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1.
北京市街道灰尘中重金属元素赋存状态及环境效应   总被引：5，自引：3，他引：2  
刘春华  岑况  于扬 《岩矿测试》2011,30(2):205-209
采用Tessier的五步提取法,对北京北西—南东剖面所采集的街道灰尘样品粒度≤100μm组分中As、Cd、Cr、Hg、Pb和Zn等6元素的5个形态(可交换态、碳酸盐结合态、铁锰氧化物结合态、有机物结合态、残渣态)的分布特征研究发现,在可交换态和碳酸盐结合态中Cd的含量比都为最高,Pb、Hg、Zn和As在有机物结合态中含量比相近,铁锰氧化物结合态中Pb所占比例最高,而As和Cr主要存在于残渣态中。6种街道灰尘污染元素的相对活动性和潜在生物利用度顺序为:Cd>Zn>Pb>Cr>Hg>As。  相似文献   

2.
Sequential core sediments from northwestern Taihu Lake in China were analyzed for grain size, organic carbon and heavy metal content. The sediments are composed of organic-poor clayey-fine silts. The chemical speciations of Cu, Fe, Mn, Ni, Pb, and Zn were also analyzed using the BCR sequential extraction procedure. Cu, Fe, Ni, and Zn are mainly associated with the residue fraction; Mn is concentrated mainly in exchangeable/carbonate fraction and residue fraction; and Pb mainly in Fe/Mn oxide fraction and organic/sulfide fraction. The exchangeable/carbonate fractions of Cu, Fe, Ni, Zn and Pb are lower. The fractions of Ni, Pb and Zn bound to the Fe/Mn oxide have significant correlations with reducible Mn; the organic/sulfide fractions of Cu, Mn, Ni, Pb, and Zn have significant correlations with TOC. The extractable fractions of Cu, Mn, Ni, Pb, and Zn are high at the top 4 cm of the core sediments as compared to those in the deeper layers, showing the anthropogenic input of heavy metals is due to rapid industrial development. The heavy metal pollution history of the sediments has been recorded since the late 1970s, determined by the result of ^137Cs dating.  相似文献   

3.
Consideration of the impact of substantial changes in soil temperature or moisture regime on the geochemical forms of radionuclides is important for more accurate assessment of the environmental risk posed by radionuclide migration and potential biological availability, especially in the first months after their release into the environment. This paper presents the results from a study of the influence of cooling, freezing and soil drought on the migration and potential bioavailability of 60Co and 137Cs in two soils (a fluvisol and a cambisol, according to the World Reference Base for Soil Resources/FAO) from Bulgaria. The changes in the geochemical fractionation of 60Co, the exchangeable 137Cs and water-soluble forms of both radionuclides were examined under different storage conditions up to 5 months after their introduction into the soils in solution form. Freezing or soil drought resulted in a significant increase of the water-soluble forms of 60Co in the fluvisol soil, defining higher mobility and potential bioavailability. No influence of the storing conditions on the water-solubility of 60Co in the cambisol soil was established. The cooling, freezing and soil drought caused an increase of the exchangeable 137Cs in both soils.  相似文献   

4.
以珠江三角洲平原为研究区域,对其7个区县102件水稻根系土样品进行土壤理化参数及Pb形态分析,探讨在第四系分布区土壤Pb全量及Pb活动态含量的特征及影响因素。结果表明:全部供试土壤样品中Pb元素平均含量为46.47mg/kg,略高于广东省土壤Pb含量背景值(36mg/kg),表现出一定的累积趋势。研究区自西北陆相沉积区至南部海陆交互相沉积区,元素含量增高。Pb元素主要以残渣态和铁锰氧化物形态赋存在土壤中,迁移能力弱。影响土壤Pb全量的因素主要有Al2O3、K2O、Tl、Mo;影响土壤Pb活动态的因素有Pb全量、pH、有机质、CEC、P、TFe2O3、Mn;其中,p H是控制Pb元素活动性的最主要因素。  相似文献   

5.
Soils from historical Pb mining and smelting areas in Derbyshire, England have been analysed by a 5-step sequential extraction procedure, with multielement determination on extraction solutions at each step by ICP-AES. Each of the chemical fractions is operationally defined as: (i) exchangeable; (ii) bound to carbonates or specifically adsorbed; (iii) bound to Fe–Mn oxides; (iv) bound to organic matter and sulphides; (v) residual. The precision was estimated to be about 5%, and the overall recovery rates were between 85 and 110%. The carbonate/specifically adsorbed and Fe–Mn oxide phases are the largest fractions for Pb in soils contaminated by both mining and smelting. Most of the Zn is associated with Fe–Mn oxide and the residual fractions. Cadmium is concentrated in the first 3 extraction steps, particularly in the exchangeable phase. The most marked difference found between soils from the mining and smelting sites is the much higher concentrations and proportions of metals in the exchangeable fraction at the latter sites. This indicates greater mobility and potential bioavailability of Pb, Zn and Cd in soils at the smelting sites than in those in the mining area. The most important fraction for Fe and Al is the residual phase, followed by the Fe–Mn oxide forms. In contrast, the Fe–Mn oxide fraction is the dominant phase for Mn in these soils. In the mining area, most of the Ca is in the carbonate fraction (CaCO3), while the exchangeable and residual phases are the main fractions for Ca at the smelting sites. Phosphorus is mainly in the residual and organic fractions in both areas. The exchangeable fractions of Pb, Zn and Cd in soils were found to be significantly related to the concentrations of these metals in pasture herbage.  相似文献   

6.
对拜仁达坝铅锌矿矿集区3个多金属矿区的3个土壤粒级样品中Zn、Pb、Cu、Ag 4种主要成矿元素的7种赋存形式(水溶态、离子交换态、碳酸盐结合态、有机质结合态、铁锰氧化物结合态、硫化物结合态和残渣态)进行了测定。研究结果表明:1银都矿区土壤中Zn、Pb和Ag浓度最高,而道伦达坝矿区土壤中Cu的浓度最高;2拜仁达坝矿集区土壤中Zn、Pb和Cu主要以残渣态形式赋存,而Ag主要以铁锰氧化物结合态和硫化物结合态形式赋存;3拜仁达坝矿集区Zn、Pb和Cu元素在3个土壤粒级中的各个赋存形式所占的比例略有差别,但总体上大致相同,而Ag元素的赋存状态在3个土壤粒级的差异较大;4 3个矿区土壤中水溶态、离子交换态、碳酸盐结合态和有机质结合态的Zn和Pb差别不大;铁锰氧化物结合态、硫化物结合态和残渣态的Zn和Pb,以及Cu和Ag的7个赋存状态在3个矿区的差别较大。  相似文献   

7.
Sediment samples were collected from six springs draining the karst aquifer at Fort Campbell, Kentucky/Tennessee. These were analyzed by ICP-MS following an extraction procedure that separates the metals into exchangeable, carbonate, oxide, organic and residual fractions. Aluminum and iron are primarily present in the residual fraction while manganese may be dominantly in either the oxide or carbonate fraction. The redox-sensitive metals (Fe and Mn) have the greatest fractional distribution in the spring with the thickest sediments. Trace metals detected include Cr, Cd, Ni, Pb, and Zn in the range of a few to 200 mg/kg. In Beaver Spring, nickel is distributed between the exchangeable, carbonate and organic fractions, while in Gordon Spring, nickel is largely residual. Chromium is almost entirely associated with the organic fraction in Beaver Spring while it is largely residual in Gordon Spring.  相似文献   

8.
煤矸石地表堆积是我国东部煤矿区生态环境破坏的典型形式,造成堆积区土壤重金属污染的防控已成为当前研究热点。以河北峰峰矿区某在用煤矸石山周边(方圆300 m以内)浅层土壤(垂直深度40 cm以浅)为研究对象,采用Tessier连续提取法和电感耦合等离子体发射光谱仪,测定Cu、Cr、As、Pb这4种土壤重金属的有效态、铁(锰)氧化物结合态、有机结合态和残渣态含量,基于生物活性系数(MF)和生态风险评价编码法(RAC)计算与评价4种土壤重金属生物有效性及生态风险,剖析4种土壤重金属形态组成与生物有效性的空间变化特征。结果表明:(1) 煤矸石的堆存具有提高周围土壤中Cu、Cr、As、Pb有效态质量分数和降低残渣态质量分数的效应,且与距煤矸石山的水平距离成反比,当水平距离达到或接近300 m时,该效应基本消失。(2) 土壤总有机碳(TOC)质量分数与4种重金属有效态质量分数的相关系数均超过0.6,达到显著正相关水平(p<0.05),是影响研究区土壤重金属有效态含量空间变化特征的主要因素。(3) 4种土壤重金属生物有效性的空间变化特征可分为2个类型,Ⅰ类为“MF值一般大于3,且具有显著的空间异质性”;如 Cu、Cr,Ⅱ类为“MF值一般小于3,且具有显著的空间同质性” ,如As、Pb。(4) 当距煤矸石山水平距离分别小于80和40 m时,土壤重金属Cu、Cr的 MF平均值超过中等风险水平阈值的60%,应予以重视。建议综合考虑煤矸石山存续状态、土壤重金属累积效应及生物有效性空间变化特征等因素,制定煤矸石堆积区土壤重金属污染精准防控及安全利用策略。   相似文献   

9.
Total concentrations of chemical elements in soils may not be enough to understand the mobility and bioavailability of the elements. It is important to characterise the degree of association of chemical elements in different physical and chemical phases of soil. Another geochemical characterisation methodology is to apply sequential selective chemical extraction techniques. A seven-step sequential extraction procedure was used to investigate the mobility and retention behaviour of Al, Fe, Mn, Cu, Zn, Pb, Cr, Co, Ni, Mo, Cd, Bi, Sn, W, Ag, As and U in specific physical–chemical and mineral phases in mine tailings and soils in the surroundings of the abandoned Ervedosa mine. The soil geochemical data show anomalies associated with mineralised veins or influenced by mining. Beyond the tailings, the highest recorded concentrations for most elements are in soils situated in mineralised areas or under the influence of tailings. The application of principal components analysis allowed recognition of (a) element associations according to their geochemical behaviour and (b) distinction between samples representing local geochemical background and samples representing contamination. Some metal cations (Mn, Cd, Cu, Zn, Co, Cr, Ni) showed important enrichment in the most mobilisable and bioavailable (i.e., water-soluble and exchangeable) fractions due likely to the acidic conditions in the area. In contrast, oxy-anions such as Mo and As showed lower mobility because of adsorption to Fe oxy-hydroxides. The residual fraction comprised largest proportions of Sn and Al and to a lesser extent Zn, Pb, Ni, Cr, Bi, W, and Ag, which are also present at low concentrations in the bioavailable fractions. The elements in secondary mineral phases (mainly Fe, Mn, Cu, Zn, Cd, Pb, W, Bi, Mo, Cr, Ni, Co, As and U) as well as in organic matter and sulphides are temporarily withheld, suggesting that they may be released to the environment by changes in physico-chemical conditions.  相似文献   

10.
《Applied Geochemistry》1996,11(3):409-423
Determining metal bioavailability is critical in assessing the necessity to remediate contaminated sediments. In the Halls Brook Holding Area Pond (HBHAP) sapropel, As (3000 mg/kg), and Cr (1400 mg/ kg), are sequestered by amorphous Fe(OH)3 (KdAs=560; KfCr=59,0001/kg), while Pb solubility is limited by PbS(am). Fillet As concentrations in detritivorous and omnivorous fish were similar in the HBHAP (1.19 mg/kg), and the adjacent unimpacted Phillips Pond (1.18 mg/kg). Cr and Pb in both HBHAP and Phillips Pond fish were below analytical detection limits, except for one (0.73 mg/kj Pb), in the HBHAP. The low sediment bioaccumulation factors for As, Cr, and Pb (6.5 × 10−4, < 1.1 × 10, and 1.8 × 10−6, respectively in HBHAP) suggest that the sediment acts to sequester metals, rendering them non-bioavailable due to precipitation of solids, and sorption to iron phases.  相似文献   

11.
In this paper the seven-step continuous extracting method was employed in the study of chemical forms of the six heavy metals Co,Zn,Pb,Cu,Cr and Mn,The result shows that the etals in the laterite are present in the chemical form of crystalline iron oxides and residues,and they are transformed towared organic and exchangeable forms in the surface soil.Linear regression analysis indicates that the above heavy metals have a positive correlation with the crystalline iron oxide minerals.The crystalline iron oxide minerals have a very important role to play in the enrichment of heavy metals,especially the solid components in the laterite.  相似文献   

12.
土壤中重金属有效态分析方法研究   总被引：2，自引：0，他引：2  
土壤中重金属的不同形态决定了对于生物的有效性。自然界的重金属元素参与生态迁移能够被生物吸收利用的部分为生物有效态。土壤重金属可交换态的研究可以为其生物有效态研究提供参考。本文对于土壤中砷、汞、铬、镉、铅和铊的酸溶态、络合态和盐溶态这几种单一提取方式的可交换态的分析方法进行了研究比较,以其提取效率高的为有效态的表现方式,以p H值7.5为土壤酸碱度的界限,建立了土壤中的砷、汞、铬、镉、铅和铊在不同酸碱度下的分析方法。本方法的Cr的方法检出限为4.65ng/g;Cd的方法检出限为0.49ng/g;Pb的方法检出限为9.73ng/g;As的方法检出限为21.89ng/g;Hg的方法检出限为0.30ng/g;Tl的方法检出限为0.54ng/g。采用GBW7412,GBW7413,GBW7416这三个国家一级标准物质样品测得的方法精密度范围6.01%~19.3%。本方法适用于土地质量评估的要求。  相似文献   

13.
The speciation of metals in environmental samples is a critical factor in assessing the potential environmental impacts, before their disposal. The distribution and speciation of toxic heavy metals in plating wastewater residues and sludge was investigated for four samples using sequential extraction method. Tessier method was used to fractionate the metal content into exchangeable, acid extractable, reducible and oxidizable fractions. Residual and total metal contents were determined in aqua regia digest. The extracts were analysed for metals using inductively coupled plasma -atomic emission spectrometry. The bioavailable fraction (exchangeable and acid extractable fractions) is comprised less than the other forms. The oxidisable and reducible forms are dominants for all the four samples studied. The major metal constitute in the samples is iron, the wastewater residue contains (12.3 and 7.4 g/Kg respectively on dry basis) and the sludge contains (31.5 and 41.6 g /Kg) respectively. Cr concentration is higher in wastewater residue of second electroplating industry. The descending order of the average total metal contents for these four samples were Fe > Cr > Sn > Zn >Cu > Ni > Mn > Pb > Cd > Ag. Based on the average of absolute values for the four samples the highest bioavailability order of metals is Cr (39 %) in wastewater residues and Zn (32 %) in sludge samples. Metal recovery was good, with < 10 % difference between the total metal recovered through the extractant steps and the total metal determined using aqua regia extract.  相似文献   

14.
吉林西部土壤铁形态分布及其与土壤性质的关系研究   总被引：1，自引：0，他引：1  
对吉林西部三个主要农牧区(洮南市、通榆县和乾安县)50个表层土样进行测试,探究其土壤铁形态分布及其与土壤性质的关系。研究结果表明,其土壤铁形态的含量分布为:残渣态铁(A)铁锰结合态铁(B)腐植酸结合态铁(C)碳酸盐态铁(D)强有机结合态铁(E)水溶态铁(F)离子交换态铁(G),主要以A形式存在,且全铁平均含量均低于中国铁元素背景值。A与阳离子交换量(CEC)呈极显著正相关,B与p H值呈极显著正相关,C、E与有机质呈极显著正相关。A与土壤矿质元素的关系最为密切,C、D、G次之。各形态铁之间,B、C、D两两呈极显著正相关,其他形态铁彼此间关系不大。  相似文献   

15.
Dianshan Lake is one of the important water supply sources for Shanghai City. The contents of heavy metals in the sediments are obviously higher than those in the overlying water body. The contents of Pb in the sediments vary seasonally; with increasing depth, the contents of Cd, Pb, Cu, Cr and Fe show no variation generally, but Mn varies in the peak pattern. Cd, Pb, Cu, Cr and Fe in the sediments are present predominantly in sludge phase, but iron and manganese oxide form of Pb and organic matter-sulfide form of Cu are their respective preferential combining forms. Manganese is present largely in exchangeable form, iron-manganese oxide combined form and sludge form. The contents of the various forms of Cd, Pb, Cu, Cr and Fe tend to vary with changing season and depth. The contents of exchangeable forms of Fe and Mn vary with depth in the peak-like pattern.  相似文献   

16.
《Applied Geochemistry》2003,18(11):1723-1731
The mobility and bioavailability of heavy metals depends on the metal retention capacity of soil and also on the geochemical phases with which metals are associated. Laboratory batch experiments were carried out to study the sorption and distribution of Cd, Ni and Pb in 3 soils differing in their physicochemical properties from India: Oxyaquic Haplustalf (SL1), Typic Haplustalf (SL2) and Typic Haplustert (SL3). The heavy metal adsorption was studied by isotherms and the distribution coefficient (KD) for each metal was obtained from the linear regressions of the concentration of metal remaining in equilibrium solution and the amount adsorbed. In general, the sorption capacity for all the metals decreased in the order: SL3>SL2>SL1. Among metals, the sorption capacity in all the soils decreased in the order: Pb>>Ni>Cd. Distribution of sorbed metals at various equilibrating concentrations was studied by sequential extraction. Results showed significant differences in the distribution of metals in these soils. At higher additions (such as 200 μM l−1) most of the metals were extracted in their more mobile fractions, exchangeable and/or inorganic in contrast to their original partitioning in soils, where they were preferentially associated with the less mobile residual fraction. Largest percentages of metals extracted in the exchangeable fraction corresponded to those soil–metal systems with smaller KD values, e.g. Cd, Ni and Pb in SL1 and Cd and Ni in SL2. In neutral and alkaline soils (SL2, pH=7.1, and SL3, pH=8.6) Pb was predominantly extracted from the inorganic fractions and this corresponded to higher KD values for Pb in these soils. The predominance of metals associated with the exchangeable fraction together with low KD values indicates higher mobility of metals retained in the acidic soil (SL1, pH=5.2) compared with the others.  相似文献   

17.
按Tessier连续浸提法对德安锑矿区土壤样品进行了分析,得出锑的存在状态主要以残渣态为主,其次是Fe/Mn结合态,有机/硫化物结合态和碳酸盐结合态,可交换态和水溶态占的比率最小。矿区土壤中锑生物可利用态锑占0.52%~3.51%,其浓度一般在1.78~17.48μg/g,中等可利用态占1.04%~5.56%,生物难利用态锑的浓度占92.1%~98.4%。  相似文献   

18.
《Applied Geochemistry》1998,13(4):415-420
The European Communities Bureau of Reference (BCR) and Chunguo sequential extraction procedures were employed to evaluate the retention of U and As by a soil contaminated with low level radioactive waste. Modifications were made to both procedures to optimize the measurement of soil and extractant samples using epithermal neutron activation analysis. Based on the BCR procedure, approximately 20% of the U appeared to be bound to the carbonate fraction, 10% to the mineral oxide fraction and 20% to the organic fraction. In the case of As, the majority was strongly bound in the residue fraction. The results obtained with the Chunguo procedure supported these conclusions to some extent, in that the majority of the U and As was found to be strongly bound to the soil in a manner consistent with its presence in the residue fraction.  相似文献   

19.
Toxicity of heavy metals adversely affects environment and human health. Organic materials derived from natural matters or wastes have been applied to soils to reduce the mobility of contaminants such as heavy metals. However, the application of cow bone powder (CB), biochar (BC), and eggshell powder (ES) is rarely investigated for the reduction of Pb bioavailability in soils irrigated with saline water. The objective of this study was to assess the effectiveness of CB, BC, and ES additions as immobilizing substances on Pb bioavailability in shooting range soil irrigated with deionized and saline water. Each additive of CB, BC, and ES at 5 % (w/w) was mixed with soils and then the deionized and saline water were irrigated for 21 days. With deionized water irrigation, the soils treated with CB, BC, and ES exhibited higher pH when compared with saline water irrigation. With saline water irrigation, the electrical conductivity, water-soluble anions, and cations were significantly increased in soils treated with CB, BC, and ES. The water-soluble Pb in soils treated with CB, BC, and ES was significantly decreased with saline water irrigation. On the other hand, the water-soluble Pb in soil treated with CB was increased with deionized water irrigation. Only BC with saline water irrigation decreased the Pb concentration in maize shoots.  相似文献   

20.
矿产品堆场土壤中重金属在环境中富集,随着元素的迁移、转化及地下水的循环,成为环境污染问题。本文将改进的顺序提取法(BCR)应用于矿产品堆场土壤中Cd、As、Pb的化学形态分析,结合这三种元素的性质,将堆场土壤中Cd、As、Pb分为可交换态、可还原态、可氧化态和残渣态,并利用电感耦合等离子体发射光谱法测定其含量。采用形态分析标准参考物质GBW 07436验证了三步提取态的准确性,并对6个矿产品堆场土壤中Cd、As、Pb形态含量进行分析,三步提取态加上残渣态质量分数之和与重金属总量进行了比较,回收率为85.54%~102.88%。通过对矿产品堆场土壤实际样品分析,Cd、As、Pb三种元素非残渣态含量顺序为Cd(79.40%~94.94%)Pb(24.27%~37.73%)As(22.89%~31.51%),表明Cd元素较为容易进入生物圈。该方法解决了港口堆场土壤中重金属化学形态提取问题,对污染土壤的治理具有指导意义。  相似文献   

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