Comparison of magnetic parameters with vehicular Br levels in urban roadside soils

Chemical methods are generally chosen to monitor soil pollution but magnetic measurements proved to yield additional information at low cost and less time consumption. In this investigation, the novel use of rapid and non-destructive magnetic measurements to characterize Br levels in Xuzhou (China) urban roadside soils was reported. X-ray fluorescence spectrometry (XRF) was used to quantify Br in the soil samples. Data from 21 roadside soil samples confirm Br contamination, with a mean level of 4.36 mg kg⁻¹ and a range of 2.4–8.7 mg kg⁻¹. These values are higher than that of unpolluted soils in Xuzhou that averages 1.1 mg kg⁻¹. Hierarchical clustering analysis shows Br in Xuzhou roadside soils is mainly from road traffic. Clear correlations between Br levels and simple magnetic parameters [mass specific susceptibility (χ _LF), susceptibility of anhysteretic remanent magnetization (χ _ARM), saturation isothermal remanence (SIRM)] are observed. The present study shows that these three magnetic parameters can be used as a proxy for Br levels in Xuzhou urban roadside soils.     

Heavy meals in urban roadside soils, part 1: effect of particle size fractions on heavy metals partitioning

Urban roadside soils are important environmental media for assessing heavy metal concentrations in urban environment. However, among other things, heavy metal concentrations are controlled by soil particle grain size fractions. In this study, two roadside sites were chosen within the city of Xuzhou (China) to reflect differences in land use. Bulk soil samples were collected and then divided by particle diameter into five physical size fractions, 500–250, 250–125, 125–74, 74–45, < 45 μm. Concentrations of metals (Ti, Cr, Al, Ga, Pb, Ba, Cd, Co, Cu, Mn, Ni, V, Zn, Mo, As, Sb, Se, Hg, Bi, Ag) were determined for each individual fraction. These metals could be roughly classified into two groups: anthropogenic element (Pb, Ba, Cd, Cu, Zn, Mo, As, Sb, Se, Hg, Bi, Ag) and lithophile element (Ti, Cr, Al, Ga, Co, Mn, Ni, V) in terms of values of enrichment factor. As expected, higher concentrations of anthropogenic heavy metals (Cu, Zn, Mo, As, Hg, Bi, Ag) are observed in the finest particle grain size fraction (i.e. < 45 μm). However, heavy metals Se, Sb and Ba behave independently of selected grain size fractions. From the viewpoint of mass loading, more than 30% of the concentrations for all anthropogenic heavy metals are contributed by the particle grain size fractions of 45–74 μm at site 1 and more than 70% of the concentrations for all heavy metals are contributed by the particle grain size fractions of 45–74 and 74–125 μm at site 2. These results are important for transport of soil-bound heavy metals and pollution control by various remedial options.     

Relationships between heavy metals and iron oxides,fulvic acids,particle size fractions in urban roadside soils

Urban roadside soils are the “recipients” of large amounts of heavy metals from a variety of sources including vehicle emissions, coal burning waste and other activities. The behavior of heavy metals in urban roadside soils depends on the occurrence as well as the total amount. Accordingly, knowledge of the interactions between heavy metals and other constituents in the soil is required to judge their environmental impact. In this study, correlations of heavy metal concentrations (Pb, Zn, Cu, Ag, Se, Ni, Cr and Ba) to iron extracted using dithionite–citrate–bicarbonate (DCB) buffer (Fe_DCB), fulvic acids and particle size fractions were examined from the Xuzhou urban roadside soils. Heavy metals except for Cr and fulvic acids had a positive significant correlation with Fe_DCB, indicating these metals and fulvic acids are principally associated with the surfaces of iron oxides of the soils. Significant positive correlations were also found between the contents of fulvic acids and heavy metals, showing these heavy metals (especially for Cu, Ni and Cr) form stable complexes with fulvic acids. Such finding is of importance with regard to the increased mobilization of heavy metals, e.g., into freshwater ecosystems. Ag, Se and Cr are independent of particle size fractions because of their low concentrations of Ag and Se in the studied soils. Pb, Zn, Cu, Ba and Ag are mainly enriched in the finer soil particles (especially <16 μm).     

贵州西部龙场地区水系沉积物Pt、Pd异常源地球化学示踪的初步研究

以贵州龙场地区水系沉积物中的Pt、Pd异常为研究对象，选择相容性接近的7对元素比值Cr/Ni、Nb/Ta、Pd/Pt、Rb/Cs、Sr/Ba、Th/U和Zr/Hf以及CaO、TFe2O3作为地球化学示踪指标，对龙场地区水系沉积物的物质来源组成进行了示踪探讨。结果表明：（1）龙场地区水系沉积物的物质来源主要为玄武岩风化产物，其中的高含量Pt、Pd是对玄武岩层中Pt、Pd高背景的继承和进一步浓缩富集；（2）根据对分布在灰岩区的水系沉积物物质来源的地球化学示踪研究，推测部分样品的物质来源应为玄武岩和灰岩风化产物；（3）根据对红岩村的水系沉积物物质来源的示踪研究，推断有热液活动和基性－超基性侵入体的物质成分，预测该地区具有一定的找矿远景。     

Correlations between heavy metals and organic carbon extracted by dry oxidation procedure in urban roadside soils

The organic fraction in soils has a significant influence on heavy metal transport. In this study, the organic carbon content was measured by dry oxidation procedure from 21 Xuzhou urban roadside soils to assess the relationships between the concentrations of heavy metals (Pb, Cu, Zn, and Cr) and the amount of organic carbon. The anthropogenic heavy metals (e.g. Pb, Cu, Zn) were strongly correlated with organic carbon (denoted by C_org−c) extracted by dry oxidation while natural heavy metal (e.g. Cr) showed no correlation to the C_org−c. The anthropogenic heavy metals were also strongly correlated with the amount of the total carbon. These results show that the anthropogenic heavy metals are mainly enriched in the organic matter in the Xuzhou urban roadside soils.     

Accumulation and sources of heavy metals in urban topsoils: a case study from the city of Xuzhou, China

The knowledge of the variability, the anthropogenic versus natural origin and corresponding environmental risk for potentially harmful elements in urban topsoils is of importance to assess human impact. The aims of the present study were: (1) to assess the distribution of heavy metals (Sn, Li, Ga, Ba, Fe, Mn, Co, Be, Ti, Al, Hg, Cr, Sb, As, Bi, Pd, Pt, Au, Ni, Cd, Zn, Cu, Pb, Se, Mo, Sc and Ag) in urban environment; (2) to discriminate natural and anthropogenic contributions; and (3) to identify possible sources of pollution. Multivariate statistic approaches (principal component analysis and cluster analysis) were adopted for data treatment, allowing the identification of three main factors controlling the heavy metal variability in Xuzhou urban topsoils. Results demonstrate that Hg, Cr, Sb, As, Bi, Pd, Pt, Au, Ni, Cd, Br, Zn, Cu, S, Pb, Se, Mo, Sc and Ag could be inferred to be tracers of anthropogenic pollution, whereas Al, Ti, Ga, Li, V, Co, Pt, Mn and Be were interpreted to be mainly inherited from parent materials. Iron, Ba, Sn, Pd and Br were interpreted to be affected by mixed sources.     

Correlation between magnetic susceptibility and heavy metals in urban topsoil: a case study from the city of Xuzhou, China

Anthropogenic influence, mainly due to urban and industrial activities and traffic exhaust, may affect urban topsoil via atmospheric contamination and solid waste. Magnetic susceptibility measurements were conducted on 21 urban topsoil samples from the city of Xuzhou, China. High intensities of magnetic susceptibility were detected in the majority of the samples. SEM analysis shows that magnetic minerals are in the form of spherules and mainly due to anthropogenic inputs. The heavy metals Pb, Cu, Zn, Se, Sc, Mo, Fe, and Bi show strong correlations with magnetic susceptibility, and Ag, Ba, Cd, Ni, Cr, Sb, and Sn, on the other hand, show a weak correlation with magnetic susceptibility. Whereas, of these metals studied, only Hg has no significant correlation with the susceptibility. The Tomlinson pollution load index (PLI) also shows significant correlation with the susceptibility (χ). The present study shows that magnetic susceptibility is a fast, inexpensive, and non-destructive method for the detection and mapping of contaminated soils.     

Magnetic properties of urban topsoils and correlation with heavy metals: a case study from the city of Xuzhou, China

Heavy metals in urban topsoils have been shown to be very useful tracers of environmental pollution. Thus, their detailed studies are of great importance. Apart from expensive and time-consuming chemical methods, several simple, rapid and cheap proxy methods have been developed recently, one of them being based on rock-magnetic parameters. This examines the use of rock-magnetic methods designed to assess the degree of heavy-metal pollution of urban topsoils from the city of Xuzhou (China). The aim was to identify the magnetic properties and to link the “magnetic pollution” to the concentrations of the heavy metals. Since a strong correlation has been found between saturation isothermal remanent magnetization (SIRM) and the heavy metals, namely, Fe, Se, Ti, Sc, Ba, Bi, Pb, Cu, Zn, Cr and Mo, an anthropogenic contamination origin is thought to be the cause. The present study shows that SIRM is a fast, inexpensive and non-destructive method for the detection and mapping of heavy-metal-contaminated urban topsoils.     

泡沫塑料富集-电感耦合等离子体质谱法测定土壤中超痕量金铂钯

样品采用王水溶解,二氯化锡还原,泡沫塑料富集,用Re作内标,电感耦合等离子体质谱法同时测定土壤中超痕量金、铂、钯。在盐酸-二氯化锡体系中,盐酸酸度为15%,二氯化锡浓度为45 g/L,吸附时间30 min时吸附效果明显,吸附温度为25℃时吸附率相对稳定。方法检出限Au为0.21 ng/g,Pt为0.18 ng/g,Pd为0.16 ng/g,方法加标回收率Au为91.3%~97.8%,Pt为92.0%~96.7%,Pd为96.0%~101.6%。该方法用于测定国家一级标准物质,线性范围宽、重现性好,结果准确可靠,样品处理简便、快速。     

利用对数正态分布图解析徐州城市土壤中重金属元素来源和确定地球化学背景值

城市土壤指示了城市环境中重金属污染的状况.为了更好地评价人为因素对城市土壤的影响强度,确定城市土壤重金属元素的地球化学背景值是十分必要的.以徐州城市表层土壤中Pb、Cu、Zn、V、Se和Ti等重金属为例,利用对数正态分布图区分了不同元素的来源,其中Ti和V主要来自土壤母质的分化,而Pb、Cu、Zn和Se等的来源则比较复杂,表现为受人为因素作用强烈.这些结果与利用多元统计方法(如聚类分析和主成分分析)获得的结果一致.利用对数正态分布图获得了Pb、Cu、Zn、V、Se和Ti等元素的地球化学背景值.     

香炉山地区水系沉积物铂·钯地球化学异常特征

香炉山地区采用1个样/km²的水系沉积物测量,在苏家营-则家坪地区圈出1个Pt、Pd、Au异常带,异常带明显受NNW向或近SN向构造控制,从异常规模和强度推测苏家营-则家坪Pt、Pd、Au地球化学异常具有找寻铂钯矿的远景.     

TSC大孔螯合树脂对金铂钯的吸附特性及其在岩矿分析中的应用

本文研究了TSC大孔螯合树脂对贵金属Pt(Ⅳ)、Pd(Ⅱ)、Au(Ⅲ)和贱金属Cu(Ⅱ)、Pb(Ⅱ)、Zn(Ⅱ)、Fe(Ⅲ)、Al(Ⅲ)等的吸附特性。测定了树脂在不同酸度下对Au(Ⅲ)、Pt(Ⅳ)、Pd(Ⅱ)的饱和吸附容量。研究结果表明,该树脂可从稀HCl、稀王水溶液中定量吸附Au(Ⅲ)、Pt(Ⅳ)、Pd(Ⅱ),而贱金属离子则不被吸附。吸附在树脂上的Au、Pt、Pd可被5％硫脲溶液洗脱,洗脱液中的Au、Pt、Pd可分别用火焰和无火焰原子吸收法测定。标准加入回收率为97—107％。通过对MGI-Au-07,MCM-02标准样品和其它样品的测定,说明应用本法可获得满意的结果。     

丰山斑岩型铜(钼)矿床中铂、钯的富集特征研究

文章以湖北丰山斑岩型铜(钼)矿床为研究对象,利用ICP-MS分析了Pt、Pd含量,发现丰山斑岩型铜(钼)矿床矿石中Pt、Pd发生了富集现象.其中,Pt含量范围在0.037×10-9～1.765×10-9,Pd含量范围在0.165×10-9～17.979×10-9,Pd含量普遍较Pt含量高出1个数量级,表明丰山斑岩型铜(钼)矿床中Pd较Pt易富集.测试结果表明,斑岩体中Pt、Pd含量很低,说明岩体发生了分异,且Pt、Pd来源与中酸性岩体关系密切.研究发现,Au与Pt、Pd表现出明显的镜像关系,成为丰山宽岩型铜(钼)矿床Pt、Pd富集的特征表现.     

内蒙古渣尔泰山群和白云鄂博群中Pt、Pd地球化学特征及找矿建议

内蒙古渣尔泰山群和白云鄂博群是一套陆源碎屑岩、泥页岩、碳酸盐岩,地层中Pt、Pd的含量与原岩中泥质、有机碳、有机质的含量有关。其中渣尔泰山群中的阿古鲁沟组炭质板岩、增隆昌组硅质炭质板岩为含Pt、Pd最佳层位(岩性),白云鄂博群中的比鲁特组千枚状板岩也为含Pt、Pd的最佳层位(岩性)。通过研究Pt、Pd的富集状况、存在形式、矿物学特征等,可查明渣尔泰山群、白云鄂博群中的含矿层位,以达到寻找铂、钯矿床的目的。     

江苏徐州城市地质调查需求分析及关键问题

随着城市化及城乡一体化进程加快,地质环境问题对城市建设的影响日益突出,开展城市地质调查,解决城市地质问题已成为当务之急。从徐州市城市规划建设、重大工程建设、城市防灾减灾、生态环境保护及"智慧徐州"构建等方面分析徐州城市发展对地质调查工作的需求,从基础地质、地质资源、地质环境、综合研究、信息系统5方面部署徐州城市地质调查工作,并提出徐州城市地质调查中亟需解决的关键问题,即地下水资源约束与应急供水保障、岩溶区地下工程风险与灾害防控、采空区建设用地的适宜性与风险评价、塌陷地复垦土地质量与生态安全、城市地质信息系统的构建与"智慧徐州"融合。     

锍镍试金富集—等离子质谱法测定地质样品中的金铂钯铑铱钌

建立了锍镍试金富集—电感耦合等离子质谱法测定地质样品中金铂钯铑铱钌的方法。研究了富集时各种实验因素的影响,样品用琉试金富集,盐酸处理锍镍扣,碲共沉淀富集,过滤,沉淀用王水溶解,ICP-M S测定。方法检出限:A u为0.11、P t为0.050、Pd为0.028、R h为0.018、Ir为0.013、R u为0.02,相对标准偏差(n=12),A u为8.25%、P t为4.76%、P t为4.97%、R h为5.63%、Ir为5.38%、R u为6.81%。经国家一级地球化学标准物质验证,铂族元素和金的测定值与标准质相吻合。     

Assessment of heavy metals contamination in urban topsoil from Changchun City,China

Due to the rapid urbanization and industrialization that has occurred in China over the last few decades, metals have been continuously emitted into the urban environment and now pose a serious threat to human health. Indeed, there is a growing concern over the potential for pollution of urban soils with heavy metals. Therefore, an extensive soil survey was conducted in urban areas of Changchun, China, to evaluate the current status of heavy metal contamination in soils and to evaluate its potential sources. A total of 352 samples of urban soils were collected from urban areas of Changchun using a systematic sampling strategy in which one sample per km² was taken (0 ~ 20 cm). The levels of Cu, Pb, Zn and the major elements (Mn, Al₂O₃, CaO, Fe₂O₃, MgO, SiO₂, K₂O and NaO) were then determined by X-Ray fluorescence spectrometry (XRF), while the level of Cd was determined by graphite furnace atomic absorption spectrometry (GF-AAS), and the Hg and As concentrations were determined by atomic fluorescence spectroscopy (AFS). The results indicated that, when compared with the background values of topsoil in the Changchun region, the topsoil in urban areas were enriched with metals, particularly Cu, Cd, Zn, Pb and Hg. The results of correlation coefficient analysis showed that Hg, As, Cd, Cu, Pb and Zn were significantly positive correlated with each other, while Cr and Mn formed another group. Moreover, significantly positive correlations were observed between pH and Zn, Pb, Cu, Cd, As and Hg, indicating that pH influences the distributions of these metals in urban soils in Changchun. Principal component analysis (PCA) was conducted to identify sources of heavy metals and the results revealed distinctly different associations among the trace metals and the major elements in the urban soils. The concentration of Cr appeared to be controlled by the parent material (natural sources), while Cu, Pb and Zn were mainly from vehicle emissions, with Zn primarily coming from vehicle tires. Additionally, Hg and As primarily originated from coal combustion, while Cd was mainly associated with industrial sources. According to the pollution index (PI) of each metal, the overall levels of metal pollution were not especially high, but there were clearly contaminated sites concentrated in the central and northeast portion of the studied region. The Nemerow integrated pollution index (NIPI) of the seven metals also indicated that urban soils in Changchun city were classified as having low level of pollution.     

Heavy metals in Xuzhou urban roadside topsoils (China): magnetic characterization and enrichment mechanism

Heavy metal contamination is prevalent in urban areas where soil represents a significant sink. Urban topsoil samples were collected and metal concentrations including Pb, Zn, Cu, Cd, Ni and Co were measured by inductively coupled plasma mass spectrometry. All analyzed metals showed elevated concentrations compared to local background concentrations with the exception of Co. Cadmium was the metal most enriched in the analyzed area, presenting enrichment factor, on average, of 16.5. Mineral magnetic concentration parameters (χlf and SIRM) exhibited significant relationships with Pb, Zn, Cu and Cd, respectively. Zinc, Co and Ni exhibited a substantial build-up in the finest particles (<28 μm). Enrichment was positively correlated with carbonate complexation constants (but not bulk solubility products) and suggests that the dominant mechanism controlling metal enrichment in these samples is a precipitation of carbonate surfaces that subsequently adsorb metals.     

长江口及邻近陆架沉积物中Pt、Pd分异的物源示踪

Pt/Pd比值在研究区分布呈显著的区域特征.南黄海沿岸流输送物质以Pt/Pd > 1为特征, 为古黄河三角洲来源; 长江流域来源物质以Pt/Pd≤1为特征.长江物源组分的影响范围广, 在125°E、33°N沉积物中还能发现受长江物质的明显影响.除了源岩中Pt、Pd分配因素外, 黄河和长江流域不同类型和程度的风化作用对沉积物中Pt、Pd分异起着关键的控制作用.虽然沉积物中氯含量、粒度效应在一定程度上影响着Pt、Pd分布, 但是没有造成显著的Pt、Pd分馏.Pt/Pd≤1区域中元素组成和长江沉积物的组成特征一致, 呈现比较强的硅质风化作用; Pt/Pd > 1区域沉积物中的元素组成和黄河沉积物一致, K/Na-Rb/Sr图解显示古黄河物质在再侵蚀、搬运和沉积过程中化学成分进一步分异.