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1.
Mine tailing soils created from the copper extraction in Touro Mine (Northwest Spain) are very degraded both physically and chemically. Three plots in this mine tailing were amended with Technosols in different proportions in each one to know if this mixture improved the physico-chemical characteristics of the mine soil and contaminated it with heavy metals. The Technosols were made of organic wastes, including mussel residues, wood fragments, sewage sludges and paper mill ashes. An unamended area was used as a control soil. Pseudototal and diethylenetriaminepentaacetic acid (DTPA)-extractable contents of Al, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in soil samples. The untreated soil had significant limitations for vegetation growth. All the Technosols improved the properties of the mine soil by increasing organic carbon and pH value, but they added Ni, Pb or Zn to the soil. It is advisable to check whether the heavy metal concentrations of the wastes are hazardous or not before adding to soils. It is also necessary to study the effect of these wastes over time and in more areas to conclude if they are actually favourable to restore degraded mine soils.  相似文献   

2.
Metal availability in soils is strongly related with sorption processes and the possible association of the metal ions with a particular particle-size fraction. Therefore, studies of metal retention by a soil will be aided if retention by different size fractions is also studied. Sorption of copper on a calcareous soil and its textural fractions was studied in batch assays. The soil was amended over 3 years with two agroindustrial residues, a composted olive mill sludge and vinasse. Sorption of Cu on the calcareous soil was very large (110 mmol kg−1) and was enhanced by both amendments. Metal retention by the clay fraction of the unamended soil was less than that of the whole soil, but increased dramatically after amendment with olive mill sludge. This was caused by the larger calcite content in this fraction as well as the increase in organic matter content. The amount of Cu sorbed was very large in the silt fraction, again because of the carbonate content of this fraction (300–460 g kg−1). Copper sorption decreased dramatically after removal of carbonate. Copper retention tended to be enhanced by organic amendments. This was particularly evident in the silt fraction, as a consequence of the organic matter accumulation in this fraction.
Copper sorption on the calcareous soil and its silt fractions (unamended and amended) was irreversible. By contrast, desorption was measurable from all the carbonate-free samples (both whole soil and textural fractions), although in all cases a large hysteresis was observed. We conclude that carbonate was the main component responsible for the lack of reversibility.  相似文献   

3.
The wastes used to amend soils sometimes have high concentrations of metals such as nickel (Ni), lead (Pb) and zinc (Zn). To determine the capacity of soils to retain these metals, the sorption capacities of different mine soils with and without reclamation treatments (tree vegetation and waste amendment) for Ni, Pb and Zn in individual and competitive situations were evaluated using the batch sorption technique. The untreated settling pond soil had low capacity for Ni, Pb and Zn retention. The site amended with wastes (sewage sludges and paper mill residues) increased the sorption capacity most, probably because of the higher concentrations of soil components with high retention capacity such as carbon and clay fraction. No significant competition was observed between metals in the competitive sorption experiment, indicating that the maximum of sorption was not achieved by adding 0.5 mmol L-1 of metal. We can conclude that, despite the possible additions of Ni, Pb and Zn from wastes to degraded soils, sewage sludges and paper mill residues have a high sorption capacity that would prevent the metals from being in a mobile form.  相似文献   

4.
M. J. KHAN  D. L. JONES 《土壤圈》2009,19(5):631-641
Soil samples from a historic copper mine tailing site at the Parys Mountain,North Wales (UK) were amended with green waste compost (GC),GC+30% sewage sludge (GCS),lime and diammonium phosphate (DAP),to determine the effect of amendments on DTPA-and Ca (NO3) 2-extractable metals in the mine tailing and on the phytoavailability of heavy metals by a lettuce (Lactuca sativa L.).Both compost were added at the rate of 10% by weight,lime was added as calcium carbonate equivalent (pH = 7) and DAP at a 2300 mg kg-1 soil level.The experiment was arranged in randomised complete design with three replicates in pots under control environment.Addition of lime resulted in the largest reduction in metal extractability with DTPA and Ca (NO3) 2 and phytoavailability of Cu,Fe and Zn while DAP was effective in lowering Pb extractability and phytoavailability.With exception of Zn,all other metals extracted decreased with time after amendment applications.The distribution of heavy metals between and within the four procedures of potentially bioavailable sequential extraction (PBASE) varied significantly (P < 0.001).Stronger relationships were noted between the metals extracted with PBASE SE1 and Cu,Pb (P < 0.01) and Fe (P < 0.001) in the lettuce.These results indicate that addition of lime is sufficient to restore the vegetative cover to a high metal mine waste while DAP is good for stabilizing Pb,but its detrimental role on plant growth and the risk associated with presence of N in DAP (through N leaching) may restrict its chances for remediation of contaminated sites.  相似文献   

5.
黑龙江省海伦市农田土壤重金属分布特征及污染评价   总被引：12，自引：4，他引：8  
陈玉东  王火焰  周健民  赵永存 《土壤》2012,44(4):613-620
海伦市是以农业为主导产业的黑龙江省县级市,为了解该市土壤重金属时空分布特征及其污染现状,对农田耕层及亚耕层土壤中Cd、Cr、Cu、Ni、Pb、Zn、Hg和As等重金属全量进行了分析,并采用单因子污染指数法和Nemerow综合污染指数法分别对土壤的重金属污染状况进行了评价。结果表明,该地区土壤重金属含量较低,总体表现为西南和西北含量较高、西部含量高于东部的空间分布特征。以松嫩平原土壤元素背景值为标准进行评价,已出现一定程度的污染。以GB15618-1995土壤环境质量标准二级标准进行评价,综合污染指数为0.504,所有样点土壤重金属均未达到污染水平。与耕层土壤相比,亚耕层土壤Hg和Cd含量显著下降,其他元素含量及分布特征则与耕层相似。从1980年到2008年,随着时间的变化,该区域土壤重金属含量增加趋势不明显,近期土壤出现重金属污染风险较小。  相似文献   

6.
陈国栋 《土壤通报》2013,(1):222-226
选取凤县典型铅锌矿区银洞梁8个监测点的土壤样品,在实验室应用空气-乙炔火焰原子吸收分光光度法进行Cu、Zn、Pb、Cd、Cr五种重金属全量测定。应用密切值法对8个监测点的土壤重金属污染程度进行综合评价,结果表明该矿区土壤已受不同程度重金属污染,其中两个监测点达到了严重污染程度。考察了密切值法的综合评价与单因子污染指数法评价两结果之间的关系,结果表明具有较强迁移能力的矿区主要污染物Zn能够较好的表征矿区土壤重金属的综合污染状况。  相似文献   

7.
An experiment was conducted to examine the accumulation and mobility of heavy metals (Zn and Cu) at different depths in three types of arable soils (Brown Lowland soil, Andosol, and Brown Forest soil) amended with cattle and pig farmyard manures for 5 years. Nitric-perchloric acid digestion was performed for the determination of the total amounts of heavy metals, and 0.1 M hydrochloric acid extraction was performed for the determination of the amounts of soluble heavy metals. Results of the soil analysis indicated that pig farmyard manure application resulted in serious contamination of arable soils with Zn and potentially Cu. Especially, the Brown Forest soil displayed a high ability to accumulate heavy metals on the soil surface. Total-Zn concentration in surface soils was considerably affected by the holding capacity of soluble-Zn traction. Although the Andosol amended with pig farmyard manure showed higher concentrations of heavy metals related to the higher ability of retention on a weight basis, the soil did not contribute to high heavy metal accumulation because of its low bulk density. Heavy metals were easily leached in sandy soils such as Brown Lowland soil, and Cu was potentially stable compared with Zn. We suggest that long-term pig farmyard manure application to the Brown Lowland soil and Andosol with a light soil texture is associated with a higher risk of groundwater pollution than the application to the Brown Forest soil.  相似文献   

8.
The present study was conducted to assess the suitability of sewage sludge amendment in soil for Beta vulgaris var. saccharifera (sugar beet) and Triticum aestivum (wheat) by evaluating the arsenic and selenium accumulation and physiological responses of plants grown at 10%, 25%, and 50% sewage sludge amendment rate. Sewage sludge amendment was modified by the physicochemical properties of soil, thus increasing the availability of heavy metals in the soil and consequently with higher accumulation in plant parts. The chlorophyll contents increased after the sewage sludge treatments except for 50%. The sewage sludge amendment led to a significant increase in arsenic and selenium concentrations of the soil. The heavy metal accumulation in the soil after the treatments did not exceed the limits for the land application of sewage sludge recommended by the US Environmental Protection Agency. The increased concentration of heavy metals in the soil due to the sewage sludge amendment led to increases in heavy metal uptake in the leaves and root concentrations of arsenic and selenium in plants as compared to those grown on unamended soil. Accumulation was more in roots than shoots and leaves for most of the heavy metals. Concentrations of arsenic and selenium were more than the permissible limits of national standards in the edible portion of sugar beet and wheat grown on different sewage sludge amendments ratios. The study concludes that the sewage sludge amendment in the soil for growing sugar beet and wheat may not be a good option due to risk of contamination of arsenic and selenium.  相似文献   

9.
土壤微生物对土壤重金属污染反应敏感,是探讨矿区土壤重金属污染生态效应的有效指标之一。通过野外调查与采样和室内分析,研究了藏中矿区重金属污染对土壤蔗糖酶、脲酶、脱氢酶和酸性磷酸酶活性、微生物生物量C（MBC）、N（MBN）和P（MBP）、土壤基础呼吸、代谢商（qCO2）及可矿化N的影响。研究表明,矿区土壤重金属Cu、Zn、Pb、Cd全量和有效含量均高于对照土壤;随着矿区土壤重金属含量增加,土壤酶活性、微生物量C、N和P、可矿化N均逐渐降低,土壤基础呼吸和qCO2则逐渐升高;土壤重金属与土壤蔗糖酶活性、脲酶活性、脱氢酶活性、酸性磷酸酶活性、MBC、MBN、土壤基础呼吸、qCO2及可矿化N具有显著的线性相关;脱氢酶活性对土壤重金属污染最为敏感,表明脱氢酶活性可作为藏中矿区土壤环境质量变化的有效指标。  相似文献   

10.
金属矿山在开采过程中对矿区及周围的生态环境造成了较为严重的重金属污染.因此,在金属矿区开展重金属污染治理对于减轻重金属危害、确保农作物安全生产、保障人民健康,具有长远而重大的意义.笔者就植物措施在金属矿山水土流失防治中的特殊作用作一简要概括,对金属矿山植物措施防治水土流失的现状、植物修复技术的特点、超富集植物的筛选方法及筛选成果、影响植物措施在金属矿山水土流失防治中发挥特殊作用的因素等作了介绍,以期能为金属矿山的生态环境治理提供参考.  相似文献   

11.
Traditionally, the Guadiamar River (Seville, Southwest Spain) has received pollution from two different sources, in its upper section, from a pyrite exploitation (Los Frailes mine) and, in its lower section, from untreated urban and industrial wastes and from intensive agricultural activities. In 1998, the accidental spillage of about 6 million m3 of acid water and sludge from mine tailings to Guadiamar River worsened the pollution of an already contaminated area. The main polluting agents of the spillage were heavy metals. The total concentration of a metal provides scarce information about the effects on environmental processes or about the toxicity of the sediment samples. A more sophisticated fractionation of the sediment samples based on a species distribution can help to understand the behaviour and fate of the metals. This article describes a distribution study of the metals Al, Cd, Cu, Fe, Mn, Pb and Zn by fractionation analysis of sediments from eleven sample sites alongside the Guadiamar Riverbed. The samples were collected in summer 2002, four years after the spillage and after the area had been cleaned. Sequential extraction analysis resulted in the definition of four fraction categories: exchangeable metal (the most available fraction), reducible metal (bound to hydrous oxides of Fe and Mn), oxidizable metal (bound to organic matter and sulphides) and a residual fraction (bound to minerals). Significant increases in the available fraction of several potentially toxic metal ions like Cd, Mn and Zn were found. The distribution pattern was variable along the River. At the site closest to the mineworks, the soluble forms of Cd, Mn and Zn were significantly more abundant that those downstream. Cu and Pb were present in the reducible fraction while Fe was present associated in the residual fraction.  相似文献   

12.
Large quantities of mussel shells(66 000-94 000 t year 1),an alkaline material that can be used as a soil amendment,are generated as waste in Galicia,NW Spain.A field trial was carried out by planting different pasture species in a Haplic Umbrisol using a randomized block design with four blocks and six treatments(not amended control or soil amended with lime,finely ground shell,coarsely ground shell,finely ground calcined shell or coarsely ground calcined shell) to compare the effects of lime and mussel shells additions on a soil with a low cation exchange capacity and high Al saturation.The trial was established in March 2007,and samples of plants and soil were collected when plots were harvested in summer 2008(separating the bulk and rhizosphere soil).The soils were analyzed for pH,total C,total N,available P,exchangeable cations,effective cation exchange capacity and available micronutrients.Dry matter yield was measured in all plots and plants were analyzed for nutrients.Application of mussel shells and the commercial lime resulted in an increase in pH and exchangeable Ca and a decrease in exchangeable Al and Al saturation.The stability of pH over time was high.These effects were most noticeable in the rhizosphere.The amendment also had a positive effect on dry matter yield and concentration of Ca in the plant.  相似文献   

13.
When acid soil has been contaminated by metals as a result of industrial discharges, accidental spills, or acid mine drainage it may be desirable to retain the metals in the soil rather than allow them to leach away. We have investigated the potential of phosphogypsum (PG), sugar foam (SF), and phosphoric rock (PR) to regulate the availability and mobility of Pb, Cd and Cu. We have also identified changes in attenuation during incubation for 1 year and the effect of aging on metal speciation in amended soils. We studied miscible displacement in columns of undisturbed soil previously treated with solutions of the amendments and soluble metals and, subsequently, single and sequential chemical metal extractions. All amendments increased the soil's metal retention capacity. This, in turn, increased the amount of metal extractable by diethylenetriaminepentaacetic acid (DTPA). However, over time the amounts of DTPA‐extractable metal decreased, particularly for Cu and Pb. Both Cu and Cd were held preferentially within the acetic acid‐extractable fraction (operationally defined exchangeable fraction – EX fraction), whereas Pb was associated mainly with the hydroxylammonium‐extractable fraction (operationally defined bound to Fe and Al hydroxides – OX fraction). Both Pb and Cu in the oxide and organic fractions increased in the PG‐ and SF‐treated soils. In general, the distribution of metal did not change in the PR‐treated columns after the incubation. Finally, scanning electron microscopy in back‐scattered electron mode (SEM–BSE) showed the formation of Al‐hydroxy polymers which provides the soils with additional cation sorption capacity. In the PG‐ and PR‐treated columns, P and S were associated with these formations. The three metals were associated with the Al polymers, probably through direct coordination or the formation of ternary complexes with the inorganic ligands phosphate and sulphate.  相似文献   

14.
M. Jalali  Z.V. Khanlari 《Geoderma》2008,143(1-2):26-40
This study was conducted to investigate the effect of time on lead (Pb), zinc (Zn), cadmium (Cd) and copper (Cu) availability in some calcareous soils of Iran. Heavy metals were added to soils at the rate of 500 mg kg? 1 of Pb, Zn, and Cu and 8 mg kg? 1 of Cd as chloride. The samples were incubated for 3 h, 1, 3, 7, 14, 21, and 28 days at 25 °C and constant moisture. After incubation, metals in amended and control soils were fractionated by the sequential extraction procedure. There were changes in the proportional distribution of heavy metals in all five studied soils during 28 days of incubation with spiked heavy metals. In general the proportions of heavy metals associated with the most weakly bound fraction (EXCH) tended to decrease, with corresponding increases in the other five more strongly binding fractions during the incubation. The distribution of added heavy metals into different solid phase fractions appears to be consisted of two phases involving the initial rapid retention followed by a slow continuous retention. Three kinetic equations were used to fit the experimental data. The parabolic equation fits well the data used in this work. The transformation rate of EXCH fraction for soils was estimated by parabolic equation for above incubation periods. There were differences in the rates at which redistribution took place between soils and heavy metals. The constant b in parabolic equation was defined as the transformation rate, which were in the order Cu > Zn ≥ Pb ? Cd. The higher proportions of EXCH fraction of spiked Cd in these calcareous soils indicates its higher potential of downward leaching and runoff transport especially at the early stage of pollution.  相似文献   

15.
研究了杭州市50个代表性居民小区土壤重金属(Cd、Cr、Cu、Ni、Pb和Zn)的含量,按照国家《土壤环境质量标准》对该市居民区土壤重金属污染状况做出了评价,并在GIS技术支持下,研究了土壤重金属污染的空间变异性。结果表明,杭州市居民区土壤均受到了不同程度的污染。其中4%的土壤轻度污染,54%的土壤中度污染,42%的土壤严重污染。土壤重金属污染具有显著的空间分异特征,严重污染区域大致呈西北-东南走向,包括了城北的大部分地区、市中心和城东南一些地区。工业生产和居民区形成时间对居民区土壤重金属积累有较大的影响。  相似文献   

16.
污泥与施污土壤重金属生物活性及生态风险评价   总被引：3，自引：0，他引：3  
将城市污泥以不同质量比施于土壤中构成污泥混合土壤,研究各污泥配比土壤中重金属的生物活性,并采用三种重金属评价方法(地累积指数法、潜在生态风险指数法、综合毒性指数模型)和黑麦草对重金属的吸收富集效果来对施污土壤中重金属具有的生态风险性进行评价。结果表明:污泥的添加使土壤中生物活性态Cd、Cu和Zn含量显著增加,对三种重金属具有活化作用,但对Pb却起到钝化作用。生态风险评价结果表明:污泥的添加使土壤中Pb呈现无污染和低生态风险;Cu和Zn呈现中度污染和低生态风险;Cd达到强度污染和重度生态风险,重金属潜在生态风险(RI)总体处于强度生态风险水平。当污泥添加比例大于6:10(污泥S3处理)时,施污土壤中重金属的综合毒性指数高于土壤对照。黑麦草对Cd、Pb、Cu和Zn的富集浓度与施污土壤中对应重金属的生物活性态含量存在显著正幂指数关系,同时黑麦草对施污土壤中Cd、Cu和Pb的富集能力大小与地累积指数法和潜在生态风险指数法对三种重金属具有的生态风险性的评价结果具有一致性。  相似文献   

17.
重金属对典型富铁土吸持磷的影响的动力学研究   总被引：1，自引：0，他引：1  
  相似文献   

18.
云南省个旧锡矿区重金属污染评价及植被恢复初探   总被引：4，自引：0，他引：4  
通过对云南个旧锡矿区废弃地重金属的野外调查和室内测定,运用地质累积指数对重金属污染进行了评价.结果表明,研究区废弃地重金属含量从高到低依次为Cd>Mn>Pb>As>Zn>Cu=Fe,其中Cd和Mn的地质累积指数最高,平均达到了4.55以上,污染等级达到5级,属于强度污染到极强度污染;Pb的地质累积指数平均达到了3.08以上,污染等级为4级,属于强度污染;As和Zn的平均地质累积指数分别为2.37和1.97,污染等级分别为3级和2级,达到了中度污染以上;Cu和Fe的平均地质累积指数均小于0,没有产生污染;采用造林措施对矿区废弃地进行复垦较采用农业措施对于治理矿区重金属污染具有更好的效果,因此可以采用覆土造林方式作为矿区废弃地复垦的主要方式.最后,结合不同地块重金属污染状况评价结果,提出了针对废弃地进行植被恢复的主要植物种.  相似文献   

19.
南通市城市边缘带土壤重金属污染现状及评价   总被引：8，自引：0，他引：8  
黄辉  檀满枝  周峰  陈杰  潘根兴 《土壤》2007,39(2):286-290
通过对不同土地利用方式下的7个样区进行系统的采样测定,对南通城市边缘带土壤重金属富集与污染状况进行了分析与评价。结果显示,研究区土壤未发生明显的重金属污染。但3个样区的土壤有轻度的重金属污染现象,Zn是发生富集最普遍的元素,约76%的样点土壤Zn富集指数>1,18%的样点土壤出现Zn的轻度污染。Cu、Pb等重金属元素导致的污染也在零星样点被发现。方差分析表明,土地利用方式不是导致研究区土壤重金属含量空间差异的主要因素,而土壤类型、样区空间环境与土壤重金属含量及富集、污染有相对密切的关系。  相似文献   

20.
Abstract

The role of intrinsic soil properties and management induced changes in bulk density on legume shoot biomass‐nitrogen (N) turnover to soil mineral N [nitrate (NO3) plus ammonium (NH4)], SMN, through soil microorganisms is poorly understood. In this study, the influence of intrinsic soil properties and changes in bulk density in soils amended with red clover (Trifolium pratense L.) on N immobilization/remineralization was investigated. Time in incubation, soil type, bulk density, and legume amendment had significant influence on the amounts of microbial biomass carbon (C) (MBC), N (MBN), and the SMN measured during incubation. During the first 32 days in incubation, MBC and MBN in the legume‐amended soils were higher than the control whereas an opposite trend existed for SMN. The SMN measured at the end of incubation, i.e., 70 days after incubation, was significantly higher than the unamended control. The ratio of SMN to MBN (SMN:MBN) was < 1.0, in general, during the first 32 days in incubation in legume amended soils, indicating N immobilization in microbial biomass during this period. Forty‐two days after incubation, the SMN:MBN ratios in the legume amended soils were >1.0, indicating remineralization of the immobilized N, derived, at least partially, from the legume. In the unamended control, these ratios were > 1.0 throughout the incubation. Over time, 63% to 76% of the variability in N‐immobilization/remineralization (SMN:MBN) was accounted for clay content, water (WFP) and air (AFP) filled porosities, volume fraction of pores (VFP) <1.5 μm, total N, C to N ratios in soils, bulk density, and legume amendment. The results indicate the influence of intrinsic soil properties and bulk density on microbially mediated legume N turnover to SMN changed over time.  相似文献   

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