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1.
Effect of addition of organic residues on phosphorus release kinetics in some calcareous soils of western Iran 总被引:2,自引:0,他引:2
We investigated the effects on phosphorus (P) release of the addition of potato, wheat, and sunflower residues and fruit compost
to five calcareous soils. Residue was added at the rate of 20 g kg−1. After 2 months of incubation, P values in control and amended soils were used for kinetic studies and fractionated by a
sequential extraction procedure. The relative contribution of available P fraction (KCl-P) increased from 1.4% in control
soils to 1.8%, 1.9%, 2.2%, and 2.3% in soils amended by fruit, wheat, potato, and sunflower residue addition, respectively,
indicating that organic residues increased P in this fraction. In soils amended with different residues, the percentage of
Olsen-P released over 86-h successive extractions with 0.01 M CaCl2 ranged from 57.6% for fruit residue addition (average of five soils) to 60.5% for potato residue addition. The ability of
residues to release P depended on the soil properties, with 21.9 mg kg−1 (average of all residues) released to soil 2 and 77.4 mg kg−1 released to soil 4. Also residues behaved differently, with 31.5 mg kg−1 (average of five soils) released by fruit residues and 40.0 mg kg−1 released by sunflower residues. Release of P was best described by a parabolic diffusion model. The corresponding rate constant
(mg kg−1 h−1/2) for P release for amended soils, defined as the release rate averaged for five soils, was found to decrease in the order:
potato (2.73) > sunflower (2.61) > wheat (2.56) > fruit (2.50). The present study demonstrates that addition of residues improves
P availability of these calcareous soils by increasing extractable P and the release rate and could be an alternative, indigenous
source of P. However, the increase in P availability and the release rate following organic residue application suggests high
potential mobility to water sources. 相似文献
2.
In this study, we examined the movement of potassium (K) in columns of contaminated calcareous soils by sheep manure and ethylene
diamine tetraacetic acid (EDTA). Glass tubes, 4.9 cm in diameter and 40 cm in length, were packed with contaminated soils.
The resulting 20-cm long column of soil had a bulk density of 1.3–1.4 g cm−3. Columns were leached with distilled water, 0.01 M EDTA, 0.01 M CaCl2, and sheep manure extract solutions. The amounts of K leached varied considerably between different soils (sandy loam and
loamy sand) and leaching solutions. The amount leached with EDTA solution, varied from 7.2 to 66.7% of the extractable K when
20 pore volumes had passed through the column. The breakthrough curves of K in the EDTA and CaCl2 were approximately similar, indicating they have similar ability to displace K from these contaminated calcareous soils.
Thus, among leaching solutions application of EDTA and CaCl2 on contaminated soils might enhance the mobility of K and large amounts of K will be leached. 相似文献
3.
Nitrogen and phosphorus mineralization in sediments of Taihu Lake after the removal of light fraction organic matter 总被引:1,自引:1,他引:0
Chunxia Yang Shengrui Wang Xiangcan Jin Fengchang Wu 《Environmental Earth Sciences》2010,59(7):1437-1446
Mineralization of organic matter (OM) in sediment is crucial for biogeochemical cycle of nitrogen (N) and phosphorus (P) in
lake ecosystem. Light fraction OM (LFOM) is a reactive pool in sediment and is considered as labile fraction contributing
to N and P cycling. In our study, the effect of LFOM on the process and characteristics of N and P mineralization in sediments
of Taihu Lake were investigated with 77-day waterlogged incubation plus intermittent leaching at 27°C. Sediments from Yuantouzhu
(Y) and Gonghu (G) were used, which were removed the LF. Results indicated that the organic nitrogen mineralized ranged from
14.3 to 19.5% of total nitrogen (193.49–378.93 mg kg−1 sediment) and the organic phosphorus mineralized ranged from 5.7 to 7.9% of total phosphorus (19.86–60.65 mg kg−1 sediment). The heavily polluted sediment had a higher mineralization rate and net mineral-N and mineral-P than slightly polluted
sediment. LF stimulated the initial amounts of inorganic N and P and also can be the potential source for mineralization.
After the LFOM removal, the net mineral-N of Y and G decreased 116.47 mg kg−1 sediment and 48.03 mg kg−1sediment, respectively, and the net mineral-P decreased 2.67 mg kg−1sediment for Y and 4.82 mg kg−1sediment for G. Two models were used to fit the observed mineral-N data vs. incubation days using a non-linear regression
procedure: one is the effective cumulated temperature model, a thermodynamic model which assumes that N mineralization is
affected by temperature; the other is the single first-order exponential model, which is a dynamic model. Based on root mean
square error values for the two models, the effective cumulated temperature model made a better prediction of N mineralization
than the other model for all the four treatments. The single first-order exponential model underestimated N mineralization
during the first 14 days and the last 21 days, and overestimated it in the other days during the 77-day incubation. This indicated
that temperature was the primary factor influencing N mineralization and the amount of mineral-N were correlated significantly
with the effective cumulated temperature (T ≥ 15°C) and incubation time when waterlogged incubation plus intermittent leaching was used. 相似文献
4.
The Sarcheshmeh copper mine smelter plant is one of the biggest copper producers in Iran. Long-time operation of about 25 years
of the smelter plant causes release of potentially toxic heavy metals into the environment. In this paper, geochemical distribution
of toxic heavy metals in 28 soil samples was evaluated around the Sarcheshmeh smelter plant. Soils developed over the nonmineralized
and uncontaminated areas have an average background concentration of 41.25 mg kg−1 Cu, 26.6 mg kg−1 As, 12.7 mg kg−1 Pb, 0.9 mg kg−1 Sb, 1.9 mg kg−1 Mo, 1.7 mg kg−1 Sn, 0.2 mg kg−1 Cd, 0.15 mg kg−1 Bi, 235 mg kg−1 S and 73.4 mg kg−1 Zn, respectively. As a result of smelting process, the upper soil layers (0–5 cm) were polluted by Cu (>1,397 mg kg−1), Cd (>3.42 mg kg−1), S (>821 mg kg−1), Mo (>10.3 mg kg−1), Sb (>11.7 mg kg−1), As (>120.6 mg kg−1), Pb (>83.8 mg kg−1), Zn (>214.9 mg kg−1), and Sn (>3.7 mg kg−1), respectively. These values are much higher than the normal concentration of the elements in the uncontaminated soil layers.
The elemental values decrease with distance travelled away of the smelter plant, especially at minimum wind direction. Furthermore,
high contaminated values of Cu (8,430 mg kg−1), As (500 mg kg−1), Pb (331 mg kg−1), Mo (61 mg kg−1), Sb (56.2 mg kg−1), Zn (664 mg kg−1), Cd (17.2 mg kg−1), Bi (13.4 mg kg−1), and S (3,780 mg kg−1) were observed in the upper soil layers close to the smelting waste dumps. Sequential extraction analysis shows that about
270 mg kg−1 Cu, 28 mg kg−1 Pb, 50.33 mg kg−1 Zn, and 47.84 mg kg−1 As were adsorbed by Fe and Mn oxides. The carbonate phases include 151 mg kg−1 Cu, 28 mg kg−1 Pb, 25 mg kg−1 Zn, and 32.99 mg kg−1 As. Organic matter adsorbed 314.6 mg kg−1 Cu and 29.18 mg kg−1 Zn. 相似文献
5.
Evaluation of phosphorus leaching from contaminated calcareous soils due to the application of sheep manure and ethylenediamine tetraacetic acid 总被引:1,自引:0,他引:1
Organic amendment application to heavy metal contaminated soils may contribute to leaching of phosphorus (P). The objectives
of this study were to determine the influence of sheep manure and ethylenediamine tetraacetic acid (EDTA) on the P leaching
from a wide range of calcareous contaminated soils. Glass tubes, 4.9 cm diameter, and 40 cm long, were packed with contaminated
soil. The resulting 20 cm long column of soils had bulk density of 1.3–1.4 g cm−3. The columns were leached with distilled water, 0.01 M EDTA, 0.01 M CaCl2 or sheep manure extract (SME) solutions. The breakthrough curves for P were different and the amounts of P leached varied
considerably between different soils and leaching solutions. The amounts leached with SME were less than the amount added
through the SME, indicating that some P was retained by the soil, mainly due to preliminary sorption of organic ligands on
to the soil with the creation of new sorbing surfaces. The amount leached with EDTA solution varied from 9.9 to 46.3% of the
extractable P when 15 pore volumes had passed through the column. Low amounts of P were leached by 0.01 M CaCl2, which is likely to be due to the high concentration of soluble Ca used in the solution. Thus, among leaching solutions the
application of EDTA and SME on contaminated calcareous soils might enhance the mobility of P and large amounts of P will be
leached, leading to contamination of ground and surface waters. 相似文献
6.
Kanchan Wakadikar Avik Sil Niranjan Kolekar Shalini Tandon Rakesh Kumar 《Environmental Earth Sciences》2011,64(1):25-28
Drilling fluids are used for drilling natural gas, oil and water wells. These spill over into the surrounding soil at the
point of drilling, which may impair soil health. A laboratory investigation was carried out to determine the effect of non
aqueous drilling fluid (NADF) and synthetic base oil used with it on soil health as indicated by the dehydrogenase activity.
A non-sterile sandy loam soil was treated with different amounts of NADF and base oil at a rate of 800, 8,000 and 16,000 mg kg−1. Initially, reduction in dehydrogenase activity was observed, but it increased with the incubation time. On the 60th day
of incubation dehydrogenase activity in untreated control was 1.04 mg TPF g−1 h−1 whereas in the soil samples treated with NADF and the base oil (16,000 mg kg−1), the activity was 1.53 mg TPF h−1 and 1.90 mg TPF h−1, respectively, which was 72 and 82% more than in untreated control. Base oil-treated soil showed more dehydrogenase activity
than that observed with NADF. Both NADF and base oil stimulated the soil dehydrogenase activity. 相似文献
7.
We studied the mobility of silver, heavy metals and europium in waste from the Las Herrerías mine in Almería (SE Spain). The
most abundant primary mineral phases in the mine wastes are hematite, hydrohematite, barite, quartz, muscovite, anorthite,
calcite and phillipsite. The minor phase consisted of primary minerals including ankerite, cinnabar, digenite, magnesite,
stannite, siderite and jamesonite, and secondary minerals such as glauberite, szomolnokite, thenardite and uklonscovite. The
soils show high concentrations of Ag (mean 21.6 mg kg–1), Ba (mean 2.5%), Fe (mean 114,000 mg kg–1), Sb (mean 342.5 mg kg–1), Pb (mean 1,229.8 mg kg–1), Zn (mean 493 mg kg–1), Mn (mean 4,321.1 mg kg–1), Cd (mean 1.2 mg kg–1) and Eu (mean 4.0 mg kg–1). The column experiments showed mobilization of Ag, Al, Ba, Cu, Cd, Eu, Fe, Mn, Ni, Sb, Pb and Zn, and the inverse modelling
showed that the dissolution of hematite, hausmannite, pyrolusite and anglesite can largely account for the mobilization of
Fe, Mn and Pb in the leaching experiment. The mobility of silver may be caused by the presence of kongsbergite and chlorargyrite
in the waste, while the mobility of Eu seems to be determined by Eu(OH)3, which controls the solubility of Eu in the pH–Eh conditions of the experiments. The mineralogy, pH, Eh and geochemical composition
of the mine wastes may explain the possible mobilization of heavy metals and metalloids. However, the absence of contaminants
in the groundwater may be caused by the carbonate-rich environment of “host-rocks” that limits their mobility. 相似文献
8.
The Cu–Co–Ni Texeo mine has been the most important source of Cu in NW Spain since Roman times and now, approximately 40,000 m3 of wastes from mine and metallurgical operations, containing average concentrations of 9,263 mg kg−1 Cu, 1,100 mg kg−1 As, 549 mg kg−1 Co, and 840 mg kg−1 Ni, remain on-site. Since the cessation of the activity, the abandoned works, facilities and waste piles have been posing
a threat to the environment, derived from the release of toxic elements. In order to assess the potential environmental pollution
caused by the mining operations, a sequential sampling strategy was undertaken in wastes, soil, surface and groundwater, and
sediments. First, screening field tools were used to identify hotspots, before defining formal sampling strategies; so, in
the areas where anomalies were detected in a first sampling stage, a second detailed sampling campaign was undertaken. Metal
concentrations in the soils are highly above the local background, reaching up to 9,921 mg kg−1 Cu, 1,373 mg kg−1 As, 685 mg kg−1 Co, and 1,040 mg kg−1 Ni, among others. Copper concentrations downstream of the mine works reach values up to 1,869 μg l−1 and 240 mg kg−1 in surface water and stream sediments, respectively. Computer-based risk assessment for the site gives a carcinogenic risk
associated with the presence of As in surface waters and soils, and a health risk for long exposures; so, trigger levels of
these elements are high enough to warrant further investigation. 相似文献
9.
Hyperaccumulation of lead,zinc, and cadmium in plants growing on a lead/zinc outcrop in Yunnan Province,China 总被引:3,自引:0,他引:3
A field survey was conducted to identify potential hyperaccumulators of Pb, Zn or Cd in the Beichang Pb/Zn mine outcrop in
Yunnan Province, China. The average total concentrations of Pb, Zn, and Cd in the soils were up to 28,438, 5,109, and 52 mg kg−1, respectively. A total of 68 plant species belonging to 60 genera of 37 families naturally colonizing the outcrop were recorded.
According to metal accumulation in the plants and translocation factor (TF), Silene viscidula was identified as potential hyperaccumulator of Pb, Zn, and Cd with mean shoot concentrations of 3,938 mg kg−1 of Pb (TF = 1.2), 11,155 mg kg−1 of Zn (TF = 1.8) and 236 mg kg−1 of Cd (TF = 1.1), respectively; S. gracilicanlis (Pb 3,617 mg kg−1, TF = 1.2) and Onosma paniculatum (Pb 1,837 mg kg−1, TF = 1.9) were potential Pb hyperaccumulators. Potentilla griffithii (Zn 8,748 mg kg−1, TF = 1.5) and Gentiana sp. (Zn 19,710 mg kg−1, TF = 2.7) were potential Zn hyperaccumulators. Lysimachia deltoides (Cd 212 mg kg−1, TF = 3.2) was a potential Cd hyperaccumulator. These new plant resources could be used to explore the mechanisms of Pb,
Zn and/or Cd hyperaccumulation, and the findings could be applied for the phytoremediation of Pb, Zn and/or Cd-contaminated
soils. 相似文献
10.
Copper contamination in soils and vegetables in the vicinity of an abandoned copper mine in China was investigated. The Cu
concentrations of 93 soil samples ranged from 30.4 to 3,191 mg kg−1 soil for a mean of 816.8 mg kg−1 soil. Among 15 samples from a 0 to 20-cm soil layer used for the toxicity characteristic leaching procedure (TCLP) test,
the highest value of Cu-TCLP was 133.8 mg kg−1 soil and the TCLP values were positively correlated with the total Cu content of the soils. The sequential extraction of
soils in the 0–20-, 20–40-, and 40–60-cm soil layers showed that Cu existed mainly in the Fe–Mn oxide fraction, sulfide/organic
fraction, and residual fraction. The copper contamination of 21 species of vegetables from in situ sampling was also examined.
Cu concentrations in the edible portions of Brassica chinensis and Solanum melongena were higher than the FAO/WHO standard (40 mg kg−1 DW). The health risk of copper for local inhabitants from consuming these vegetables was assessed on the basis of the target
hazard quotient. Enriched concentrations of copper were also found in situ in eight cultivars of B. chinensis planted in the fields, with two levels of Cu concentration. The results showed that there is severe copper contamination
in this mine area, and the pollutant in soils show a high risk of leaching into the groundwater and diffusing through the
food chain. 相似文献
11.
Displacement studies on leaching of potassium (K+) were conducted under unsaturated steady state flow conditions in nine undisturbed soil columns (15.5 cm in diameter and
25 cm long). Pulses of K+ applied to columns of undisturbed soil were leached with distilled water or calcium chloride (CaCl2) at a rate of 18 mm h−1. The movement of K+ in gypsum treated soil leached with distilled water was at a similar rate to that of the untreated soil leached with 15 mM
CaCl2. The Ca2+ concentrations in the leachates were about 15 mM, the expected values for the dissolution of the gypsum. When applied K+ was displaced with the distilled water, K+ was retained in the top 10–12.5 cm depth of soil. In the undisturbed soil cores there is possibility of preferential flow
and lack of K+ sorption. The application of gypsum and CaCl2 in the reclamation of sodic soils would be expected to leach K+ from soils. It can also be concluded that the use of sources of water for irrigation which have a high Ca2+ concentration can also lead to leaching of K+ from soil. Average effluent concentration of K+ during leaching period was 30.2 and 28.6 mg l−1 for the gypsum and CaCl2 treated soils, respectively. These concentrations are greater than the recommended guideline of the World Health Organisation
(12 mg K+ l−1). 相似文献
12.
P. Conde Bueno E. Bellido J. A. Martín Rubí R. Jiménez Ballesta 《Environmental Geology》2009,56(5):815-824
Mercury (Hg) is one of the elements with increasing environmental significance. A total of 22 samples (soils, rocks and gels)
were collected along a 6 km transect around the Valdeazogues River valley in the southwest of the Iberian Peninsula (Almadén,
Spain). Samples were characterized by different soil types of depositional sequences associated with mining tailings, type
and system tracts: 15 surface soil samples included in the transect; 3 of a Haploxerept soil profile developed on slates;
2 of quartzite and slates rocks (reference rocks in the area). Moreover, two of a gel substance (in the lower tract of the
river). Soil samples were analyzed for Hg, Cu, Ni, Cr, V, Pb, Cd and As, as well as for organic matter, pH abrasion and calcium
carbonate content. All samples were collected from the Almadén mining district. The level of occurrence of the elements (especially
Hg) and the effect of some properties on its concentration distributions were investigated. The total mercury contents varied
in the range 7,315–3.44 mg kg−1. The mean concentration of total mercury in soils and rocks was 477.03 mg kg−1dry mass. This value is very high compared to the regional background value of other areas. Only rarely is it higher than
1%: in one sample (7,315 mg kg−1) it was almost eight times in comparison with the affected zones, with a high value of 1,000 mg kg−1. Significant differences between samples were found in the total content of mercury. A large percentage of the samples registered
detectable levels of V, Cr, Ni, Pb, As and Cu. Cd readings were below the detectable range for all samples tested. Cr mean
concentration was 216.95 mg kg−1 (minimun concentration 86, maximun 358); V mean concentration was 119.09 mg kg−1 (minimun concentration 69, maximun 1,209); As mean concentration was 51.24 mg kg−1 (minimun 13.3 and maximun 319.4); Ni mean concentration was 45.64 mg kg−1 (minimun concentration 21.2 and maximun 125.6); Cu mean concentration was 33.25 mg kg−1 (minimun concentration 19.3 and maximun 135); Pb mean concentration was 15.19 mg kg−1 (minimun 1.12 and maximun 1013). Metal distribution generally showed spatial variability ascribed to significant anthropogenic
perturbation by mining tailing type. Hg showed vertical profile characterized by surface enrichment, with concentrations in
the upper layer (93.7–82.2 mg kg−1 in front of 3.4 of the rock value) exceeding, in several occasions, the background value. The results obtained denote a potential
toxicity of some heavy metals in some of the studied samples. Water-soluble mercury could enter the aquatic system and accumulate
in sediments. Mercury and other heavy metals contamination depended on the duration and intensity of mining activities. 相似文献
13.
Speciation and phytoavailability of heavy metals in sediments in Nanjing section of Changjiang River 总被引:3,自引:1,他引:2
Heavy metal pollution and their fractionations in the sediments of Changjiang River in Nanjing Reach was monitored for cadmium
(Cd), lead (Pb), zinc (Zn), chromium (Cr), and copper (Cu). Moreover, the biological enrichment of metals by riverine plants
was studied. The results demonstrated there were highly significant variations among different sampling stations for the concentrations
of tested metals. The highest range was for Cu (38.8–120.4 mg kg−1), followed by Cr (74.4–120.0 mg kg−1), Zn (80.9–121.1 mg kg−1), Ni (26.0–55.5 mg kg−1), Pb (15.8–46.7 mg kg−1) and Cd (0.28–0.48 mg kg−1). Cd was the element with highest biological enrichment factor (BEF). The highest BEF of Cd in Erigeron bonariensis reached 3.0, indicating a significant Cd enrichment in this aquatic plant. In addition, 60% of Cd was found in reducible
fraction and exchangeable and acid-soluble fraction, which was consistent with its high mobility. The consistency of Cd fraction
in sediment and suspended particle indicated they came from the same source. Accumulated Cd concentration calculated according
to the release curve showed significant relativity with the total Cd concentration in the sediment. 相似文献
14.
Physiological responses and metal accumulation in Vallisneria spiralis L. exposed to copper and cadmium contaminated sediment were examined at different metal concentrations and the influence
of humic acids on copper and cadmium accumulation was also studied. The plants of V. spiralis accumulated high amount of copper and cadmium. The maximum accumulation of 396 and 114 mg kg−1 DW copper were found in the roots and shoots, respectively, at 614 mg kg−1 DW after 21 days’ copper exposure; they were 63.8 and 48.0 mg kg−1 DW for cadmium at 88.69 mg kg−1 DW. The plants showed decrease in chlorophyll content with the increasing concentration of copper/cadmium in sediment. With
addition of humic acids from 3.09 to 7.89 g kg−1 DW, both copper and cadmium accumulation in V. spiralis were significantly inhibited (p < 0.01). The cadmium concentrations of roots and shoots of plant decreased 26.4–50.3 and 14.3–33.0% under cadmium treatments,
respectively; copper accumulation decreased much more with 44.0–77.0 and 35.0–62.7%, respectively. It was concluded that V. spiralis appeared to be an ideal candidate for the phytoremediation of copper and cadmium polluted sediments, and humic acids had
an important role in regulating copper and cadmium bioavailability and toxicity in sediments. 相似文献
15.
Guo-Ping Wang Xiao-Fei Yu Jian Wang Hong-Mei Zhao Kun-Shan Bao Xian-Guo Lu 《Environmental Earth Sciences》2011,62(1):207-216
The rare earth elements (REEs) in the sediments of the Xianghai wetlands were measured by inductively coupled plasma spectrometry.
The REEs accumulation rates in two sedimentation cores derived from the riparian and depressional marshes were determined
by 210Pb method. The results showed that REEs concentrations in the Xianghai wetland sediments (∑REEs, 116 mg kg−1) were lower than the corresponding values in Chinese soils (181 mg kg−1) and river sediments (∑REEs, 158–191 mg kg−1). Under alkaline conditions (with pH, 8.2–10.3), the light REEs were more enriched than the heavy REEs. Cerium is the predominant
element, and accounts for 30–33% of the total REEs. REEs in the depressional marsh sediments were relatively high (∑REEs,
127 vs. 104 mg kg−1), especially light REEs contents. A significantly positive correlation was found between the neighboring elements except
Pr and Dy. The different types of vertical distribution of REEs between the riparian and the depressional marsh can partly
result from long-term differing hydrological regimes. Generally, depressional marsh had accumulated much more REEs than riparian
marsh (the mean accumulation rates of ∑REEs, 102.98 vs. 48.89 μg cm−2 year−1). 相似文献
16.
Heavy metal concentrations and their possible sources in paddy soils of a modern agricultural zone,southeastern China 总被引:5,自引:0,他引:5
In a typical modern agricultural Zone of southeastern China, Haining City, 224 topsoil samples were collected from paddy fields
to measure the total concentrations of copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), mercury (Hg), arsenic
(As) and cobalt (Co). The total concentrations ranged from 15.30 to 78.40 mg kg−1 for Cu, 20.10 to 41.40 mg kg−1 for Pb, 54.98 to 224.4 mg kg−1 for Zn, 0.04 to 0.24 mg kg−1 for Cd, 54.90 to 197.1 mg kg−1 for Cr, 0.03 to 0.61 mg kg−1 for Hg, 3.44 to 15.28 mg kg−1 for As, and 7.17 to 19.00 mg kg−1 for Co. Chemometric techniques and geostatistics were utilized to quantify their spatial characteristics and define their
possible sources. All eight metals had a moderate spatial dependency except that Pb had a strong spatial dependency. Both
factor analysis and cluster analysis successfully classified the eight metals into three groups or subgroups, the first group
included Cu, Zn and Cr, the second group included Cd, As and Co, and the last group included Pb and Hg. The Cu, Zn and Cr
concentrations in majority samples were higher than their local background concentrations and they were highly correlated
(r > 0.80), indicating that they had similar pollution source and anthropic factor controlled their spatial distribution; the
Cd, As and Co concentrations in majority samples were lower than their local background concentrations, indicating that the
source of these elements was mainly controlled by natural factors; the mean concentration of Pb exhibited generally low level,
close to its local background concentration, the Hg concentration in about half of samples was higher than its local background
concentration, and they were poor correlated with the other metals, indicating that the source of Pb and Hg was common controlled
by natural factor and anthropic factor. 相似文献
17.
Trace metals (Cd,Pb, Cu,Zn and Ni) in sediment of the submarine pit Dragon ear (Soline Bay,Rogoznica, Croatia) 总被引:1,自引:0,他引:1
Vertical profiles of trace metal (Cd, Pb, Zn, Cu, Ni) concentrations, organic matter content, carbonate content and granulometric
composition were determined in two sediment cores from the submarine pit Dragon Ear (Middle Adriatic). Concentrations of the
analyzed metals (Cd: 0.06–0.12 mg kg−1, Pb: 28.5–67.3 mg kg−1, Zn: 17.0-65.4 mg kg−1, Cu: 21.1–51.9 mg kg−1, Ni: 27.8–40.2 mg kg−1) were in usual range for Adriatic carbonate marine sediments. Nevertheless, concentrations of Cu, Zn, and especially Pb in
the upper layer of sediments (top 12 cm) were higher than in bottom layer, while Cd and Ni concentration profiles were uniform.
Regression analysis and principal component analysis were used to interpret distribution of trace metals, organic matter and
carbonate content in sediment cores. Results of both analysis showed that concentrations of all trace metals in the core below
the entrance to the pit were significantly positively correlated with organic matter and negatively correlated with carbonate,
while in the core more distant from the entrance only Pb showed significant positive correlation with organic matter. Obtained
results indicated that, except for lead which was enriched in surface sediment, in the time of sampling (before the building
of the nautical marina) investigated area belonged to unpolluted areas. 相似文献
18.
Spatial variability of heavy metals in soils across a valley plain in Southeastern China 总被引:1,自引:0,他引:1
An investigation was carried out to survey the magnitude and spatial distribution of heavy metals, as well as their relation
with soil series, in a valley plain in Southeastern China. Soil was sampled at 159 sites by combining a squared grid and nested
sampling strategies along the transect perpendicular to the Qujiang River in Zhejiang Province, China. Total concentrations
of six metals, namely Cu, Fe, Mn, Ni, Pb and Zn, were measured. Classical statistics and geostatistics were used to quantify
their spatial characteristics. There was a considerable variation in many of these parameters. The total concentrations ranged
from 6.8 to 29.3 mg kg−1 for Cu, 6,784 to 18,678 mg kg−1 for Fe, 94 to 385 mg kg−1 for Mn, 6.1 to 20.3 mg kg−1 for Ni, 25.0 to 49.5 mg kg−1 for Pb, and 12 to 160 mg kg−1 for Zn. Pearson correlation coefficients among total metal concentrations and selected soil properties showed a number of
strong associations. By virtue of analysis of variance, a predominant influence of soil series on the spatial variability
of metal concentrations was observed. All metals were spatially correlated. The semivariograms of Cu, Fe, Mn, Ni and Zn were
dominated by short range correlation (600 or 700 m), and that of Pb by long range (1200 m). Block kriging maps of total metal
concentrations and soil properties showed strip distributions, perpendicular to the river, in the manner similar to the soil
series. Principal component analysis was run to identify common distribution patterns of heavy metals and soil properties.
These results illustrate that soil series information of valley plain may be useful for developing management zones for site-specific
agriculture. 相似文献
19.
Geochemical and statistical approach to evaluate background concentrations of Cd,Cu, Pb and Zn (case study: Eastern Poland) 总被引:2,自引:2,他引:0
Wojciech Zgłobicki Lesia Lata Andrzej Plak Marek Reszka 《Environmental Earth Sciences》2011,62(2):347-355
An attempt was made to evaluate background concentrations of Cd, Cu, Pb and Zn by means of geochemical and statistical approach.
As many as 753 samples taken from 51 profiles located in Eastern Poland were analysed. For the estimation of geochemical background
values, direct geochemical methods and a statistical analysis for the whole population of samples were applied. Average values
of heavy metal concentration in loess sediments (bedrock) as well as in profiles not affected by human activity were measured.
The iterative 2σ technique and calculated distribution function were chosen as statistical methods. The resulting values (background
concentrations range) were as follows: Cd 0.5–0.9 mg kg−1, Cu 5–16 mg kg−1, Pb 12–26 mg kg−1 and Zn 31–47 mg kg−1. All the methods applied gave similar results. The highest deviation of the background was noted for Cu and the lowest for
Zn. The lowest values of background were obtained for loess sediments and the highest in the case of the multiple 2σ method. 相似文献
20.
Fluorine is one of the many environmental harmful elements released by volcanic activity. The content of total oxalate-extractable
and water-extractable fluorine was determined in 96 topsoils of three active volcanic systems of southern Italy (Mt Etna,
Stromboli and Vulcano). Total fluorine (F) content (F
TOT) ranges from 112 to 7,430 mg kg−1, F extracted with oxalate (F
OX) ranges from 16 to 2,320 mg kg−1 (2–93% of F
TOT) and F extracted with distilled water (
) ranges from 1.7 to 159 mg kg−1 (0.2–40 % of F
TOT). Fluorine in the sampled topsoils derives both from the weathering of volcanic rocks and ashes and from the enhanced deposition
due to volcanic gas emissions either from open-conduit passive degassing (Mt Etna and Stromboli) or from a fumarolic field
(Vulcano). Fluorine accumulation in the studied soils does not generally present particular environmental issues except for
a few anomalous sites at Vulcano, where measured contents could be dangerous both for vegetation and for grazing animals. 相似文献