Distribution and speciation of mercury in soil in the area of an ancient mercury ore roasting site,Frbejžene trate (Idrija area,Slovenia)     

Tamara Teršič  Mateja Gosar  Harald Biester 《Journal of Geochemical Exploration》2011

In the initial period of mining activities in the Idrija basin (the16^th and the first half of the17^th centuries), Hg ore processing was performed at various small-scale roasting sites in the woods surrounding Idrija, by roasting ore in earthen vessels. The recovery rate of this method was very low; about half of Hg was lost, causing soil contamination and considerable amounts of waste material that could potentially leach Hg into the surrounding environment. The main aims of present geochemical study were to determine the contents, vertical distribution and speciation of Hg in soils at the roasting site at Frbej?ene trate in order to verify the extreme pollution of ancient Hg ore roasting sites in the Idrija area and to establish their significance in the wider spatial contamination of soils and aquatic systems. Soil sampling was performed at the area of the former roasting site. The organic matter-rich surface soil layer (SOM) and underlying mineral soil were sampled at 63 sampling locations. Mercury speciation was performed using Hg thermo-desorption-AAS to distinguish cinnabar from potentially bioavailable forms. The results indicate extremely high Hg concentrations with a maximum of 37,000 mg/kg in SOM and 19,900 mg/kg in mineral soil. The established Hg median in soil was 370 mg/kg and in SOM 96.3 mg/kg. Spatial distributions of Hg in SOM and soil showed very high Hg contents in the central area and decreased rapidly with distance. The results of Hg thermo-desorption measurements indicated the presence of cinnabar (HgS) and Hg bound to organic or mineral soil matter. A significant portion (35–40%) of Hg in the investigated soil and SOM samples was comprised of non-cinnabar compounds, which are potentially bioavailable. It has been shown that soils contain high amounts of potentially transformable non-cinnabar Hg, which is available for surface leaching and runoff into the surrounding environment. Therefore, contaminated soils and roasted residues at the studied area are important for persistent Hg release into the aquatic ecosystem.  相似文献   

污泥/煤流化床混烧底灰中的重金属毒性研究     

赵晓莉  朱伟  徐德福  邱林倩  张超  杨创 《南京气象学院学报》2013,5(3):244-250

研究了污泥与煤按不同质量比例混烧后,底灰中的重金属形态分布与浸出毒性.结果表明:30:70的泥煤比使底灰中重金属硫化物及有机态和残渣态所占比例最大,即生物无效部分比例最大;在浸出毒性实验中,30:70的泥煤比使底灰重金属浸出量最小.由此推出,对环境毒害程度最小的泥煤质量比为30:70,即该实验条件下最优泥煤质量比为30:70.  相似文献   

Sulfur Speciation in Hydrothermal Fluids     

NI Huaiwei  Hans KEPPLER 《《地质学报》英文版》2013,87(Z1):263-263

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Geochemical speciation and spatial distributions of phosphorus in surface sediments from the basin of the Marcus-Wake seamounts in the western Pacific Ocean     

Chao Yuan  Fansheng Meng  Xuying Yao  Jianyu Ni 《海洋学报(英文版)》2022,41(4):80-90

The concentrations of five forms of phosphorus(P) including exchangeable or loosely adsorbed P(Ex-P), Febound P(Fe-P), authigenic P(Auth-P), detrital P(Det-P), and organic P(Org-P) from the basin among the Marcus-Wake seamounts(19.4°–24°N, 156.5°–161.5°E) in the western Pacific Ocean were quantified using a sequential extraction method(SEDEX) to investigate the distribution and sources of different P species.Concentrations of total P(TP) varied from 14.0 μmol/g to 44.1 μmol/g, with an average of...  相似文献   

Speciation analysis of metals （Tl, Cd and Pb） in Tl-containing pyrite and its cinder from Yunfu Mine, China, by ICP-MS with sequential extraction   总被引：1，自引：0，他引：1  

Chunlin Wang  Yongheng Chen  Jianyang Pan  Ping Zhang  Jianying Qi  Juan Liu  Xiangping Li  Jin Wang 《中国地球化学学报》2010,29(1):113-119

The speciation of heavy metals such as thallium, cadmium and lead existing in pyrite and pyrite cinder was analyzed by ICP-MS with a sequential extraction procedure. The distribution patterns of these metals including exchangeable, reducible, oxidizable and residual fractions were obtained. Tl, Cd and Pb in pyrite and pyrite cinder samples from each extraction step were determined by inductively coupled plasma mass spectrometry (ICP-MS). Under the optimized instrumental conditions, detection limits of Tl, Cd and Pb in different matrices were within the range of 0.006–0.07 μg/L, and the relative standard deviations ranged from 0.8% to 1.2%. The accuracy of Tl, Cd and Pb determination was checked by analyzing two certified reference materials. The results demonstrate that trace Tl, Cd and Pb in the samples can be accurately determined. The sequential extraction results revealed that the percent contents of Tl, Cd and Pb in exchangeable, reducible and oxidizable fractions in pyrite cinder are different from those in pyrite and in pyrite cinder. Tl, Cd and Pb mostly are distributed in residual fraction. Therefore, the mobility of metals in pyrite is higher than that in pyrite cinder. Although distributions of Tl, Cd and Pb in the non-residual fraction are not dominant in pyrite cinder, the total concentrations of them could not be ignored. Consequently, attention must be paid to the risk of potential pollution by pyrite cinder.  相似文献   

江西省鄱阳湖流域根系土硒形态分析及其迁移富集规律   总被引：5，自引：0，他引：5  

魏然  侯青叶  杨忠芳  尹国胜  衷存堤  邓国辉  马逸麟 《物探与化探》2012,(1):109-113

对江西省鄱阳湖流域根系土中硒的形态分析表明,根系土中Se的强有机态、腐植酸结合态约占Se全量的66.23%,残渣态占12.32%,3种形态均与根系土Se全量呈极显著的线性正相关。根系土Se全量受pH值的影响不明显,但受有机质含量的影响很大,线性回归关系极显著,说明岩石风化、土壤发育过程中,有机质吸附Se,致使Se较其他元素流失比例少,造成根系土中Se相对富集。同时,提出了利用全量Se推导Se各形态值的方法,建立了土壤Se全量与各形态间的关系模型和决定土壤有效态Se的公式,建议在评价土壤Se时只用考虑有机结合态Se、残渣态Se、水溶态Se和全量Se。  相似文献   

呼和浩特市大气降尘中镉赋存形态分析   总被引：3，自引：0，他引：3  

赵锁志  王沛东  包凤琴  高征西  樊永刚  钟仁  张宝 《岩矿测试》2009,28(4):329-332

采用Tessier连续提取法对呼和浩特市不同区域的9个大气降尘样品中镉的赋存形态进行了研究。结果表明,各形态含量在总镉中所占比例由大到小排列顺序依次是:铁锰氧化物结合态>残渣态>碳酸盐结合态>强有机结合态>可交换态。大气降尘中镉的5种形态占总镉的平均质量分数由大到小为:铁锰氧化物结合态31.80%,残渣态24.42%,碳酸盐结合态19.04%,强有机结合态14.61%,可交换态10.13%;铁锰氧化物结合态是主要存在形态;铁锰氧化物结合态镉、有机结合态镉、残留态镉这三种形态镉生物有效性很低,但当环境改变时可能发生镉释放,应予以关注。汽油和煤的燃烧以及工厂排放镉能加大城市大气降尘中的镉含量。  相似文献   

A comparison of iron limitation of phytoplankton in natural oceanic waters and laboratory media conditioned with EDTA     

L. J. A. Gerringa  H. J. W. de Baar  K. R. Timmermans 《Marine Chemistry》2000,68(4)

The solubility of iron in oxic waters is so low that iron can be a limiting nutrient for phytoplankton growth in the open ocean. In order to mimic low iron concentrations in algal cultures, Ethylenediaminetetraacetate (EDTA) is commonly used. The presence of EDTA enables culture experiments to be performed at a low free metal concentration, while the total metal concentrations are high. Using EDTA provides for a more reproducible medium. In this study Fe speciation, as defined by EDTA in culture media, is compared with complexation by natural organic complexes in ocean water where Fe is thought to be limited. To grow oceanic species into iron limitation, a concentration of at least 10⁻⁴ M EDTA is necessary. Only then does the calculated [Fe³⁺] concentrations resemble those found in natural sea water, where the speciation is governed by natural dissolved organic ligands at nanomolar concentrations. Moreover, EDTA influences the redox speciation of iron, and thus frustrates research on the preferred source of Fe-uptake, Fe(III) or Fe(II), by algae. Nowadays, one can measure the extent of natural organic complexation in sea water, as well as the dissolved Fe(II) state, and can use ultra clean techniques in order to prevent contamination. Therefore, it is advisable to work with more natural conditions and not use EDTA to create iron limitation. This is especially important when the biological availability of the different chemical fractions of iron are the subject of research. Typically, many oceanic algae in the smallest size classes can still grow at very low ambient Fe and are not easily cultivated into limitation under ambient sea water conditions. However, the important class of large oceanic algae responsible for the major blooms and the large scale cycling of carbon, silicon and other elements, commonly has a high Fe requirement and can be grown into Fe limitation in ambient seawater.  相似文献   

生物样品中硒形态分析前处理技术     

张绿茵  余晓平  郭亚飞  邓天龙 《岩矿测试》2012,31(3):407-412

样品前处理过程在硒形态分析中至关重要。文章对生物样品中硒形态分析的前处理方法,包括液相萃取、微波辅助萃取、固相微萃取、液相微萃取等及其应用进行归纳总结,指出了痕量、超痕量硒形态分析前处理技术的未来发展方向主要集中在满足简单、快速和环境友好的自动化处理,并着重于样品前处理的各种萃取技术在线耦合以及与硒形态分析检测器联用技术。  相似文献   

新疆某地浸砂岩型铀矿中铀赋存形态的研究   总被引：3，自引：2，他引：1  

马强  冯志刚  孙静  谢二举  李小军 《岩矿测试》2012,31(3):501-506

以新疆某地浸砂岩型铀矿为研究对象,参考Tessier逐级化学提取方法,对10件矿芯试样进行铀赋存形态的研究。将铀赋存形态分为可交换离子态、碳酸盐结合态、铁锰氧化物结合态、硫化物及有机物结合态和残渣态,其中前4种形态铀为活性铀,残渣态铀为惰性铀。研究结果显示,无论是试样间还是同一试样内,铀的形态分布特征都存在明显的差异。各形态铀的含量(平均值)占总量铀的比例为:残渣态(37.75%,RSD为1.80%)>碳酸盐结合态(20.56%,RSD为2.72%)>可交换离子态(15.51%,RSD为1.85%)>硫化物及有机物结合态(14.26%,RSD为2.08%)>铁锰氧化物结合态(11.91%,RSD为1.75%),表明残渣态铀是砂岩型铀矿石中铀的重要赋存形式。针对目前酸法地浸工艺,活性铀是可被浸出的部分,而惰性铀对资源回收是无效的,对于残渣态铀所占比例较高的铀矿石,铀的浸出值较低,在地浸过程中依靠提高溶浸剂的酸度和增加氧化剂对提高浸出率是无益的。  相似文献