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1.
采用Tessier五步连续提取法和红外光谱技术,研究类芽孢杆菌对铜陵新桥矿区重金属污染土壤中Cu化学形态的影响,初步探讨了Cu形态变化的机理。结果表明,不同投入量的类芽孢杆菌接种到土壤培养一周后,土壤溶液pH值降低,土壤中可交换态、有机结合态Cu含量增加,碳酸盐结合态、铁锰氧化物结合态和残渣态Cu的含量降低。土壤中可交换态、铁锰氧化物结合态和残渣态Cu含量的变化主要受土壤溶液的pH值控制;有机结合态升高主要与类芽孢杆菌菌数及其代谢产生的低分子量有机酸有关。类芽孢杆菌可以改变矿区土壤中Cu的化学形态,影响Cu的生物有效性。 相似文献
2.
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
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
3.
不同茶园茶叶氟含量及土壤氟的形态分布 总被引：7，自引：0，他引：7
通过对我国中西南产茶区12个茶园土壤样品和茶叶样品的采集,探讨了不同茶园茶叶氟含量和茶园土壤氟的形态分布规律。老叶和嫩叶氟含量分别为221～1 504 mg/kg和49.0～602 mg/kg,老叶氟含量是嫩叶的2.5～8.1倍。各形态氟含量随土壤层次加深没有统一变化规律,但各层土壤不同形态氟含量均为残渣态铁锰氧化物态＞有机结合态＞水溶态＞交换态。土壤pH值、有机质含量和阳离子交换量对茶园土壤氟的形态分布有不同程度的影响。老叶和嫩叶氟含量随水溶态氟含量的增加均呈显著增加趋势,但与其他形态氟含量没有显著的相关关系。 相似文献
4.
土壤pH对镉存在形态影响的模拟实验研究 总被引：40，自引：4，他引：36
通过模拟实验,研究了土壤pH对水稻土、紫色土和黄壤的水溶态、可交换态、碳酸盐态、铁锰氧化态、有机结合态和残渣态Cd含量的影响。结果表明:在中碱性条件下,水溶态Cd质量分数比值小于3%,但pH<6.5时,水溶态Cd含量随着pH 减小迅速增加, pH 为4. 57 时,水稻土水溶态Cd 质量分数比值最高达48 39%;可交换态Cd含量在碱性条件下,随着土壤pH值增大迅速下降,在酸性区域内,可交换态Cd含量随pH增加呈上升趋势;碳酸盐态和铁锰氧化态Cd含量随土壤pH增大而增加;有机结合态Cd含量随土壤pH增加而增大,但变化幅度不大。对Cd污染的土壤进行治理时,控制土壤pH大于6.5以及增施有机肥等是减少Cd对生态系统危害的关键。 相似文献
5.
6.
北京城区土壤中Hg、Pb、Cd、Cu及Zn化学形态及环境效应 总被引：1，自引：0，他引：1
为弄清北京城区土壤中Hg、Pb、Cd、Cu及Zn五种重金属元素的化学形态分布特征,系统采集了126件城区表层土壤样品,采用连续提取法对重金属元素各化学形态含量进行了测定。结果表明:土壤中土壤中Hg、Pb、Cd、Cu、Zn含量差异显著。Hg元素以残渣态和强有机结合态为主,Cd元素离子交换态、碳酸盐结合态、残渣态、铁锰氧化物结合态含量较高,Pb、Cu、Zn元素以残渣态、铁锰氧化物结合态为主。Hg元素的有效态含量最低(不足1%),现情况下不会对环境造成污染;Cd元素的有效态含量最高(40%),生物有效性和潜在生态危害性较大,运用植物修复技术对其治理为经济有效的方法;Pb、Cu、Zn有效态含量较低(约10%),生物有效性和潜在生态危害性均有限。各元素形态与全量之间相关程度虽有差别,但基本呈正相关关系。 相似文献
7.
岩溶区典型石灰土Cd形态指示意义及风险评价——以桂林毛村为例 总被引：1，自引：0，他引：1
为了了解岩溶区石灰土中重金属Cd形态分配特征及富集情况,在桂林毛村采集了3种处于不同发育阶段的黑色、棕色和红色石灰土进行研究。通过原子光谱仪测试了Cd质量分数,运用改进的Tessier分析法测定了3种石灰土中Cd的可交换态(EXC)、碳酸盐结合态(CAB)、铁锰氧化物结合态(OXI)、有机结合态(ORG)、残渣态(RES)5种形态,并对其指示意义及风险进行了分析与评价,结果表明,3种石灰土中Cd质量分数从大到小依次为早期黑色石灰土、中期棕色石灰土、晚期红色石灰土。形态测试结果表明:黑色石灰土和棕色石灰土中Cd形态以铁锰氧化态和残渣态为主,占土壤Cd质量分数的63%以上,且5种形态质量分数从大到小顺序均为铁锰氧化态、残渣态、可交换态、碳酸盐结合态、有机结合态;红色石灰土Cd形态以残渣态为主,占土壤Cd质量分数的76%,形态分配特征从大到小为残渣态、铁锰氧化态、可交换态、碳酸盐结合态、有机结合态。Cd稳定度和富集程度评价结果表明:在黑色石灰土、棕色石灰土和红色石灰土中Cd稳定度逐渐减小,环境二次释放风险逐渐降低;富集程度从大到小依次为黑色石灰土、棕色石灰土、红色石灰土,其中Cd在黑色石灰土中呈显著富集状态,在棕色石灰土中呈中度富集状态,在红色石灰土中呈轻微富集状态。潜在生态风险评价和健康风险评价结果表明,由早期黑色石灰土到中期棕色石灰土和晚期红色石灰土,土壤中Cd的生态风险和健康风险均逐渐降低。研究结果可为岩溶区土壤重金属Cd污染修复与治理提供基础数据。 相似文献
8.
岩溶区与非岩溶区不同土地利用方式下土壤Zn元素形态分析 总被引：3，自引：0，他引：3
本文采用连续提取法,对岩溶区与非岩溶区农田和林地两种土地利用形式下土壤中Zn元素形态进行了分级提取。测定结果表明,土壤中Zn元素主要以残渣态(占总量68. 5%～ 85. 0% )存在。此外,岩溶区农田、林地石灰土中Zn元素相对活泼态,即离子交换态(包括水溶态)、碳酸盐结合态、腐殖酸结合态(松结有机结合态)的含量均比非岩溶区对应的要低,而相对稳定态,即铁锰氧化物结合态、强有机结合态(包括部分硫化物态)的含量均比非岩溶区相对应的要高,残渣态含量与相对稳定态具有相同的趋势。这意味着岩溶土壤地球化学环境对土壤Zn的迁移、富集、形态转换具有明显的影响。长期耕种下岩溶区和非岩溶区土壤均会出现缺Zn状况,岩溶区情况更为严重。而适宜的土壤改良措施,可望提高土壤有效Zn形态的含量。 相似文献
9.
文章以桂林典型岩溶区和非岩溶区土壤剖面为研究对象,采用改进的Tessier元素形态连续提取法,测定岩溶区和非岩溶区土壤钙（Ca）和镁（Mg）元素离子交换态（包括水溶态）、碳酸盐结合态、腐殖酸结合态、铁锰氧化物结合态、强有机质结合态（包括部分硫化物）和残渣态等形态,探讨岩溶区和非岩溶区土壤Ca、Mg形态在土壤剖面中的迁移变化特征。结果表明:（1）岩溶区石灰土剖面中,随剖面深度加深,pH值增大,而土壤有机质、全氮（N）、全磷（P）含量减少,Ca元素主要以交换态存在且在各土壤剖面中含量相近,Mg元素主要是以残渣态赋存在土壤剖面中,随着土壤剖面深度腐殖酸结合态百分比减少,存在累积现象;（2）在非岩溶地区酸性土壤中,土壤总钙较低。在土壤剖面0~60 cm以强有机结合态为主,深层剖面（大于60 cm）以残渣态为主;Mg元素有效态含量较低,非岩溶区土壤Mg元素以腐殖酸结合态和残渣态为主,与岩溶区土壤类似,非岩溶区Mg元素在土壤中也存在一定累积。 相似文献
10.
印染污泥中重金属形态分析及生物有效性 总被引：7，自引：2，他引：5
选取上海某印染厂的印染废水处理后的活性污泥样品,通过盆栽土培试验,用黑麦草对印染污泥进行修复,运用Tessier A连续提取法研究修复后黑麦草根际和非根际印染污泥中铅、铜、镍、锌、镉5种重金属形态的变化,以及重金属的生物有效性与植物中有效态含量之间的关系。结果表明,栽培后根际与非根际环境中各重金属元素具有典型的形态分布特征:铅主要以离子交换态和残渣态存在;铜主要以碳酸盐结合态和残渣态存在;镍由紧结合态(铁锰氧化物结合态+有机结合态)向离子交换态转移;锌的有机结合态和碳酸盐结合态有所增加;镉主要以离子交换态和铁锰氧化物结合态为主,说明镉元素较活泼,具有潜在的环境影响能力,应该给予更多的关注。印染污泥中重金属的生物有效性与重金属元素的性质有关,铜、锌的生物有效性较高,其次是铅,最低是镍、镉。 相似文献
11.
恬矿库周围土壤中重金属存在形态特征研究 总被引：48，自引：4，他引：44
通过对大冶铜绿山铜铁矿尾矿库周围土壤中重金属形态分析实验,研究了重金属各种形态在土壤中的分布特征。由对比实验可知,尾矿库周围土壤中Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ等重金属含量都显著地高于对照样品,书经受到重金属的严重污染。土壤中重金属形态分布征为：ｗ（Ｃｒ、Ｚｎ、Ｆｅ）;可变换态〈碳酸盐态〈有机态〈铁锰氧化态〈残渣态;ｗ（Ｃｕ、Ｐｂ）：可变换态〈碳酸盐态〈有机态〈残渣态〈铁锰氧化态;ｗ（Ｃｄ）：残渣态,有机 相似文献
12.
Chemical partitioning of trace and major elements in soils contaminated by mining and smelting activities 总被引：4，自引：0，他引：4
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
13.
G. Guo T. Yuan Ph.D. W. Wang Ph.D. D. Li J. Wang 《International Journal of Environmental Science and Technology》2011,8(4):715-722
The bioavailability of copper in contaminated soils has received more attention due to the safety concern of food chain. The bioavailability of metals is determined by its fractions which are affected by the soil properties and its aging time. This paper focused on the aging effect on the bioavailability of copper added to the soil. The garden soil (fluvo aquic soil) was treated with 100 mg/kg and 1000 mg/kg of copper(II) sulfate and incubated for 14, 21, 28, 42, 63, 120, 200, 300 and 400 days in the laboratory respectively. The sequential extraction procedure was used to characterize copper bioavailability in the soil. Meanwhile, the barley was cultured on the same soil incubated and its toxicity was assessed according to the guideline of International Organization for Standardization. The findings show that the exchangeable and carbonate-bound copper decreased with the aging time after addition of copper(II) sulfate to soil. Meanwhile, the percentages of Fe-Mn oxides- and organic-bound copper increased. The residual copper was changed little during the aging course. The copper fractions became stable in soils after 60 days. The kinetic equations showed that the Power function and the Elovich equation were well fitted to the experimental data, and the r2 values ranged from 0.840 to 0.982 and 0.741 to 0.975, respectively. The barley test showed that the barley root length was more sensitive to reflect copper toxicity than the shoot biomass, and the exchangeable and carbonate-bound copper were significantly correlated with the barley root length. 相似文献
14.
硒是人体必需的生命元素，开发富硒农产品是提升人体硒摄入的安全有效途径，富硒土地资源是开发富硒农产品的基础。然而，近年来全国开展的多目标地球化学调查发现，富硒土壤中重金属元素镉通常较高，不利于富硒土地开发利用，因此，研究富硒土壤区镉的地球化学特征和生态风险状况对于富硒土地开发具有重要的指导意义。文章对承德市富硒土壤区表层土壤中主要的重金属元素镉的地球化学特征及生态风险进行评价，旨在为承德市富硒土地开发利用提供科学依据。采用“七步提取法”研究了表层土壤镉的形态特征。同时，配套分析了苹果、玉米样品中的重金属元素镉的含量，以了解其生物有效性。结果显示:承德市富硒土壤区表层土壤镉在全区均较富集，在新积土和中性粗骨土、水田中显著富集。研究区圈定了4处镉轻度污染土壤，均在表层土壤镉的高值区。表层土壤镉形态平均含量大小顺序为:水溶态 < 离子交换态 < 强有机结合态 < 腐殖酸结合态 < 铁锰氧化物结合态 < 碳酸盐结合态 < 残渣态，生态风险相对较低。表层土壤镉未对苹果和玉米样品产生影响，苹果和玉米中镉均不超标。承德市富硒土壤区表层土壤镉的生态风险较低，暂不影响承德市富硒土地开发利用。 相似文献
15.
YUAN Xuyin DENG Xu SHEN Zhiyong GAO Yun 《中国地球化学学报》2007,26(4):384-393
The species of Cu, Pb, Zn, Cd and Cr in sediments of the Taihu Lake, China, have been analyzed using the sequential chemical extraction method. Variations in the chemical fractions of these metals and their geographic distributions have also been studied. For all five metals, the residual fraction is highest but the exchangeable fraction is lowest among all the fractions. Compared to other metals, Cd has the highest percentage in the exchangeable fraction, and Cr is associated mainly with the residual fraction. Cu in the organic fraction and Pb in the Fe-Mn fraction are the important species, whereas the lowest percentages are found for Cd in the organic fraction, Cu in the Fe-Mn oxide fraction and Pb in the carbonate fraction. With respect to spatial differences, the total contents in the non-residual fractions of the metals in bay sediments are found to be higher than those in other sediments. The fractions of Cd, Cu and Cr showed significant variations in different regions. The fractions of Pb and Zn, however, did not show significant variations in spatial distribution, suggesting different amounts and different paths of anthropogenic input for the metals. Comparisons of the metal speciation indicated that Cd might be the most bioavailable metal, followed by Pb. 相似文献
16.
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
17.
煤及其转化产物中重金属形态分布研究 总被引：1，自引：1，他引：1
参考Tessier形态分析程序，对煤及其转化产物中的Mn、Mo和Pb的存在形态进行了实验研究，为原煤使用形态转化中的环境效应评价提供参考。结果表明，Mn、Mo和Pb在原煤、煤焦、气化灰、燃煤灰中的形态变化依次为：可交换态、碳酸盐结合态比例下降，铁锰水合氧化物结合态比例上升；各元素的可交换态和碳酸盐结合态含量之和在原煤、气化灰、燃煤灰中依次减少；对原煤和煤焦中的有机态重金属的重复及高提取剂浓度提取是有效的。 相似文献
18.
Samir M. Nasr Mohamed A. Okbah Wafaa I. El-Anany Naglaa F. Soliman 《Geochemistry International》2018,56(2):182-188
A five step sequential extraction technique, following Tessier’s protocol has been applied to determine the chemical association of aluminium with major sedimentary phases (exchangeable, carbonate, manganese and iron oxides, organic and residual fraction) in four short sediment cores collected from El-Burullus lagoon of the Nile delta, Egypt. This study is a first approach of chemical fractionation of aluminium in one of the protective areas of the Mediterranean Sea of Egypt. The total metal content was also determined. The results of the fractionation study indicated that aluminium was mainly associated with the residual fraction (>95%). The organic and Fe–Mn oxide fractions were the next important phases. The exchangeable and carbonate fractions were less than 1%, limiting its potential toxicity as a pollutant. The geochemical analysis of aluminium forms reflected the lithogenic origin of this metal in the study area. 相似文献
19.
A comparison between heavy metals released from soil and its efficient speciation extracted by sequential extraction procedure 总被引：2，自引：0，他引：2
ZHANG Hui 《中国地球化学学报》2008,27(1):36-40
A simulating experiment was carried out on the interaction between natural precipitation and soil. The results demonstrated that the contents of heavy metals （V, Co, Cr, and Ni） released from soil into the solution under Earth＇s surface conditions are higher than the contents of those metals bonded to exchangeable species, which were extracted by sequential extraction procedure recommended by Tessier and others in 1979. It is demonstrated that the metals bonded to other 3 species （carbonate, Fe-Mn oxide, and organic matter） except those bonded to the exchangeable species in efficient speciation can be released under the Earth＇s surface conditions, when pH=4 in the reaction system, and the higher correlation coefficient indicated that the concentrations of heavy metals released from soil into the solution vary approximately with reaction time in terms of index regulations. 相似文献