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1.
土法炼锌区大气沉降Pb、Zn、Cd及其对土壤质量的影响   总被引：6，自引：0，他引：6  
Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years but ceased in 2000, in Magu Town, Guizhou Province, China were selected to examine Pb, Zn, and Cd concentrations and their fractionation along a distance gradient from a zinc smelter, and to study the possible effects of Pb, Zn, and Cd accumulation on soil microorganisms by comparing with a reference soil located at a downwind distance of 10 km from the zinc smelter. Soils within 1.5 km of the zinc smelter accumulated high levels of heavy metals Zn (508 mg kg-1), Pb (95.6 mg kg-1), and Cd (5.98 mg kg-1) with low ratios of Zn/Cd (59.1--115) and Pb/Cd (12.4--23.4). Composite pollution indices (CPIs) of surface soils (2.52--15.2) were 3 to 13 times higher than the reference soils. In metal accumulated soils, exchangeable plus carbonate-bound fractions accounted for more than 10% of the total Zn, Pb, and Cd. The saturation degree of metals (SDM) in soils within 1.5 km of the smelter (averaging 1.25) was six times higher than that of the reference soils (0.209). A smaller soil microbial biomass was found more frequently in metal accumulated soils (85.1--438 μg C g-1) than in reference soils (497 μg C g-1), and a negative correlation (P < 0.01) of soil microbial biomass carbon to organic carbon ratio (Cmic/Corg) with SDM was observed. Microbial consumption of carbon sources was more rapid in contaminated soils than in reference soils, and a shift in the substrate utilization pattern was apparent and was negatively correlated with SDM (R = -0.773, P < 0.01). Consequently, dust deposited Pb, Zn, and Cd in soils from zinc smelting were readily mobilized, and weredetrimental to soil quality mainly in respect of microbial biomass.  相似文献   

2.
A slightly modified three-step sequential extraction procedure proposed by the Community Bureau of Reference (BCR) for analysis of sediments was successfully applied to soil samples. Contaminated soil samples from the lead and zinc mining area in the Mezica valley (Slovenia) and natural soils from a non-industrial area were analysed. The total concentrations of Cd, Pb and Zn and their concentrations in fractions after extraction were determined by flame or electrothermal atomic absorption spectrometry (FAAS, ETAAS). Total metal concentrations in natural soils ranged from 0.3 to 2.6 mg kg-1 for Cd, from 20 to 45 mg kg-1 for Pb and from 70 to 140 mg kg-1 for Zn, while these concentrations ranged from 0.5 to 35 mg kg-1 for Cd, from 200 to 10000 mg kg-1 for Pb and from 140 to 1500 mg kg-1 for Zn in soils from contaminated areas. The results of the partitioning study applying the slightly modified BCR three-step extraction procedure indicate that Cd, Pb and Zn in natural soils prevails mostly in sparingly soluble fractions. Cd in natural soils is bound mainly to Fe and Mn oxides and hydroxides, Pb to organic matter, sulphides and silicates, while Zn is predominantly bound to silicates. In contaminated soils, Cd, Pb and Zn are distributed between the easily and sparingly soluble fractions. Due to the high total Cd, Pb and Zn concentrations in contaminated soil close to the smelter, ! and their high proportions in the easily soluble fraction (80% of Cd, 50% of Pb and 70% of Zn), the soil around smelters represents an environmental hazard.  相似文献   

3.
肥料重金属含量状况及施肥对土壤和作物重金属富集的影响   总被引：56，自引：5，他引：56  
本文对肥料中重金属的含量状况以及施肥对土壤和农作物重金属累积影响的研究进展进行了系统分析和总结。过磷酸钙中锌（Zn）、 铜（Cu）、 镉（Cd）、 铅（Pb）含量高于氮肥、 钾肥和三元复合肥,有机-无机复混肥料中的Pb含量高于其他化肥。有机肥如畜禽粪便、 污泥及其堆肥中的重金属含量高于化肥,猪粪中的Cu、 Zn、 砷（As）、 Cd含量明显高于其他有机废弃物,鸡粪中铬（Cr）含量高;污泥和垃圾堆肥中Pb或汞（Hg）含量高。商品有机肥Zn、 Pb和镍（Ni）含量高于堆肥,Hg含量高于畜禽粪便。多数研究表明,氮磷钾配施与不施肥相比土壤Cd和Pb含量增加,施用有机肥比不施肥提高土壤Cu、 Zn、 Pb、 Cd含量。施用化肥对农作物重金属富集的影响不明确,而施用有机肥可提高作物可食部位Cu、 Zn、 Cd、 Pb 的含量,影响大小与有机肥种类、 用量、 土壤类型和pH以及作物种类等有很大关系。在今后的研究中应着重以下几个方面, 1）典型种植体系下土壤重金属的投入/产出平衡; 2）不同种植体系下长期不同施肥措施对土壤重金属含量、 有效性影响的动态趋势; 3）典型种植体系和施肥措施下土壤对重金属的最高承载年限; 4）现有施肥措施下肥料中重金属的最高限量标准。  相似文献   

4.
Total content of Fe, Mn, Zn, Cu, Pb, Cd, Ni and Co in soils irrigated with sewage effluent increased with increasing years of using sewage effluent in irrigation. Iron and Co applied to the soil from sewage effluent were immobilized mainly in unavailable form; Pb, Cd, and Ni in moderately available form; and Mn, Zn, and Cu in highly available form. The concentrations of Fe, Mn, Zn and Cu in tops of alfalfa and leaves of corn grown on these soils increased substantially with increased levels of available metal content of the soil, while those of other metals were little affected. As for orange, continuous increase in leaves metal content with time was found for Fe, Mn, Zn, Co and Cd. The concentrations of Cd, Co, Ni and Pb in corn grains and orange fruits were several times higher than normal, and this reduces their suitability for human consumption.  相似文献   

5.
污水灌溉对土壤浸提液元素浓度变化影响的田间试验研究   总被引：5，自引：1，他引：4  
土壤化学元素的变化趋势关系到污水灌溉农业的可持续性。该文通过田间试验,研究了冬小麦和夏玉米轮作条件下2种灌溉水质和3种灌水量对土壤浸提液元素浓度变化的影响。试验结果表明：在自然降雨条件下,大水量污灌增加土壤盐分而中、小水量污灌则降低土壤盐分。试验用污水不会导致土壤的次生碱化。土壤中的Ca、Mg、Fe和Zn含量在试验期间增加而P、Mn、Cu、Cd和Ni减小。大水量污灌增加土壤中的Na和B含量而小水量污灌则降低其含量;K的变化趋势与其相反。污灌可补充土壤中的作物营养元素K和P,但降低污水灌水定额可有效抑制盐分、B和Zn在土壤以及重金属元素在作物中的累积。  相似文献   

6.
采集草海湿地周边主要农作物可食部分及对应根系的土壤样品,分析测试了重金属Cd,Cr,Hg,Pb,As和Zn的含量,对比研究了土壤和作物中重金属污染水平及对重金属的富集能力。结果表明:土壤重金属元素Zn,As,Cr平均含量未超过贵州省土壤元素背景值,其他3种重金属Pb,Cd,Hg平均值分别是背景值的1.24,1.44,7.5倍;与中国《食品中污染物限量》标准相比,除Hg平均含量超标外,蔬菜中As,Cr,Zn,Cd和Pb平均含量处在可接受范围内。6种重金属的单因子污染指数的高低依次是Hg > Pb > Cd > As > Cr > Zn,葱和萝卜处于安全水平,其余农作物处于警戒线;不同种类作物中重金属富集特征差异较大,菠菜对As,Cd,Hg,Pb的富集系数比其余作物高,萝卜叶对Cr和Zn的富集能力较强,重金属Cr富集系数最低的是玉米,Zn和Hg富集系数最低的是萝卜根,Cd和Pb富集系数最低为马铃薯,As富集能力最低的为白菜。  相似文献   

7.

Purpose  

We investigated the chemical fractions of Zn, Cd and Cu in soils collected from positions at different distances from a copper smelter and studied the relationships between distribution patterns of Zn, Cd and Cu, fractions and soil organic carbon (SOC), especially “black carbon” (BC), in contaminated soils. The relationships between soil particle size and concentrations of Zn and Cd in contaminated soil were also examined.  相似文献   

8.
为了研究珠三角滩涂围垦农田土壤和农作物重金属污染状况,采集了广州南沙、中山一带围垦农田农作物及其根际土壤样品,测定重金属的质量分数。结果表明,围垦农田土壤样品中Cu、Ph、Cd、Ni、Cr和Zn含量均大于广东省相应土壤环境背景值,其中Cu（56．06mg·kg^-1）、Pb（48．30mg·kg^-1）、Cd（0．72mg·kg^-1）、Ni（41．15mg·kg^-1）、Cr（115．1mg·kg^-1）和Zn（200．1mg·kg^-1）分别为背景值的3．30、1．34、12．82、2．26、2．28和4．23倍。与《土壤环境质量标准》（GB15618-1995）中Ⅱ级标准（pH〈6．5）比较,土壤样品中Cu、Cd、Ni和Zn的超标率分别为73．7％、88．6％、59．6％和28．9％。以GB15618-1995中Ⅱ级标准为评价标准,采用Nemerow指数法进行评价,土壤重金属平均综合污染指数为1．86,属3级轻污染。与《食品中污染物限量》（GB2762-2005）等相关标准比较,农作物中Cu、Pb、Cd、Ni、Cr和Zn含量的样品超标率分别为0、28．9％、2．6％、48．3％、12．3％和6．1％。由此可见,珠三角滩涂围垦农田土壤和农作物重金属污染问题已经比较突出,土壤污染以Cd为主,而农作物污染则以Ni、Ph、Cr为主。  相似文献   

9.
The effect of long-term irrigation with untreated sewage effluents from Mexico City on soil properties and heavy metal adsorption behaviour of soils at Irrigation District 03 in the Mezquital Valley, Central Mexico, was studied. General soil parameters of 25 samples from Ap-horizons of Mollic Leptosols and Eutric Vertisols taken at sites which have been under irrigation for different periods of time were compared with samples from fields under rainfed agriculture. The adsorption of Pb, Cd, Cu and Zn was analysed in 8 selected samples by batch experiments. The long-term irrigation of soils with untreated sewage effluent has increased the contents of total (TOC) and dissolved (DOC) organic carbon in Ap-horizons of Leptosols and Vertisols, and diminished the contents of manganese oxides in Vertisols. This influences the heavy metal adsorption behaviour of both soils, since DOC enhances metal solubility at low loading rates and TOC improves metal adsorption capacities at high loading rates. The possibility of an increase in the chloride content in soils due to wastewater irrigation and its relation to higher Cd mobility are discussed, as is the importance of humus balance control through oriented management practices in order to minimize heavy metal mobility in soils, which have been under irrigation with wastewater during long periods.  相似文献   

10.
The cereal crops (barley -Hordeum vulgare L., maize -Zea mays L., wheat -Triticum vulgare L.) were grown in a greenhouse using a sandy soil type treated with various doses of cadmium carbonate (salt), copper carbonate (malachite), lead carbonate (cerussite), and zinc carbonate (smithsonite), added jointly. The following levels of these metals were used: Cd ? 5, 10, 50μg g?1 soil; Cu and Pb - 50,100, 500 μg g?1 soil; Zn-150, 300, 1500 μg g-1 soil. Sequential extraction was adopted to partition the metals into five operationally-defined fractions: exchangeable, carbonate, Fe-Mn oxides, organic, and residual. The residual was the most abundant fraction in the untreated (control) soil for all the metals studied (50 to 60% of the total metal content). The concentrations of exchangeable Cd, Cu, Pb, and Zn were relatively low in untreated soil but increased (over the three year period) in treated soils for Cd, Zn, and Cu, whereas only small changes were observed for Ph. This experiment showed a significant increase in Cd, Zn, and Cu in tissue of plants grown on the treated soil, but a non-significant change in plant tissue with respect to Pb concentration.  相似文献   

11.

Purpose

Water management has a strong influence on Cd solubility in agricultural soils, affecting Cd uptake in crops. In the process, sulfur interaction with other metals such as zinc may play an important role. A pot experiment was carried out to investigate the effects of water management coupled with zinc and sulfate amendment on Cd uptake by the leafy vegetable amaranth with a strong Cd accumulation tendency in its edible parts.

Materials and methods

The soils were amended with Cd, Cd+SO4 and Cd+SO4+Zn with no amendment as control. Then, the soils were flooded for 1 month, after which amaranth was grown with soil kept saturated (wet cultivation). In the succeeding planting, soils were tilled to aeration condition under which amaranth was grown again (dry cultivation). Soil and crop samples were collected and analysed for various parameters.

Results and discussion

The readily exchangeable quantities of Cd and Zn in the soil decreased under wet cultivation, increasing again under dry cultivation but to levels lower than those in the initial soil. Wet cultivation enhanced plant Cd concentration but reduced Zn accumulation compared to dry cultivation. Zn bioavailability was strongly affected by soil water status but failed to reduce Cd uptake by amaranth. Irreversible or slowly reversible changes occurred in Cd and Zn solubility and phytoavailability as soil water-saturated status was altered by periodic flooding events.

Conclusions

Dry cultivation with lower soil water content ensured high production with low Cd in the edible part of this leaf vegetable and so remains the recommended irrigation regime.
  相似文献   

12.
This study evaluated cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) sorption characteristics of three tropical soils. Data obtained conformed to Freundlich sorption model and the S-shaped isotherm curve. Sorption efficiency of Zn and Pb were highest in alkaline soil while slightly acid soil had the highest Cd and Cu sorption efficiency for monometal sorption. In competitive sorption, metals were more sorbed in slightly acid soil while the least efficiency was recorded in acid soil. Distribution coefficient; Kd (average across soil types) in monometal sorption followed the order: Pb > Zn > Cd > Cu. For competitive sorption, the order was Zn > Pb > Cu > Cd. When in competition, Cd was preferentially sorbed in slightly acid and alkaline soils and Zn for acid soil. Conclusively, lead is more in equilibrium solution when in competition with Cd, Zn and Cu making it potential agent of soil and groundwater pollution.  相似文献   

13.
Elevated concentrations of potentially toxic trace elements in agricultural soils contribute to soil pollution affecting food quality and safety. We assessed pollution levels in agricultural systems, lowland rice (LL) and highland cash crops (HL), by comparing with non-agricultural soils (NA). Correlation analysis and principal component analysis (PCA) were performed, and geo-accumulation index (Igeo) and pollution loading index (PLI) were calculated. Zinc in LL, and Cd in LL and HL, were significantly higher than in NA. The Igeo values of cooper (Cu), lead (Pb), nickel (Ni), zinc (Zn), and cadmium (Cd) ranged from uncontaminated to moderately contaminated (Class 0 to 2) for LL, HL, and NA. Overall, trace element levels were categorized as unpolluted based on PLI. Soil properties significantly correlated with Cu, Pb, Ni, and Zn concentrations but not with Cd. Based on PCA, sources of origin for Cu, Pb, Ni, and Zn were lithogenic, while the sources for Cd was anthropogenic in the studied agricultural soils.  相似文献   

14.
使用海泡石、磷酸二氢钙、钙镁磷肥、氧化钙和氧化镁等土壤改良剂及其组合,对湖南省某铅锌矿冶炼厂附近的重金属污染土壤进行了稳定化修复试验,利用BCR连续提取法进行形态分析,并进行稳定化效果的评价。结果表明,各改良剂组合均能够有效改变土壤中Zn、Cd和Pb的形态分布,弱酸提取态含量的减少率分别为Zn:17.03%~83.13%,Cd:45.03%~99.17%,Pb:54.05%~99.44%,降低重金属的不稳定形态和生物可利用性,稳定化效果显著。改良剂对Zn元素的稳定化效果影响程度为:钙镁磷肥+氧化钙钙镁磷肥+氧化镁钙镁磷肥海泡石+磷酸二氢钙海泡石;对Cd元素的稳定化效果影响程度为:钙镁磷肥+氧化钙钙镁磷肥+氧化镁钙镁磷肥海泡石+磷酸二氢钙海泡石;对Pb元素的稳定化效果影响程度为:海泡石+磷酸二氢钙钙镁磷肥+氧化镁钙镁磷肥+氧化钙钙镁磷肥海泡石。该复合污染土壤中,Zn、Cd、Pb稳定效果最优处理为10%钙镁磷肥+5%氧化钙组合。  相似文献   

15.
The status of essential and potentially toxic trace elements in soils and crops can be affected by long-term fertilization practices. This study aimed to investigate changes in peanut (Arachis hypogaea L.) yield and kernel quality, and changes in copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) concentrations in soil and peanut kernels after 16 years of continuous cropping with different fertilization treatments. Five fertilization treatments were applied at a red soil site in Southeast China:chemical fertilizer (F) containing nitrogen, phosphorus, and potassium, F + trace elements (FT), pig manure (M), M + effective microorganisms (MB), and MB + trace elements (MBT). Properties of soil and pig manure, heavy metal contents in soil and peanut kernels, and the compositions of amino and fatty acids in kernels were determined. Application of pig manure significantly increased peanut biomass, kernel yield, and crude protein and total amino acid contents in kernels, but led to higher amounts of Cu, Zn, and Cd in soil and higher amounts of Zn and Cd in peanut kernels compared with that of chemical fertilizer. There should be greater concern about potential kernel Cd and Zn contaminations resulting from long-term application of pig manure contaminated with potentially toxic metals as an organic fertilizer.  相似文献   

16.
Sterckeman  T.  Douay  F.  Proix  N.  Fourrier  H.  Perdrix  E. 《Water, air, and soil pollution》2002,135(1-4):173-194
Ag, As, Bi, Cd, Co, Cr, Cu, Hg, In, Ni, Pb, Sb, Se, Sn,Tl, Th, U and Zn contamination of cultivated surfacehorizons has been assessed around two lead and zincsmelters in the North of France. The verticaldistribution of Ag, As, Bi, Cu, Hg, Se, Sb and Tl inthe soils has also been examined. The soils around thelead and zinc smelter at Noyelles-Godault arecontaminated by Ag, As, Bi, Cd, Cu, Hg, In, Ni, Pb, Sb,Se, Sn, Tl and Zn. The original concentration in themost contaminated soils may be multiplied by a factorof around 2 to 100, according to the element. Cadmium,Pb and Zn are the most abundant contaminants. The Pband Zn concentrations are correlated to those of theother contaminants, with the exception of Se. Aroundthe Auby zinc smelter, there is a contamination by thesame elements, but in different proportions, inaddition to Cr contamination. Contamination by Se canreach a depth of around 1 m, whereas contamination byAg, As, Bi, Cu, Hg, Sb and Tl is confined to the top 30cm. Although the contaminant content in most soilsdepends on the distance from the plant, Secontamination would appear to vary to a greater extentaccording to the physico-chemical soil conditions.  相似文献   

17.
九华铜矿重金属环境污染状况研究   总被引：1，自引：0，他引：1  
选择江苏九华铜矿区,对其周边土壤和作物的重金属污染状况进行了研究.结果发现,约有一半的采样点土壤全Cu含量超过我国土壤环境质量三级标准(400 mg/kg),其DTPA提取态Cu含量的平均值为117 mg/kg.通过对矿区土壤重金属间的相关分析表明,土壤Cu与Zn、Pb、Cd、Co之间呈极显著的正相关关系(p＜0.01),而与Cr、Ni无显著相关,说明了该铜矿区土壤还伴有外源Zn、Pb、Cd、Co的污染.土壤复合污染指数(PI)＞1.0的土壤样品占57.3%.矿区周围作物可食部位Cu、Zn、Pb、Cd和Cr的含量均较高.  相似文献   

18.
The fate of airborne metal pollutants in soils is still relatively unknown. We studied the incorporation of such airborne metal pollution in two soils under long-term permanent pasture (PP) and conventional arable land (CA). Both soils were located at an almost equal distance from a former zinc smelter complex and developed under comparable pedogenetic conditions. Profiles of total concentrations of Zn, chosen as a mobile, and Pb as a little- or non-mobile element, were examined and compared with macro- and micromorphological soil characteristics (soil colour, biological activity). The two soils showed different profiles of total Zn and Pb concentrations, with a marked decrease of concentrations of both elements under the plough layer in CA, whereas the decrease was more progressive in PP. However, the stocks of Zn and Pb for the 1-m soil profiles of CA and PP were comparable. Correlation of Zn and Pb concentration at different depths with total Fe contents and comparison with estimated data for the local geochemical background (LGCB), suggests transport of Zn from the surface to depth in CA and PP, and Pb movement in PP. In CA, 53% of Zn and 92.5% of Pb stocks derived from airborne metal pollution were located at depths < 26 cm. In PP, only 40% of Zn and 82% of Pb, derived from airborne pollution, were found in the A11 and A12 horizons (< 26 cm), the remaining 18% of the Pb stock being incorporated until 50 cm depth; one-third of total Zn stock ascribed to airborne pollution was found at depths > 50 cm. Studies of the composition of gravitational water collected in soils from the same study area suggest two mechanisms for metal movement. First, mobile metal ions (Zn2+) move in the soil solution and are intercepted by iron-clay complexes in deeper soil horizons. Second, observed only in PP, simultaneous movement of Zn and Pb is ascribed to bioturbation by earthworms.  相似文献   

19.
In developing countries, farmers use effluent as a source of irrigation and nutrients and the government takes this practice as a viable option for disposal. Sewage samples have hazardous electrical conductivities (EC), sodium adsorption ratios (SARs), and residual sodium carbonate (RSC) for irrigation, but metals were close to upper permissible limits. The EC of saturated soil paste extract (ECe) ranged from 2.18 to 4.02 dS m–1 and soil SAR 7.72 to 16.00 in soils 0.2 m deep. Average cadmium (Cd), nickel (Ni), lead (Pb), zinc (Zn), and copper (Cu) in soils ranged from 0.02 to 0.13, 0.00 to 4.45, 2.27 to 4.57, 0.71 to 13.76, and 3.17 to 10.37 mg kg–1, respectively. Plants acquired metal contents greater than in raw sewage or soils. The wide biodiversity regarding metals in shoots of natural and planted vegetation that receives raw sewage is of practical significance. It seems imperative to study under controlled conditions various plants' metal tolerance and mechanisms of metal partitioning among plant parts.  相似文献   

20.
Along a heavy metal deposition gradient, caused by a Cu smelter, heavy metal concentrations, partitioning, and storage in forest and arable soils were examined. We sampled organic and mineral soil horizons (0—50 cm) at ten pairs of forest and arable sites derived from the same parent material. A-horizons were extracted with a seven-step sequence; O- and subsoil horizons were digested with strong acids (HNO3/HClO4). We found high concentrations of Cd (up to 17.38 mg kg—1 in the O horizons/up to 2.44 mg kg—1 in the A horizons), Cu (8437/415), Pb (3343/126), and Zn (1482/637) which decreased exponentially with distance from the smelter and with soil depth. The metal concentrations in the organic layers indicate that the average transport distance decreases in the order Cd > Zn > Pb > Cu. With regard to metal partitioning, NH4NO3- + NH4OAc-extractable forms in the A horizons were most affected by the deposition being more pronounced under forest. In the uppermost 50 cm of the four soils nearest to the smelter two to four times higher Cd, Cu, Pb, and Zn storages were found in forest than in arable soils. At greater distance, the higher deposition onto forest soils due to the scavenging effect of the canopy obviously was compensated by stronger leaching.  相似文献   

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