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1.
The structure and properties of oligotrophic peat, oligotrophic peat gley, and pyrogenic oligotrophic peat soils identified on a plot 0.5 km2 in area in the northeast of Sakhalin Island have been studied. The vertical distributions of physicochemical, chemical, and ecotoxicological parameters in the profiles of some bog soil groups have been considered. An increase in ash content, a less acid reaction, and a deficit of available nitrogen and potassium have been revealed in the upper horizons of pyrogenic soils. No accumulation of mobile heavy metals is manifested in the pyrogenic horizons of peat soils. Statistical parameters of the spatial variation in pHKCl and total acidity, as well as the contents of ash, available phosphorus, exchangeable potassium, ammonium and nitrate nitrogen, mobile heavy metals (Cr, Ni, Cu, Zn, Cd, Pb), and benzo[a]pyrene, have been calculated for the moss and sublitter horizons. The variation coefficients are 30–100% for most of the studied parameters and reach 100–200% for available phosphorus; ammonium nitrogen; and mobile Ni, Cu, Zn, and Cd. An increase in the content of benzo[a]pyrene, although without MPC exceedance, is noted in the moss of pyrogenic soils and the peat horizons untouched by fires.  相似文献   

2.
Eurasian Soil Science - The differences between eutrophic peat soils (Hypereutric Sapric Histosols) and peaty gleyzems (Eutric Histic Gleysols) 20 years after a forest-peat fire have been studied...  相似文献   

3.
The purpose of this study was to determine the degree of PAH contamination and the association of PAHs with metals in urban soil samples from Sevilla (Spain). Fifteen polycyclic aromatic hydrocarbons-PAHs (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, indeno[1,2,3-c,d]pyrene) and seven metals (Cd, Cr, Cu, Mn, Ni, Pb, Zn) have been evaluated in representative urban soil samples. Forty-one top soils (0–10 cm) under different land use (garden, roadside, riverbank and agricultural allotment) were selected. PAHs from soil samples were extracted by sonication using dichloromethane. The simultaneous quantification of 15 different PAH compounds were carried out by HPLC using multiple wavelength shift in the fluorescence detector. For qualitative analysis a photo diode-array detector was used. Metal (pseudo-total) analysis was carried out by digestion of the soils with aqua regia in microwave oven. The mean concentration of each PAH in urban soils of Sevilla showed a wide range, they are not considered highly contaminated. The results of the sum of 15 PAHs in Sevilla soils are in the range 89.5–4004.2 μg kg?1, but there seems not to be a correlation between the concentration of PAHs and the land use. Of the 15 PAHs examined, phenanthrene, fluoranthene and pyrene were present at the highest concentrations, being the sum of these PAHs about 40% of the total content. Although metal content were not especially high in most soils, there are significant hints of moderate pollution in some particular spots. Such spots are mainly related with some gardens within the historic quarters of the city. The associations among metals and PAHs content in the soil samples was checked by principal components analysis (PCA). The largest values both for ‘urban’ metals (Pb, Cu and Zn) and for PAHs were mainly found in sites close to the historic quarters of the city in which a heavy traffic of motor vehicles is suffered from years.  相似文献   

4.
Morphology and properties of medium-deep oligotrophic peat, oligotrophic peat gley, pyrogenic oligotrophic peat gley, and peat gley soils on subshrub-cotton grass-sphagnum bogs and in swampy larch forests of northeastern Sakhalin have been studied. Variation in the thickness and reserves of litters in the studied bog and forest biogeocenoses has been analyzed. The profile distribution and spatial variability of moisture, density, ash, and pHKCl in separate groups of peat soils have been described. The content and spatial variability of petroleum hydrocarbons have been considered in relation to the accumulation of natural bitumoids by peat soils and the technogenic pressing in the oil-producing region. Variation of each parameter at different distances (10, 50, and 1000 m) has been estimated using a hierarchical sampling scheme. The spatial conjugation of soil parameters has been studied by factor analysis using the principal components method and Spearman correlation coefficients. Regression equations have been proposed to describe relationships of ash content with soil density and content of petroleum hydrocarbons in peat horizons.  相似文献   

5.
Gravelly clay loamy and clayey soils developed from the derivatives of ultramafic rocks of the dunite-harzburgite complex of the Rai-Iz massif in the Polar Urals have been studied. They are represented by raw-humus pelozems (weakly developed clayey soils) under conditions of perfect drainage on steep slopes and by the gleyzems (Gleysols) with vivid gley color patterns in the eluvial positions on leveled elements of the relief. The magnesium released from the silicates with the high content of this element (mainly from olivine) specifies the neutral-alkaline reaction in these soils. Cryoturbation, the accumulation of raw humus, the impregnation of the soil mass with humic substances, gleyzation, and the ferrugination of the gleyed horizons are also clearly pronounced in the studied soils. Despite the high pH values, the destruction of supergene smectites in the upper horizons and ferrugination (the accumulation of iron hydroxides) in the microfissures dissecting the grains of olivine, pyroxene, and serpentine, and in decomposing plant tissues take place. The development of these processes may be related to the local acidification (neutralization) of the soil medium under the impact of biota and carbonic acids. The specificity of gleyzation in the soils developing from ultramafic rocks is shown in the absence of iron depletion from the fine earth material against the background of the greenish blue gley color pattern.  相似文献   

6.
The diversity of soils in the southwestern part of the Pacific coast of Russia (Primorie region) is discussed. Overall, 17 soil types belonging to 8 soil orders have been described in this region, and their morphology and properties have been studied. The diversity of plant communities, geomorphic conditions, and parent materials and relatively mild (as compared with other parts of the Far East region of Russia) specify the great variability of soil cover patterns. Low sea terraces are occupied by various peat, organo-accumulative, and gley soils; poorly drained medium-high terraces are the areas of various dark-humus and darkhumus gleyed soils. Typical and gleyic dark-humus podbels, dark-humus, and dark-humus gleyed soils formed on the high sea terraces. Residual elevations are occupied by brown forest (burozemic) soils, including typical burozems, dark-humus burozems, and gleyic dark-humus burozems and by dark-humus podbels. Various alluvial, gleyic gray-humus, and mucky gley soils are developed on riverine plains. On general, darkhumus soils with the high (>10%) humus content predominate; the area of dark-humus podbels us estimated at about 20%, and the area of dark-humus burozems is about 12%. All the soils in this region are specified by increased acidity values. The exchangeable sodium content is often high in the upper soil horizons with maximum values (0.71–1.19 cmol(c)/kg) in the peat gleyzems, peaty dark-humus soils, mucky-gley soils, and eutrophic peat soils of sea terraces. The grouping of the soils with respect to their physicochemical and agrochemical properties is suggested.  相似文献   

7.
The distribution of pollutant heavy metals (Cu, Zn, Ni, Cd, and Pb) was determined in 11 acidic virgin peat profiles located along two transects moving away from a smelter plant in the Noranda region of Quebec. The levels of all five metals were found highest in the 0 to 15 cm layer at site near the smelter, and decreased progressively with the distance from the smelter, up to 42 km. Copper had the highest concentrations (5525 μg g?1) followed by Pb and Zn. The maximum levels of total metals built up in the peat surface near the smelter were high, approximately reaching the threshold limits for phytotoxicity in peat soils. The amounts of heavy metals moving down and accumulating in the anaerobic zone of the peat profiles were limited. The distribution and enrichment ratios in the profiles showed that Cu, Zn, and Cd would have relatively higher mobility than Pb.  相似文献   

8.
基于类型土壤的重金属元素形态分析研究相对较少,本研究以香港地区7个亚纲的土壤剖面为例,利用欧共体参比司(BCR)制定的三步连续提取法研究了类型土壤中重金属Cd、Cu、Pb和Zn的化学形态及其潜在环境风险。结果表明,Pb、Cd和Zn元素除残留态外,HOAc溶解态的比例也相对较高,但不同类型的土壤有所差别,而Cu元素则以残留态和可氧化态为主。在这7种类型土壤中,正常潜育土和湿润淋溶土中的重金属潜在环境风险相对较高,而在这4种重金属元素中,又以Pb元素的潜在环境风险最大。  相似文献   

9.
Contents and compositions of bitumoids, polycyclic aromatic hydrocarbons (PAHs), and free and retained hydrocarbon gases in soils along a transect at different distances from the local industrial source of atmospheric pollution with soot emissions have been studied. The reserves of PAHs progressively decrease when the distance from the source increases. Among the individual PAHs, the most significant decrease is observed for benzo[a]pyrene, tetraphene, pyrene, chrysene, and anthracene. On plowlands, the share of heavy PAHs—benzo[ghi]perylene, benzo[a]pyrene, perylene, etc.—is lower than in the forest soils. In automorphic soils of the park zone adjacent to the industrial zone, the penetration depth of four-, five-, and sixring PAHs from the atmosphere is no more than 25 cm. In soils under natural forest vegetation, heavy PAHs do not penetrate deeper than 5 cm; in tilled soils, their penetration depth coincides with the lower boundary of plow horizons. Analysis of free gases in the soil air revealed hydrocarbons only under forest. From the quantitative and qualitative parameters of the content, reserves, and compositions of different hydrocarbons, the following modification types of hydrocarbon status in the studied soils were revealed: injection, atmosedimentation–injection, atmosedimentation–impact, atmosedimentation–distant, and biogeochemical types.  相似文献   

10.
The association of Al, Mn, Fe, Ba, Zn, Cr, Ni, Co and Pb withsoil organic matter (SOM) was investigated in three Japanesesoils. Organically bound metals were assayed by elementalanalysis of a fraction extracted with acidified hydrogenperoxide (H2O2) and the humic acid extracted withalkaline reagent, from soil sampled at various depths of solums.A Dystric Cambisol showed higher extractability with acidifiedH2O2 for most of the metals than a Humic Andosol and an Orthic Acrisol. A Humic Andosol had more metals associated with humicacid than the other two soils.Cu showed high extractability with acidified H2O2 andalso significant association with humic acid, while Pb showedhigh extractability with acidified H2O2 but itsassociation with humic acid was relatively low among the metalsinvestigated. As humic acid is highly resistant to weathering,retention of Cu with SOM may last longer than that of Pb.The binding of metals with SOM probably has contributed to theaccumulation of some metals in organic-rich shallow horizons of soil. Such metals were Zn, Cu, Ni and Pb in a Dystric Cambisol,Cu in a Humic Andosol, and Pb and Cu in an Orthic Arisol.  相似文献   

11.
For evaluating present concentrations of heavy metals in soils, it is important to be able to determine natural or background soil concentrations. Here, we compare the content of 7 m HNO3-extractable and 0.2 m Na-EDTA-extractable fractions of cadmium (Cd), zinc (Zn), lead (Pb) and copper (Cu) in present day cultivated A horizons (Ap) under different land uses and 19 buried A horizons (Apb) that have been covered by 3300-year-old burial mounds. The buried A horizons represent a unique opportunity to evaluate background concentrations of heavy metals in top soil. Variations in background concentrations were mainly related to clay content. Using the grain size distribution of present-day topsoils (cultivated and forest/natural A horizons), the background concentrations were calculated and subtracted from observed concentrations prior to an evaluation of soil-type- and land-use-specific metal accumulation. All cultivated soils were significantly enriched with respect to Cd, Pb, Zn and Cu over the last 3300 years and all forest soils were enriched with Pb. The study highlights the importance of using appropriate reference material for assessing present-day metal concentrations and stocks.  相似文献   

12.
Abstract

The sorption of Cu and Zn on soils, as a function of pH, is important to an understanding of their mobility in the soil solution and their availability for plant nutrition. Copper and Zn sorption as a function of the pH were measured for six B horizons of two Orthic Humic Gleysols, two Orthic Humo‐Ferric Podzols, one Orthic Dystric Brunisol and one Orthic Sombric Brunisol. The results show that: 1) for the same amount of metal in solution and the same pH, more Cu is sorbed than Zn and 2) there is a maximum of sorption at or just above pH 5.00 and a large decrease as pH decreases.

During the pH‐dependent sorption of Cu and Zn on six B horizons of Quebec soils, it was found that ions were released into solution thus altering the charge generated by the soil at low pH and the sorption behavior of Cu and Zn. The solid phase most likely to control the level of ions in solution is believed to be the amorphous and oxide forms of Al and Fe. The dissolution of these metal oxide or hydrous oxide materials also releases cations adsorbed on, or occluded in, the amorphous material.  相似文献   

13.
Solubility and retention of heavy metals in soils Model experiments were carried out under oxidizing conditions with soil samples from surface and subsurface horizons of different composition in order to investigate the solubility and retention of Cu, Zn, Cd, and Pb in soils. The solubility of heavy metals is mainly determined by ad- and desorption processes and complexation reactions of organic and inorganic ligands. Precipitation and dissolution of definite heavy metal compounds do not seem to govern the solution concentration in soils. An exception may probably be the formation of lead phosphate and zinc silicate under specific reaction conditions. The main factors which determine solubility and retention of heavy metals are total amount (except the proportion incorporated in the silicate structure) of the different metals, soil reaction, content of mobilizing and immobilizing organic substances, content of pedogenic oxides and clay minerals, and kind and concentration of salts and inorganic ligands. The results of the model experiments are used together with the results of other authors and general physico-chemical data to give an interpretation of the solubility behaviour of heavy metals in soils. The relations between heavy metal solubility, availability and mobility and possible procedures for melioration of soils contaminated with heavy metals are discussed.  相似文献   

14.
Electron microprobe studies on soil samples with varying heavy metal contamination. 2. Contents of heavy metals and other elements in aggregations of humic substances, litter residues and charcoal particles EMA point analysis show that the organic matter constituents of heavy metal contaminated soils are highly enriched with heavy metals. The maximal trace element accumulation were for Cu up to 13,000 mg/kg, for Zn up to 48,000 mg/kg, for Cd up to 2,100 mg/kg and for Pb up to 193,000 mg/kg. The affinity for the accumulation of the different heavy metals in aggregations of humic substances can be described by the sequence Cu > Pb ? Cd > Zn ? Ni > Co. In very strongly acidified humic top soil horizons the Pb and Cd accumulation in the organic matter constituents is in competition with the accumulation in Fe and Mn oxides. The heavy metal contents (especially of Cu) of the organic matter are often correlated with the content of organically bound calcium. The EMA results also show that high heavy metal amounts occur in combination with Ca-accumulations in the epidermis and the outer bark parenchym of decayed roots. EMA point analysis of the interior of fungus sclerotias show that sclerotias can contain high amounts of heavy metals, in particular lead (up to 49,700 mg Pb/kg). From statistical results of EMA point analysis follows that lead and other heavy metals attached to humic substances are not only bound as metal organic complexes but also as organic metal phosphate complexes. Also charcoal particles of polluted soils contain high amounts of heay metals. The accumulation affinity is quite similar to that of humic substances.  相似文献   

15.
Differently directed and heterochronous cryogenic processes have contributed to the contrasting soil cover patterns and spatial heterogeneity of the properties of soils in hydromorphic ecosystems of the discontinuous permafrost zone of the northern taiga in Western Siberia. Frost heave and permafrost thawing within ecosystems of highmoor bogs have led to the development of specific cryogenic landforms, such as flat-topped and large peat mounds. A set of cryogenic soils is developed in these ecosystems; it includes different variants of cryozems, gleyzems (Cryosols), and peat soils (Histosols). The distribution of these soil types is controlled by the local topography and thawing depth, other factors being insignificant. Alternation of peat horizons of different types and ages, whirl-like patterns of horizon boundaries, considerable variations in the thickness of soil horizons, and inversions of soil horizons under the impact of frost cracking, frost heave, and cryoturbation are typical of the considered soils. Thawing depth is the most significant factor affecting the thickness of organic horizons, the soil pH, and the degree of decomposition of peat. As a result of the upward movement of bog ecosystems under the impact of frost heave, peat soils are subjected to considerable transformation: peat horizons undergo mineralization, and the thickness of organic horizons decreases; in some cases, eluvial–illuvial differentiation of the mineral horizons takes place, and peat podzols are developed. However, the opposite process of the return of the soils to the bog stage of pedogenesis with peat accumulation may take place in any time in the case of activation of thermokarst processes.  相似文献   

16.
Measurements taken for total petroleum hydrocarbons (TPHs), total organic carbon (TOC) and trace metals [vanadium (V), nickel (Ni), cadmium (Cd) and lead (Pb)] in 40 soil samples are used to delineate oil contamination levels and state of oil penetration in soils heavily contaminated with oil lakes in Al-Ahmadi and Burgan oil fields. All soil horizons in Al-Ahmadi profile contain very high concentrations of TPHs down to the depth interval 80–95 cm. In contrast, TPH contaminations are restricted to the upper 50 cm layer in the Burgan profiles, then drop sharply to natural background levels in subsequent soil horizons. A strong and positive relationship exists between the high TOC and TPH contents of the two profiles. The two soil profiles contain contaminations of V and Ni as well as high concentrations of Cd and Pb. Possible sources of these metals are oil contaminants from the lakes and/or deposited airborne oil fallouts. V/Ni ratios of the surface tar sludge and the soil horizons in the two profiles cannot be used in identifying terrestrial oil spills or as indicators of oil contamination in Kuwaiti soils.  相似文献   

17.
引黄灌区是我国重要的农业生产基地,其土壤重金属赋存状况直接关系到农业的可持续发展。本研究以黑岗口引黄灌区开封北郊稻麦轮作下农田土壤为研究对象,采集了耕作层(0~15 cm与15~30 cm)与剖面(0~100 cm)土壤样品,对其土壤剖面主要性质与重金属Pb、Cd、Cu和Zn的积累特征进行了分析。结果表明:(1)长期引黄灌溉及稻麦轮作下,开封北郊农业土壤主要性质在剖面上表现出明显的分异特征:总有机碳(TOC)与全氮(TN)含量主要分布在耕作层土壤,而30 cm以下的土层其含量明显降低;全磷(TP)含量在各土壤层中无明显差异;在部分土壤剖面中CaCO3呈现出明显的淀积层。(2)耕作层(0~30 cm)土壤中重金属Pb、Cu、Zn的含量与研究区背景值相当,而Cd含量显著高于背景值。除少部分剖面含量超标外,Cd、Pb、Cu、Zn的平均含量均未超出WHO限值,且远低于我国农业土壤环境质量标准。因子分析源解析表明:引黄灌区土壤中Pb、Cu和Zn具有相似的来源和迁移特性,而Cd的来源和迁移特性具有特殊性,它可能与当地的化肥施用等农业活动有关。(3)土壤剖面中Cu和Zn具有明显的表聚现象,Pb的表聚作用不明显,而Cd在剖面各层土壤含量具有较大变异性,这与重金属的自身属性、土壤剖面性质和当地的耕作条件有较大相关性。(4)Cu和Zn在土壤剖面主要以有机结合态和残余态形式存在;Pb的残余态、有机态以及铁锰氧化态含量也较高,且Pb的全量与有机结合态含量百分比变化呈现出一定的相似性;而Cd具有较高的碳酸盐结合态和离子交换态,表明Cd在土壤中具有较强的移动性,预示Cd的潜在健康风险较高。  相似文献   

18.
Forest soil organic horizons from old and young plantations in the Alltcailleach Forest, N.E. Scotland were first sampled in 1949/50 and resampled in 1987. Copper, Pb and Zn in the soils were determined simultaneously on the original (stored) and the resampled soils. Overall mean Cu and Pb concentrations increased from 12.7 to 15.3 and 49.5 to 60.8 mg kg?1 between 1949/50 and 1987. Zinc concentrations decreased from 76.4 to 60.7 mg kg?1. Amounts of all 3 heavy metals increased because of increases in the thickness of organic horizons. Mean accumulation rates for Cu, Pb and Zn were 39.1, 186 and 114 g ha?1 yr?1, respectively. The rate of accumulation of Pb was significantly related to the rate of accumulation of organic matter. Copper and Zn concentrations were directly correlated with pH and inversely correlated with C/N ratio, whereas Pb was inversely correlated with pH and directly correlated with % C and C/N ratio. The more acidic soil organic horizons therefore contained higher concentrations of Pb and lower concentrations of Cu and Zn.  相似文献   

19.
Complexation of Cu, Pb, and Cd by hot water soluble humic substances II. The stability of the complexes Soxhlet extracts of terrestrial and underwater soils were used to determine polarographically the stability of heavy metal complexes. Stability constants were calculated using the law of mass action. They were independent of concentration at levels higher than 2 mg Cd or 5 mg Pb/g humic substance, respectively. For Cu, constants increased below 8 mg Cu/g. At pH values in the polarographic medium between 4 and 8, the stability of the Pb complexes increased markedly with increasing pH. In most cases this was also valid for the copper complexes, cadmium complexes were either not influenced by pH or stability maximum was obtained at about pH 5. Drying of the samples before extraction did not alter significantly complex stabilities. Complex stabilities increased with increasing degree of humification for oligotrophic, underwater soils and nutrient poor, low moor peat, but reduced horizons of eutrophic gyttjas exhibited lower stability values.  相似文献   

20.
The degree of soil contamination in the impact zone of the Solnechnyi Tin Ore Processing Plant in the Solnechnyi district of the Khabarovsk region was evaluated. It was shown that the air contamination by the waste products of the ore-processing plant is extremely high with respect to the concentrations of toxic dust and heavy metals. The maximum concentrations of these contaminants exceed the background values by 16–80 times. The bulk contents of Pb, Zn, Cu, As, and Hg in the upper soil horizons within the impact zone exceeded the maximum permissible concentrations and the background values by 2–90 times. Abnormally high concentrations of Zn, As, and Pb were observed not only in the surface 10–cm-thick soil layer but also in the underlying (10–20 cm) horizon. The soil contamination transformed the geochemical sequence of heavy metals typical of the background soils (Zn > Pb > As > Cu > Hg) into a new sequence (As > Pb > Cu > Zn > Hg). The statistical data proved that the intensity of the migration of the heavy metals in the soils decreases with a rise in the soil humus content and a drop in the soil acidity. This should be taken into account in the elaboration of soil-protective measures in the investigated region.  相似文献   

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