂用于单步执行浸出试验 。 此缓冲的解决方案的选择是密切相关的直接 决定它的 可能性 ，通过用双硫腙来滴定Zn,CuP,b,Cd,其中高矿化重金属污染的土壤最具有代表。 此外， 提取解决方案是 于 pH 值在其
27、中使用 SEP BCR的第二部类似。从而通过 通过 DZ 滴定分析 二价 离子进一步简化和 快速整个过程。 Diphenylthiocarbazone, or DZ, is an organic compound widely used, especially in the past, for the colorimetric determination of various heavy metals (Sandell 1959). DZ dissolves in most organic solvents to a greater or less extent and exists in two tautomeric forms: 二苯基硫卡巴腙 或 双硫腙 对 各种重金属含量的比色测定 是一种 使用广泛的一种有机 化合物 。
