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1.
Gupta AK  Sinha S 《Chemosphere》2006,64(1):161-173
A pot experiment was carried out to study the single and sequential extractions of metals in different tannery sludge amendment and the potential of the plant of Sesamum indicum L. var. T55 (sesame) for the removal of metals from tannery waste contaminated site. The metal extraction efficiency obtained with each extractants was slightly different and follow the order; EDTA>DTPA>NH(4)NO(3)>NaNO(3)>CaCl(2). The correlation analysis between extractable metals in the different amendments of sludge and metal accumulation in the plant (lower and upper parts) showed better correlation for most of the tested metals with EDTA extraction. In this study, a sequential extraction technique was applied on different amendments of tannery sludge. The results showed that Mn, Zn, Cr and Cd were mostly associated with Fe-Mn oxide fraction in most of the amendments, K and Ni was found in residual (RES) fraction, Fe and Cu was bound with organic matter (OM) and RES fractions and Na was associated with carbonate (CAR) fraction. The metal accumulation after 60 d of growth of the plant was found in the order of K>Na>Fe>Zn>Cr>Mn>Cu>Pb>Ni>Cd and its translocation was found less in upper part. The accumulation of toxic metals (Cr, Ni and Cd) in the plants was found to increase with increase in sludge ratio, in contrast, the accumulation of Pb decreased. In view of growth parameters and metal accumulation in the plant, it was observed that lower amendments (25%) of tannery sludge were found suitable for the phytoremediation of most of the studied metals.  相似文献   

2.
Surface soil samples were collected from 52 sites around Guanting Reservoir in Beijing, China, and contents of 'total' metals (Cu, Zn, Pb, Cd, As, Ni and Cr) were determined. The results indicate that the degree of heavy metal pollution in the soils declines in the order of Cd>Cr>Zn>As>Cu>Ni>Pb. Based on the results of a combination of multivariate statistics and geostatiscal analyses, it was concluded that land application of phosphate fertilizer, wastewater and sludge were the primary sources of Cd and Zn in soils. Whereas As, Cu, Cr and Ni in some soils were due to natural rock weathering. The sources of Pb in soils only partially originated from land application of phosphate fertilizer, but mainly from vehicle exhaust. The greatest concentrations of all metals, except for Pb, were found in Huailai County and the towns of Yanghedaqiao and Guanting.  相似文献   

3.
Leaching of metals from sewage sludge can lead to their accumulation in topsoil and can also contaminate groundwater. Our objectives were to document the metal leachates and the size distribution of leached particles from sewage sludge and to identify possible correlations with physical factors. Results from monthly lysimeter sampling showed an initial release followed by decline for most metals. Cadmium, Ca, Sr, Li, Mn, Ni and Zn showed a "cyclic" behaviour. Filtration revealed that this "cyclicity" had no correlation to the size of released particles, but Al, Cr, Fe, Cu, Ag and Pb were clearly related to release of coarser particles most of the year. Total metal amounts leached during one year, relative to original sludge content, had the order Na>Ca=Mg>Mn>Sr>Zn>K>Li=Ni>Cd>Co>Rb>Ag>Cr>Ba=Cu>Ga>Al=Pb=Fe. There were no simple correlations between monthly measured leachate concentrations and precipitation, temperature or pH of precipitation. Occasional leachate sampling might give misleading values for metals with "cyclic" behaviour.  相似文献   

4.
巢湖表层沉积物中重金属的分布特征及其污染评价   总被引:14,自引:1,他引:13  
以巢湖表层沉积物为研究对象,利用BCR连续提取法研究了沉积物中Cr、Co、Ni、Cu、Cd、Zn、V和Pb等8种重金属元素的分布特征,同时运用潜在风险指数法和地累积指数法综合评价了巢湖沉积物中重金属的生态风险。结果表明,巢湖沉积物中的重金属含量在空间上表现出东西高、中间低的分布特征。巢湖表层沉积物中Cr、Co、Ni、V和Cu 5种重金属都主要以残渣态为主,Zn和Cd主要以弱酸提取态为主,Pb以可还原态为主,同时,Co和Cu 2种元素的可交换态及可还原态含量占有较高比例,具有潜在危害性。相关性分析显示,Cr、Cu、Pb、Ni、Zn和Cd 6种重金属元素的来源和分布可能具有相似性,Co和V 2种重金属元素具有相似的地球化学行为且其主要来源可能与其他几种重金属不同。潜在生态风险指数评价结果表明,巢湖表层沉积物中8种重金属元素构成的生态危害顺序为:Cd>Pb>Co>Cu>Ni>Zn>V>Cr,Cd具有高的生态危害等级,其他7种重金属元素均为低生态危害等级。地累积指数法评价结果表明:巢湖沉积物重金属元素的富集程度为Cd>Zn>Pb>Co>Cu>V>Ni>Cr,Cr属于清洁级别,Co、Cu、V和Ni处于轻度污染水平,Zn和Pb处于偏中度污染,Cd达到了重污染水平。  相似文献   

5.
Ambient suspended particulate concentrations were measured at Tzu Yun Yen temple (120 degrees, 34('), 10(") E; 24 degrees, 16('), 12(") N) in this study. This is representative of incense burning and semi-open sampling sites. The Universal-sampler collected fine and coarse particle material was used to measure suspended particulate concentrations, and sampling periods were from 16/08/2001 to 2/1/2002 at Tzu Yun Yen temple. In addition, metallic element concentrations, compositions of PM(2.5) and PM(2.5-10) for incense burning at Tzu Yun Yen temple were also analyzed in this study. The PM(2.5)/PM(10) ratios ranged between 31% and 87% and averaged 70+/-11% during incense the burning period, respectively. The median metallic element concentration order for these elements is Fe>Zn>Cr>Cd>Pb>Mn>Ni>Cu in fine particles (PM(2.5)) at the Tzu Yun Yen temple sampling site. The median metallic element concentration order for these elements is Fe>Zn>Cr>Pb>Cd>Ni>Mn>Cu in coarse particle (PM(2.5-10)) at the Tzu Yun Yen temple sampling site. Fine particulates (PM(2.5)) are the main portion of PM(10) at Tzu Yun Yen temple in this study. From the point of view of PM(10), these data reflect that the elements Fe, Zn, and Cr were the major elements distributed at Tzu Yun Yen temple in this study.  相似文献   

6.
煤矿复垦区土壤重金属分布特征与质量评价   总被引:2,自引:0,他引:2  
为保证煤矿复垦区种植农作物的充填复垦土壤的生态安全,以淮南矿区煤矸石充填复垦地为研究对象,通过对研究区内Cd、Cr、Ni、Pb、Cu、Zn和Hg 7种重金属不同深度含量分析,总结其纵向分布特征,并将研究区土壤重金属含量与淮南市土壤背景值、《土壤环境质量标准》(GB 15618-1995)作比较,分析这7种重金属的污染程度.结果表明,这7种重金属都有不同程度的污染,其中土壤受Cd污染最严重,土壤中重金属垂直方向上无确定分布规律.总体而言,土壤重金属潜在生态风险属于强生态危害.从垂直方向来看,重金属潜在生态风险指数(RD随着深度的增加出现先下降后升高的趋势,其中40~60 cm深度的RI最大.重金属生态危害程度依次为Cd> Hg> Ni> Cu> Cr> Pb> Zn,其中Cd为矿区土壤中最主要的重金属污染生态风险因子.  相似文献   

7.
Sewage sludge-amended soils may alter their ability to adsorb heavy metals over time, due to the decomposition of sludge-borne organic matter. Thus, we studied Cd, Ni, and Zn adsorption by a sewage sludge-amended soil (Typic Xerofluvent) before and after one-year incubation in both monometal and competitive systems. In the monometal system, the order of decreasing sorption was Zn>Cd>Ni. Competition significantly reduced metal K(d), especially that of Cd which decreased by nearly 50%. Over the course of the incubation there was a 31% reduction of soil organic matter content. At the same time, in competitive systems Cd K(d) significantly decreased, while Zn K(d) significantly increased, and Ni K(d) remained unaffected. This study shows that sewage sludge-amended soils may change in their ability to sorb heavy metals over time at high metal concentrations. The data suggest that Cd is likely to be of most environmental significance in such soils, since it exhibited decreased sorption under competitive conditions and as the organic matter content of the soil was reduced. The potential for long-term release of metals should be considered in the risk assessment associated with sewage sludge addition to soils, particularly in climates where degradation of organic matter is likely to be enhanced.  相似文献   

8.
基于主成分分析法的辽河水体中溶解性金属来源分析   总被引:1,自引:0,他引:1  
在测定辽河水体中几种主要的溶解性金属(包括7种重金属)的含量和分析其空间分布特征的基础上,运用主成分分析(PCA)法分析了金属的可能来源。结果表明,辽河水体中溶解性金属的平均浓度为Al>Cu>Zn>Cr>Hg>As>Pb>Cd,与欧美发达国家的主要水体相比,辽河水体的金属污染状况总体较重;辽河水体中溶解性金属的污染来源主要分两类:农业面源和工业废水污染源,工业综合污染源;根据主成分得分系数可知,采样点2(通江口)、3(三合屯)、7(朱尔山)的金属污染主要来源于农业面源和工业废水污染源;采样点6(药王庙)的金属污染主要来源于工业综合污染源;基于PCA法的金属来源分析对辽河流域水体金属污染治理对策的制定有着重要的指导意义。  相似文献   

9.
The study area (Szklary Massif, SW Poland) comprises three sites of different soil provenance: (1) natural serpentine Cambisol, (2) anthroposol situated on waste dump and (3) cultivated Inceptisol developed on glacial tills next to the dump. Potentially toxic elements (PTE) have either lithogenic or anthropogenic origins in these sites. The chemical partitioning of Co, Cr, Cu, Ni, Pb and Zn among solid forms was determined by sequential extractions coupled with direct mineral identifications (SEM, electron microprobe analysis - EMPA, and XRD). Examination of solid residues after several extraction steps was conducted in order to discuss the indirect speciation obtained by the extraction method. Total concentrations of PTE having anthropogenic origin greatly exceed those of lithogenic origin. Mobility of studied PTE is variable in the different environments except for Cr which is always mostly found in residual fractions of extractions. Cu and Pb are more mobile than Cr and Co in all soils. Zn is more stable (Cu>Pb>Ni>Co>Zn>Cr) in the serpentine soil and cultivated epipedon (Pb>Cu>Zn>Ni>Co>Cr) than in the anthroposol (Zn>CuPb>Ni>Co>Cr). PTE of lithogenic origin are generally less mobile than those from anthropogenic origin except Ni which is more mobile in the serpentine soil. Nonetheless, mineral forms of metals better determine their mobility than metal origin. Identification by direct methods of the PTE mineral form was not possible for metals present at low concentrations (Cu, Pb). However, direct mineralogical examinations of the solid residues of several extractions steps improved the assessment of the PTE solid speciation and mobility, particularly for Cr, Ni and Zn.  相似文献   

10.
Concentration of heavy metals and natural gross radioactivity were measured in the surface water and sediment of Hazar Lake (Elazi?, Turkey). Eight sampling sites were pre-defined in different locations of the lake. A preliminary study on heavy metals (Zn, Fe, Mn, Ni, Cu, Cr, Co and Pb), major elements (Na, K, Ca, Mg) concentrations and natural radioactivity related to 226Ra, gross-alpha and gross-beta radiations in the surface water and deep sediments were determined. The obtained results showed that, in general, the heavy metals (Zn, Fe, Mn, Ni, Cu and Pb) and major elements (Na, K, Ca, Mg) concentrations in water did not exceed WHO (World Health Organization, 1999), EC (Europe Community, 1998), EPA (Environment Protection Agency, 2002) and TSE-266 (Turkish Standard, 1997) guidelines. Generally, heavy metals and major elements concentration of the sediments were found decrease in sequence of Fe>Mg>Ca>Mn>Zn>Ni>Cr>Cu>Co>Pb. The results of this study indicated that a general absence of serious pollution in the Hazar Lake. The results obtained from the radioactivity determination indicate that the surface water radioactivity concentration of 226Ra, gross-alpha and gross-beta were ranging from 0.52+/-0.02 to 2.02+/-0.06 Bq/l and from 0.65+/-0.03 to 2.52+/-0.07 Bq/l and from 0.01+/-0.01 to 0.14+/-0.01 Bq/l, respectively. Deep sediment radioactivity concentrations of 226Ra is ranging from 0.07+/-0.03 to 0.32+/-0.07 Bq/g.  相似文献   

11.
Altindağ A  Yiğit S 《Chemosphere》2005,60(4):552-556
The accumulation of heavy metals (Cd, Pb, Hg and Cr) was measured by atomic absorption spectrophotometry in water, sediment, plankton and fish samples collected from Lake Bey?ehir, which is important bird nesting and visiting areas, and irrigation and drinking water sources. In Lake Bey?ehir, the accumulation orders of heavy metals were Cd>Pb>Cr>Hg in water, Pb>Cd>Cr>Hg in sediment, Pb>Cd>Cr>Hg in plankton, and Cd>Pb>Cr>Hg in the muscles and gills of chub, carp, tench, except for the muscle of pikeperch, in which it was Pb>Cd>Cr>Hg (P<0.05). In addition to this, accumulation orders of heavy metals in the food web was also found to be water>plankton>sediment>fish tissues, except for Cr. According to international criterias and Turkish regulations, heavy metal concentrations especially Cd and Pb in Lake Bey?ehir were markedly above the permissible levels for drinking water.  相似文献   

12.
Increased consciousness for safeguarding the aqueous environment has prompted a search for alternative technologies for the removal of toxic metal ions from aqueous solutions. In this regard, a wide variety of biomass is being considered as adsorbents of heavy metals for treatment of industrial and domestic wastewaters as well as natural waters, including drinking water. In the present investigation, the potential of Quercus ilex phytomass from stem, leaf and root as an adsorbent of chromium (Cr), nickel (Ni), copper (Cu), cadmium (Cd) and lead (Pb) at ambient temperature was investigated. The metal uptake capacity of the root for different metals was found to be in the order: Ni>Cd>Pb>Cu>Cr; stem Ni>Pb>Cu>Cd>Cr; and leaf Ni>Cd>Cu>Pb>Cr. The highest amount adsorbed was Ni (root>leaf>stem). Data from this laboratory demonstrated that Ni is sequestered mostly in the roots, where concentrations can be as high as 428.4 ng/g dry wt., when 1-year-old seedlings were treated with Ni (2000 mg/l) in pot culture experiments, compared to 7.63 ng/g dry wt., control (garden and greenhouse soil) topsoil where Ni was present in trace amounts. This proves that the root biomass of Q. ilex has the capacity for complexing Ni. Cr exhibited the least adsorption values for all the three types of phytomass compared to other metals. The trend of adsorption of the phytomass was similar for Ni and Cd, i.e. root>leaf>stem. Desorption with 10 mM Na(4) EDTA was effective (55-90%) and, hence, there exists the possibility of recycling the phytomass. The biosorption results of recycled phytomass suggest that the selected adsorbents are re-usable. The advantages and potential of the Q. ilex phytomass as a biofilter of toxic trace metals, the scope and need for enhancing the efficiency of the Q. ilex phytomass as an adsorbent of metals are presented.  相似文献   

13.
Sundance sunflowers were subjected to contaminated solutions containing 3, 4, or 5 heavy metals, with and without EDTA. The sunflowers exhibited a metal uptake preference of Cd=Cr>Ni, Cr>Cd>Ni>As and Fe>As>Cd>Ni>Cr without EDTA and Cr>Cd>Ni, Fe>As>Cd>Cr>Ni with EDTA. As uptake was not affected by other metals, but it decreased Cd and Ni concentration in the stems. The presence of Fe improved the translocation of the other metals regardless of whether EDTA was present. In general, EDTA served as a hindrance to metal uptake. For the experiment with all five heavy metals, EDTA decreased Cd in the roots and stems from 2.11 to 1.36 and from 2.83 to 2.3 2mg g(-1) biomass, respectively. For the same conditions, Ni in the stems decreased from 1.98 to 0.94 mg g(-1) total metal uptake decreased from 14.95 mg to 13.89 mg, and total biomass decreased from 2.38 g to 1.99 g. These results showed an overall negative effect in addition of EDTA. However it is unknown whether the negative effect was due to toxicity posed by EDTA or the breaking of phytochelatin-metal bonds. The most important finding was the ability of Sundance sunflowers to achieve hyperaccumulator status for both As and Cd under all conditions studied. Ni hyperaccumulator status was only achieved in the presence of three metals without EDTA.  相似文献   

14.
This study was designed to evaluate the impact of sewage sludge spreading on tropical soilborne heavy metal speciation. Sludgeborne heavy metal speciation was also assessed, and the potential mobility of the elements was classified as follows: Zn>Ni>Cu approximately Cr. Two sequential extraction procedures were applied to study Cr, Cu, Ni and Zn speciation in control soils and sludge-amended soils. We demonstrated that sewage sludge spreading over a 2-year period did not have an impact on soilborne heavy metal concentrations but affected speciation of the most mobile fractions of Ni and Zn. Both protocols were consistent for the organic matter fractions, with an increase in Cu, Zn and Cr concentrations in the amended soil as compared to the control soil. In addition, we highlighted that the two protocols characterized different pools of organic matter and that organic compounds remained in the solid matrix after extraction. With respect to the reducible fraction, completely opposite results were obtained with the two protocols and the solid residue study revealed that the two schemes were ineffective in characterizing iron and manganese fractions.  相似文献   

15.
以《土壤环境质量标准》(GB 15618—1995)二级标准作为评价标准,采用以改进层次分析法确定权重的加权平均法对南京市郊典型蔬菜地的土壤重金属污染状况进行了评价。结果表明,研究区土壤中Cu、Pb、Cr的单因子污染指数平均值均小于1,含量超标率均不超过10.32%,而Cd的单因子污染指数平均值达2.15,含量超标率为84.13%,急需对该区土壤和受体做进一步的Cd污染深入调查或风险评估;研究区土壤重金属综合污染指数平均值为1.28,属玷污水平;利用ArcGIS 8.3软件进行土壤重金属污染的空间分布特征分析结果表明,研究区各元素的污染程度为Cd>Pb>Cu>Cr,各元素的污染格局较为相似,城市化活动对土壤污染贡献较大;研究区有81.16%的土壤重金属污染级别为玷污,3.78%处于本底级,15.06%处于安全级。  相似文献   

16.
Heavy metal fates in laboratory bioretention systems   总被引:5,自引:0,他引:5  
Sun X  Davis AP 《Chemosphere》2007,66(9):1601-1609
Key to managing heavy metals in bioretention is to understand their fates in bioretention facilities. In this study, pot prototypes filled with bioretention media were built to simulate the conditions of natural growth of plants. Synthetic runoff with different heavy metal loadings (copper, cadmium, lead, and zinc) was periodically applied. Metal accumulations in tissues of grasses -Panicum virgatum, Kentucky-31, and Bromus ciliatus, were investigated after 230d of growth and multiple runoff treatment events. After 183d of periodic runoff application, the concentrations of Zn, Cu, Pb and Cd with low and high loadings had the same trends in the plant tissues, Zn>Cu>Pb>Cd, following the trend of the input metal concentrations. The fates of input metals were 88-97% captured in soil media, 2.0-11.6% not captured by bioretention media, and 0.5-3.3% accumulated in plants. Compared to the metals retained by the soil, the percentages of input metals taken up by plants were relatively low due to the low plant biomass produced in this study. Greater biomass density would be required for the vegetation to have a valuable impact in prolonging the lifetime of a bioretention cell.  相似文献   

17.
Singh RP  Agrawal M 《Chemosphere》2007,67(11):2229-2240
Use of sewage sludge, a biological residue produced from sewage treatment processes in agriculture is an alternative disposal technique of waste. To study the usefulness of sewage sludge amendment for palak (Beta vulgaris var. Allgreen H-1), a leafy vegetable and consequent heavy metal contamination, a pot experiment was conducted by mixing sewage sludge at 20% and 40% (w/w) amendment ratios to the agricultural soil. Soil pH decreased whereas electrical conductance, organic carbon, total N, available P and exchangeable Na, K and Ca increased in soil amended with sewage sludge in comparison to unamended soil. Sewage sludge amendment led to significant increase in Pb, Cr, Cd, Cu, Zn and Ni concentrations of soil. Cd concentration in soil was found above the Indian permissible limit in soil at both the amendment ratios.

The increased concentration of heavy metals in soil due to sewage sludge amendment led to increases in heavy metal uptake and shoot and root concentrations of Ni, Cd, Cu, Cr, Pb and Zn in plants as compared to those grown on unamended soil. Accumulation was more in roots than shoots for most of the heavy metals. Concentrations of Cd, Ni and Zn were more than the permissible limits of Indian standard in the edible portion of palak grown on different sewage sludge amendments ratios. Sewage sludge amendment in soil decreased root length, leaf area and root biomass of palak at both the amendment ratios, whereas shoot biomass and yield decreased significantly at 40% sludge amendment. Rate of photosynthesis, stomatal conductance and chlorophyll content decreased whereas lipid peroxidation, peroxidase activity and protein and proline contents, increased in plants grown in sewage sludge-amended soil as compared to those grown in unamended soil.

The study clearly shows that increase in heavy metal concentration in foliage of plants grown in sewage sludge-amended soil caused unfavorable changes in physiological and biochemical characteristics of plants leading to reductions in morphological characteristics, biomass accumulation and yield. The study concludes that sewage sludge amendment in soil for growing palak may not be a good option due to risk of contamination of Cd, Ni and Zn and also due to lowering of yield at higher mixing ratio.  相似文献   


18.
Li C  Fang HH 《Chemosphere》2007,67(4):668-673
This study was conducted to investigate the toxicity of six electroplating metals on the H(2)-producing activity of a granular sludge sampled from an H(2)-producing upflow reactor treating sucrose-containing wastewater. The H(2) production activities of the sludge were measured in serum vials using wastewater containing not just sucrose and proper nutrient, but also individual heavy metals at concentrations ranging 0-5000 mg l(-1). The relative toxicity to H(2) production was found in the following order: Cu (most toxic)>Ni approximately Zn>Cr>Cd>Pb (least toxic). The C(I,50) values, at which the bioactivity of the sludge was reduced to 50% of the control, for individual heavy metals were Cu 30 mg l(-1), Ni and Zn 1600 mg l(-1), Cr 3000 mg l(-1), Cd 3500 mg l(-1), and Pb >5000 mg l(-1). Compared with the literature data, H(2)-producing sludge exhibited in general higher resistance to metal toxicity than methanogenic granular sludge.  相似文献   

19.
The concentrations of three heavy metals chromium (Cr), cadmium (Cd) and lead (Pb) were examined in water, sediment and green algae (Ulva lactuca); collected from six different stations at Pulicat Lake, which receives effluents from industries located in North Chennai Coastal region. Concentrations of Cd (64.21 microg g(-1)) and Cr (28.51 microg g(-1)) were found to be high in sediment, whereas in green algae concentration of Pb (8.32 microg g(-1)) was higher than water and sediment samples. The relative abundance of these heavy metals in U. lactuca and sediment were found to be in the order Cd>Cr>Pb, whereas in water the ratio was found to be Cr>Pb>Cd. The seasonal variations in Cd and Pb followed a similar pattern in both seaweeds and sediments, but not in water samples. Spearman correlation coefficient study showed no significant correlation in the concentration of metals in U. lactuca, water and sediment samples.  相似文献   

20.
为了研究我国桦甸油页岩65 t/h循环流化床锅炉的底渣和飞灰中重金属元素Cr、Cu、Pb和Zn的赋存状态及不同酸度条件下的浸出特性,分别进行了逐级提取实验和分批浸出的淋滤实验。逐级提取实验结果表明,这4种元素在底渣和飞灰中具有基本相当的赋存状态。硫化物结合态和稳定的残渣态是各元素的主要赋存状态,元素的潜在浸出能力大小表现为:PbCrCuZn,飞灰中各元素的潜在浸出能力大于底渣中的。浸出实验结果表明,元素的赋存状态决定了其浸提能力,浸提液的pH值对各元素浸出能力的影响不尽相同,各元素的浸出能力随浸提时间的延长都会趋于平衡,Cr和Pb的浸出浓度都高于地表水和饮用水的国家标准。  相似文献   

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