共查询到20条相似文献,搜索用时 138 毫秒
1.
Munendra Singh 《Environmental Geology》2001,40(6):664-671
The Yamuna River sediments, collected from Delhi and Agra urban centres, were analysed for concentration and distribution
of nine heavy metals by means of atomic adsorption spectrometry. Total metal contents varied in the following ranges (in mg/kg):
Cr (157–817), Mn (515–1015), Fe (28,700–45,300), Co(11.7–28.4), Ni (40–538), Cu (40–1204), Zn (107–1974), Pb (22–856) and
Cd (0.50–114.8). The degree of metal enrichment was compared with the average shale concentration and shows exceptionally
high values for Cr, Ni, Cu, Zn, Pb and Cd in both urban centres. In the total heavy metal concentration, anthropogenic input
contains 70% Cr, 74% Cu, 59% Zn, 46% Pb, 90% Cd in Delhi and 61% Cr, 23% Ni, 71% Cu, 72% Zn, 63% Pb, 94% Cd in Agra. A significant
correlation was observed between increasing Cr, Ni, Zn, and Cu concentrations with increasing total sediment carbon and total
sediment sulfur content. Based on the Müller's geoaccumulation index, the quality of the river sediments can be regarded as
being moderately polluted to very highly polluted with Cr, Ni, Cu, Zn, Pb and Cd in the Delhi and Agra urban centres. The
present sediment analysis, therefore, plays an important role in environmental measures for the Yamuna River and the planning
of these city centres.
Received: 21 June 1999 · Accepted: 1 October 1999 相似文献
2.
The marine coastal sediments from Togo have been analysed for the trace elements Cd, Cr, Cu, Ni, Pb, Sr, V, Zn and Zr to
ascertain the geo-ecological impact of dumping of phosphorite tailings into the sea. Trace element concentrations ranged from
2–44 ppm for Cd, 22–184 ppm for Cu, 19–281 ppm for Ni, 22–176 ppm for Pb, 179–643 ppm for Sr, 38–329 ppm for V, 60–632 ppm
for Zn and 18–8928 ppm for Zr. Regional distribution of trace elements in the marine environment indicates that the concentrations
of Cr, Cu, Ni, Pb, V, Sr and Zn increase seawards and along the coastal line outwards of the tailing outfall, whereas Cd and
Zr showed reversed spatial patterns. Sorting and transport of phosphorite particles by coastal currents are the main factors
controlling the distribution of particle-bound trace metals in the coastal environment. The Cd, Sr and Zn concentrations decrease
with decreasing grain size in marine coastal sediments, whereas Cr, Cu, Ni and Zn concentrations increase with decreasing
grain size. Percolation and shaking experiments were carried out in laboratory using raw phosphate material and artificial
sea water. Enhanced mobilization of Cd from phosphorites by contact with the sea water was observed.
Received: 11 May 1998 · Accepted: 20 October 1998 相似文献
3.
Bo Peng Xiaoya Tang Changxun Yu Changyin Tan Chunyan Yin Guang Yang Qian Liu Kesu Yang Xianglin Tu 《Environmental Earth Sciences》2011,64(5):1455-1473
This paper reports a geochemical study of trace metals and Pb isotopes of sediments from the lowermost Xiangjiang River, Hunan
province (P. R. China). Trace metals Ba, Bi, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, Mo, Cd, Sn, Sb, Pb, Tl, Th, U, Zr, Hf, Nb and
Ta were analyzed using ICP-MS, and Pb isotopes of the bulk sediments were measured by MC-ICP-MS. The results show that trace
metals Cd, Bi, Sn, Sc, Cr, Mn, Co, Ni, Cu, Zn, Sb, Pb and Tl are enriched in the sediments. Among these metals, Cd, Bi and
Sn are extremely highly enriched (EF values >40), metals Zn, Sn, Sb and Pb significantly highly (5 < EF < 20), and metals
Sc, Cr, Mn, Co, Ni, Cu and Tl moderately highly (2 < EF < 5) enriched in the river sediments. All these metals, however, are
moderately enriched in the lake sediments. Geochemical results of trace metals Th, Sc, Co, Cr, Zr, Hf and La, and Pb isotopes
suggest that metals in the river sediments are of multi-sources, including both natural and anthropogenic sources. Metals
of the natural sources might be contributed mostly from weathering of the Indosinian granites (GR) and Palaeozoic sandstones
(PL), and metals of anthropogenic sources were contributed from Pb–Zn ore deposits distributed in upper river areas. Metals
in the lake sediments consist of the anthropogenic proportions, which were contributed from automobile exhausts and coal dusts.
Thus, heavy-metal contamination for the river sediments is attributed to the exploitation and utilization (e.g., mining, smelting,
and refining) of Pb–Zn ore mineral resources in the upper river areas, and this for the lake sediments was caused by automobile
exhausts and coal combustion. Metals Bi, Cd, Pb, Sn and Sb have anthropogenic proportion of higher than 90%, with natural
contribution less than 10%. Metals Mn and Zn consist of anthropogenic proportion of 60–85%, with natural proportion higher
than 15%. Metals Sc, Cr, Co, Cu, Tl, Th, U and Ta have anthropogenic proportion of 30–70%, with natural contribution higher
than 30%. Metals Ba, V and Mo might be contributed mostly from natural process. 相似文献
4.
Monsoon rain causes large scale sediment-water movement and reworking of sediments of the Ganga Plain which is one of the
largest fluvial systems on Earth. Geomorphology and drainage type combined with sedimentation processes play a substantial
role on dispersion and transport patterns of metals bound to sediments and soils. The study area of Kanpur-Unnao industrial
region in the Ganga Plain has been divided into five independent geochemical domains on the basis of sediment-geomorphic,
hydrological and geochemical characters. The monsoon hydrography and physico-chemical parameters (pH, conductivity) of the
river and urban drain waters play a prominent role in regulating the concentrations and behaviour of the metals in the aquatic
system of the Ganga Plain. Values of pH and specific electrical conductivity of the river water of the study area decrease
whereas those of the urban drain water increase in post-monsoon period. The monsoon rain reduces the contents of Co, C-org,
Cr, Fe and Ni and enhances the contents of Cd, Sn and Zn in sediments of post-monsoon period. In soils, it reduces the contents
of Al, Co, Fe, Mn and Ni and enhances the contents of Cd, Sn and Zn in the post-monsoon period. These changes in concentrations
vary from metal to metal and from one geochemical domain to the other. An increase in the concentrations of few metals in
the soils from pre- to post-monsoon periods indicates that these metals were mobilized from the overflooding of metal rich
waste-water onto the fields during high water stage and also by reworking of the soils through sheet floods during the monsoon
time. Despite the changes in concentrations, metal dispersion patterns in each domain remain similar both in pre- and post-monsoon
periods which indicate that the geochemical and sediment-geomorphic processes operating for the metal dispersion and mobilization
in sediments are persistent even after large scale sediment-water movement and reworking of the sediments during the monsoon
period.
Received: 4 May 1998 · Accepted: 20 October 1998 相似文献
5.
为探讨渤海西部在多重环境因素变化下沉积物中重金属的环境地球化学行为,分析了渤海西部44个站位表层沉积物样品中8种重金属元素含量,研究了重金属元素的分布特征、环境影响因素及其生态风险。结果表明,渤海西部表层沉积物中As、Cu、Cd、Cr、Hg、Ni、Pb、Zn的平均含量分别为117 mg/kg、255 mg/kg、014 mg/kg、689 mg/kg、0037 mg/kg、303 mg/kg、223 mg/kg、757 mg/kg;Cu、Cr、Ni、Zn含量与有机碳含量、小于63 μm细粒沉积物呈显著正相关,其在表层沉积物中的分布明显受到有机质含量和沉积物粒径的控制,而As、Hg分布没有明显受到有机质含量的影响。富集系数显示,Cr、Ni、Pb和Zn为无富集,Cu、As为轻度富集,Cd和Hg为中度富集。与多种背景值和一致性沉积物质量基准相比较,渤海西部表层沉积物Pb、Cd的含量超出背景值,而Cu、Zn、Ni、Cr、As、Hg含量也存在一定的异常,但其含量水平引发有害生物效应的可能性不大,尽管重金属元素含量偏高,但生态风险较小。 相似文献
6.
Assessment of heavy metal pollution in surface water 总被引:4,自引:3,他引:1
D. Kar M.Sc. P. Sur M.Sc. S. K. Mandai M.Sc. T. Saha M.Sc. R. K. Kole M.Sc. 《International Journal of Environmental Science and Technology》2008,5(1):119-124
A total of 96 surface water samples collected from river Ganga in West Bengal during 2004–05 was analyzed for pH, EC, Fe, Mn, Zn, Cu, Cd, Cr, Pb and Ni. The pH was found in the alkaline range (7.21–8.32), while conductance was obtained in the range of 0.225–0.615 mmhos/cm. Fe, Mn, Zn, Ni, Cr and Pb were detected in more than 92% of the samples in the range of 0.025–5.49, 0.025–2.72, 0.012–0.370, 0.012–0.375, 0.001–0.044 and 0.001–0.250 mg/L, respectively, whereas Cd and Cu were detected only in 20 and 36 samples (0.001–0.003 and 0.003–0.032 mg/L). Overall seasonal variation was significant for Fe, Mn, Cd and Cr. The maximum mean concentration of Fe (1.520 mg/L) was observed in summer, Mn (0.423 mg/L) in monsoon but Cd (0.003 mg/L) and Cr (0.020 mg/L) exhibited their maximum during the winter season. Fe, Mn and Cd concentration also varied with the change of sampling locations. The highest mean concentrations (mg/L) of Fe (1.485), Zn (0.085) and Cu (0.006) were observed at Palta, those for Mn (0.420) and Ni (0.054) at Berhampore, whereas the maximum of Pb (0.024 mg/L) and Cr (0.018 mg/L) was obtained at the downstream station, Uluberia. All in all, the dominance of various heavy metals in the surface water of the river Ganga followed the sequence: Fe > Mn > Ni > Cr > Pb > Zn > Cu > Cd. A significant positive correlation was exhibited for conductivity with Cd and Cr of water but Mn exhibited a negative correlation with conductivity. 相似文献
7.
Heavy metal distribution and environmental status of Doon Valley soils, Outer Himalaya, India 总被引:1,自引:0,他引:1
K. K. Purohit P. K. Mukherjee P. P. Khanna N. K. Saini M. S. Rathi 《Environmental Geology》2001,40(6):716-724
Doon Valley is surrounded by two major river systems (Ganga and Yamuna) on either side, with a water divide passing nearly
across the centre of the valley, and is sandwiched between two mountain ranges in the fragile ecological systems of the Himalayan
foothills. In total 398 soil samples were collected from the valley in a grid pattern (∼1 sample per 2 km2) and investigated for their heavy metal (Cr, Cu, Ni, Pb and Zn) abundances that are environmentally sensitive. Comparison
of the heavy metal abundances with the contamination threshold values (CTV) revealed that most of these elemental abundances
in Doon Valley soils fall well within the range of the uncontaminated to slightly contaminated category. In the case of Cr
and Ni, a sizeable number of samples exceeded the CTV (250 and 100 mg kg–1 respectively) with an overall background value of 109 and 52 mg kg–1 respectively. Sites of high Cr and Ni mostly occur in the Ganga Catchment (GC) sector that includes even relatively undisturbed
forestland. The source of this contamination is attributed to geological factors which indicate contribution from the mafic
volcanics of the Lesser Himalaya. This is also consistent with the distribution pattern of Mn and Fe, though their abundance
levels are not alarming. The background concentration of Pb is low (22 mg kg–1) in Doon Valley soils; however, signs of gradual Pb contamination are palpable in and around the centre of the Dehra Dun
city and along the highways. Aluminium normalized heavy metal ratios were found to exhibit narrow variability in the case
of Cu, Ni and Cr and had good correlation with Al, indicating their affinity and association with the clay minerals. On the
other hand, Pb and Zn seem to be associated with non-silicate sources.
Received: 7 January 2000 · Accepted: 30 July 2000 相似文献
8.
This study reports on trace metal uptake by the grass species Melinis repens, growing in roadside soils and sediments in tropical northeastern Australia. Median total Cu, Pb, Ni and Zn concentrations
were significantly (P < 0.05) higher in road edge soils (Cu = 61.1 mg/kg, Pb = 97.3 mg/kg, Ni = 28.6 mg/kg, Zn = 729 mg/kg) than in background
soils collected away from roads (Cu = 5.8 mg/kg, Pb = 11.2 mg/kg, Ni = 3.7 mg/kg, Zn = 21 mg/kg). Significantly (P < 0.05) elevated Zn values were recorded in the stems of the M. repens specimens growing on roadside soils (231.6 mg/kg dry weight of tissue) compared with those of grasses growing on background
soils (40.8 mg/kg dry weight of tissue). Moreover, median Cu, Ni and Zn values in the roots of roadside grasses (Cu = 29.1 mg/kg,
Ni = 2.73 mg/kg, Zn = 169 mg/kg) were significantly (P < 0.05) higher than their respective levels in the roots of background M. repens samples (Cu = 5.98 mg/kg, Ni = 0.70 mg/kg, Zn = 22 mg/kg). A greenhouse experiment showed that Cu and Zn in road sediments
are labile and are available for uptake by M. repens. The studied roadside soils and sediments were leached with a diethylenetriaminepentaacetic acid–CaCl2–triethanolamine–HCl extraction solution, which proved to be a rudimentary indicator of Zn availability and uptake to the
root tissue of M. repens. The results demonstrate that trace metals in roadside grasses have the potential to be directed up the food-chain as grasses
are consumed by herbivores. In addition, bioavailable metal contaminants hosted by road sediments have the capacity to impact
on ecosystems downstream of roads because these sediments are mobilised by road runoff waters from road surfaces into adjoining
catchments. 相似文献
9.
Heavy metals in freshly deposited sediments of the Gomati River (a tributary of the Ganga River): effects of human activities 总被引:10,自引:0,他引:10
The concentrations of various metals (Cr, Cu, Co, Fe, Mn, Ni, Pb, Zn, and Cd) were determined in recently deposited surface
sediments of the Gomati River in the Lucknow urban area. Markedly elevated concentrations (milligrams per kilogram) of some
of the metals, Cd (0.26–3.62), Cu (33–147), Ni (45–86), Pb (25–77), and Zn (90–389) were observed. Profiles of these metals
across the Lucknow urban stretch show a progressive downstream increase due to additions from 4 major drainage networks discharging
the urban effluents into the river. The degree of metal contamination is compared with the local background and global standards.
The geoaccumulation index order for the river sediments is Cd>Zn>Cu>Cr>Pb. Significant correlations were observed between
Cr and Zn, Cr and Cu, Cu and Zn and total sediment carbon with Cr and Zn. This study reveals that the urbanization process
is associated with higher concentrations of heavy metals such as Cd, Cu, Cr, Pb, and Zn in the Gomati River sediments. To
keep the river clean for the future, it is strongly recommended that urban effluents should not be overlooked before their
discharge into the river.
Received: 16 February 1996 · Accepted: 29 February 1996 相似文献
10.
Heavy metals content and distribution in the surface sediments of the Guangzhou section of the Pearl River,Southern China 总被引:2,自引:2,他引:0
The long-term industrialization and urbanization of Guangzhou city may lead to heavy metal contamination of its aquatic sediment.
Nevertheless, only few studies have been published on the distribution and contamination assessment of heavy metals in this
urban river sediment. Thus, the major objective of this study was to quantitatively assess contamination of heavy metals and
their chemical partitioning in the sediments of the Guangzhou section of the Pearl River (GSPR). Surface sediment samples
were collected at 10 sites in the main river and 12 sites in the creeks of the GSPR. The total content of Cd was determined
by graphite furnace atomic adsorption spectrometry (GF-AAS), and content of Cr, Cu, Pb and Zn was determined by inductively
coupled plasma atomic emission spectrometry (ICP-AES). The chemical partitioning of these heavy metals in the sediments of
the main river was determined by the sequential selective extraction (SSE) method. Results indicated that the average total
concentrations of Cd, Cr, Pb, Cu and Zn in the sediments of the main river were 1.44, 63.7, 95.5, 253.6 and 370.0 mg/kg, respectively,
whereas they were 2.10, 125.5, 110.1, 433.7 and 401.9 mg/kg in the sediments of the creeks. The sediment at M4 and C9 sites
was heavily contaminated with about 8 and 11 of toxic unit, respectively. Cr, Cu, Pb and Zn were mostly bound to organic matter
and in the residual phase, whereas Cd was mostly associated with the soluble and exchangeable phase and the residual phase.
The mobility and bioavailability of Cd, Zn and Cr in the sediments of the main river were relatively higher than Cu and Pb,
due to higher levels in the soluble and exchangeable fraction and the carbonate fraction. The potential acute toxicity in
the sediments of the main river and creeks was mainly caused by Cu contamination, accounting for 21.7–37.1% and 16.9–46.3%
of the total toxicity, respectively, followed by Zn and Pb. Adverse biological effects induced by heavy metals would be expected
in the sediments of the GSPR. Therefore, the sediments of the GSPR, especially at M4 and C9 sites, need to be remediated to
maintain aquatic ecosystem health. 相似文献
11.
包头市典型工业区表层土壤中重金属污染状况及其潜在生态风险研究 总被引:3,自引:3,他引:0
为了解包头市典型工业企业对其所在地土壤中重金属含量的影响及污染现状,利用相关性系数对其表层土壤中7种重金属(Cu、Zn、Pb、Cr、Cd、Mn、Ni)来源进行研究,并采用内梅罗综合污染指数法和潜在生态危害指数对其污染状况进行评价。结果表明,7种重金属含量平均值均高于内蒙古土壤背景值,其中Cd、Mn、Ni超标率已达100%,而Cu、Pb、Zn的超标率分别为97%、93%和93%,只有Cr超标率较低(53%),污染程度依次为CdPbCuNiZnMnCr,其中Pb和Cd为重度污染,Cu、Zn、Ni为中度污染,Cr、Mn为轻度污染;Cu、Zn、Cr、Mn、Ni可能同时来自工业生产和交通运输两个源,而Pb和Cd除上述来源外,燃煤烟气的排放有较大贡献。潜在生态危害依次为CdPbCuNiCrZnMn,其中Cd的潜在生态风险最大,应予以高度重视,其他金属的风险均为轻微。 相似文献
12.
Eleven surface soil samples from calcareous soils of industrial areas in Hamadan Province, western Iran were analyzed for
total concentrations of Zn, Cd, Ni, Cu and Pb and were sequentially extracted into six fractions to determine the bioavailability
of various heavy metal forms. Total Zn, Cd, Ni, Cu and Pb concentrations of the contaminated soils were 658 (57–5,803), 125.8
(1.18–1,361), 45.6 (30.7–64.4), 29.7 (11.7–83.5) and 2,419 (66–24,850) mg kg−1, respectively. The soils were polluted with Zn, Pb, and Cu to some extent and heavily polluted with Cd. Nickel values were
not above regulatory limits. Copper existed in soil mainly in residual (RES) and organic (OM) fractions (about 42 and 33%,
respectively), whereas Zn occurred essentially as RES fraction (about 69%). The considerable presence of Cd (30.8%) and Pb
(39%) in the CARB fraction suggests these elements have high potential biavailability and leachability in soils from contaminated
soils. The mobile and bioavailable (EXCH and CARB) fractions of Zn, Cd, Ni, Cu, and Pb in contaminated soils averaged (7.3,
40.4, 16, 12.9 and 40.8%), respectively, which suggests that the mobility and bioavailability of the five metals probably
decline in the following order: Cd = Pb > Ni > Cu > Zn. 相似文献
13.
固体聚合膜电解浓集法是浓缩氚含量较低(1 Bq/m~3)的天然水样的常用方法,但因水样自身含有杂质离子或电解装置聚合膜带入杂质进入浓集液,使浓集液偏酸性,在测量过程中易产生化学淬灭效应,导致氚的测量值偏低。本文研究了水样自身存在的杂质离子和聚合膜上残留的杂质离子、样品溶液的pH值及其电导率所产生的化学淬灭效应的影响,实验表明,为减少化学淬灭效应,提高测量低含量氚的准确性,需保证水样溶液呈中性,电导率≤1μS/cm,同时避免杂质沉积在聚合膜上。如果水样溶液的pH值偏酸性、电导率大于1μS/cm,可采用酸碱混合型离子交换树脂去除水样中自身的杂质;对于聚合膜引入的杂质,可在电解后的水样中加入微量氨水将其pH值调节至中性。 相似文献
14.
Distribution of the trace elements Cr, Cu, Ni, Pb and Zn in surficial sediments of the river/sea environment in Danang –
Hoian area (Vietnam) was investigated to examine the degree of metal pollution caused by anthropogenic activities. Point sources
from domestic and industrial wastes are identified as dominant contributors of trace element accumulation. Surficial sediments
of Hoian River show extremely high total concentrations of Cu (Average Concentration 295 μg/g), Ni (AC 112 μg/g), Pb (AC 396 μg/g)
and Zn (AC 429 μg/g) that exceed assigned safety levels ER-M. Similarly, the sediments of Han River show high Pb (AC 188 μg/g)
and Zn (AC 282 μg/g) contents. In marine sediments of Thanhbinh beach Pb is also enriched (138 μg/g) above guideline levels.
In contrast the sediments of the Cude River are dominated by trace element concentrations close to background values.
Received: 17 December 1998 · Accepted: 6 May 1999 相似文献
15.
三峡库区澎溪河消落带土壤中重金属形态分布与迁移特征研究 总被引:2,自引:0,他引:2
消落带是水域与陆地的过渡地带,对水环境有着至关重要的影响。本文以三峡库区消落带面积最大的澎溪河流域作为研究区域,采集消落带土壤及其沿岸土壤样品,分析重金属形态分布特征,并使用地质累积指数法和风险评价准则(RAC)对重金属污染程度及生态风险进行评价。研究表明,消落带土壤中Pb、Cu、Cr、Cd、Zn和Ni平均含量分别为68.70、36.96、55.10、0.68、108.26、31.68 mg/kg,污染程度依次为CdPbZnCuNiCr,以Cd和Pb污染较为突出,普遍高于长江干流土壤,远高于重庆地区土壤。Cd的RAC值为20.62%,呈中等环境风险;其形态稳定性最差,以可还原态和酸提取态为主。Pb、Cu、Cr、Zn、Ni的RAC值为5.45%~10.0%,环境风险较低;且均以残渣态为主,占总量的54.69%~83.05%。以消落带沿岸土壤为对照,消落带形成后土壤中各重金属总量均有不同程度升高,且不同重金属在其增量部分的形态存在差异,Cr和Ni的增量部分以残渣态为主,Cd、Pb、Zn的增量以非残渣态为主。研究发现,由于受到水域与陆地污染源的双重影响,澎溪河流域重金属具有由沿岸向消落带沉积富集的趋势。 相似文献
16.
To evaluate muck sediments as a potential soil amendment, total and Mehlich III-extractable concentrations of Cd, Cu, Cr, Ni, Pb, Zn, and Co in 59 muck sediment samples from the St. Lucie Estuary were analyzed. A seven-step chemical fractionation procedure was used to assess the potential mobility of heavy metals. Except for Cd, the average total concentrations of the metals are lower than the reported average concentrations of these elements in municipal composts in the U.S.A. The concentrations were also below critical levels for the safe use of wastes and byproducts in agriculture, as established by the United States Environmental Protection Agency. The Cd, Cu, Cr, Ni, Pb, Zn and Co in the sediments were predominantly associated with silicate minerals in the residual form. Most metals in the muck sediments occur predominantly in weakly mobile or nonbioavailable forms. Use of mucks in neutral pH upland soils should not pose any significant hazards or risk to the environment. However, Cd, Cu, Cr, Ni, Pb, Zn, and Co, especially Zn, Cu, and Pb, could be more readily released from the muck sediments under acidic soil conditions. 相似文献
17.
Heavy metals in sediments of a large, turbid tropical lake affected by anthropogenic discharges 总被引:2,自引:0,他引:2
Bottom-water data and trace metal concentration of Cu, Cr, Ni, Pb, Co, Zn, and organic matter in surficial sediment samples
from 13 sampling stations of Lake Chapala in Mexico were studied. The lake is turbid with a great amount of flocculated sediments
as a result of wind mixing, sediment re-suspension, and Lerma River discharges. Al distribution pattern in sediments was used
as an indicator of the Lerma River discharges into Lake Chapala. The highest values of Cu (33.27 ppm), Cr (81.94 ppm), Pb
(99.8 ppm), and Zn (149.7 ppm) were detected in sediments near the lake outlet. The bioavailable metal fraction is low for
all metals except Pb, which shows 65–93% of the total metal concentration in bioavailable form. The minimum energy zone in
the lake was related to organic matter concentration and was located in the SE part of the lake. An analysis of the studied
parameters shows two zones: eastern zone (fluvio-deltaic) and central-western zone (lacustrine).
Received: 9 September 1998 · Accepted: 16 November 1998 相似文献
18.
This work is part of a research study which is intended to study the degree of anthropogenic influences of the trace metal
distribution of soils from Danang-Hoian area (Vietnam). Cu, Ni, Zn and Zr show significant effects in most of the cultivated
soil categories, especially in the industrial soils. Extremely high levels of Pb (up to 742 μg/g) are observed in the industrial
soil category, which shows an enrichment factor 114 as compared to rural soils. Cd shows only a relative local enrichment
with the maximum level of 4.6 μg/g in urban soils. Sequential extraction was performed in selected samples to evaluate the
geochemical trace metals. The result indicates that Zn and Cr are mainly found in the crystal and amorphous Fe oxide bounded
forms. The contents of Cr in these fractions comprise more than 94% of total extractable Cr. In the case of Zn, 85% of total
extractable Zn is in fractions FV and FVI. Cu is mainly found in the organic fraction at an average of 39.3% of total extractable content. On the other hand, heavy
metal contents show an increasing tendency in the fine fraction (silt and clay).
Received: 4 February 1998 · Accepted: 26 November 1998 相似文献
19.
Trace elements contamination of agricultural soils affected by sulphide exploitation (Iberian Pyrite Belt,Sw Spain) 总被引:1,自引:0,他引:1
Agricultural soils of the Riotinto mining area (Iberian Pyrite Belt) have been studied to assess the degree of pollution by
trace elements as a consequence of the extraction and treatment of sulphides. Fifteen soil samples were collected and analysed
by ICP-OES and INAA for 51 elements. Chemical analyses showed an As–Cu–Pb–Zn association related with the mineralisation of
the Iberian Pyrite Belt. Concentrations were 19–994 mg kg−1 for As, 41–4,890 mg kg−1 for Pb, 95–897 mg kg−1 for Zn and of 27–1,160 mg kg−1 for Cu. Most of the samples displayed concentrations of these elements higher than the 90th percentile of the corresponding
geological dominium, which suggests an anthropogenic input besides the bedrock influence. Samples collected from sediments
were more contaminated than leptosols because they were polluted by leachates or by mining spills coming from the waste rock
piles. The weathering of the bedrock is responsible for high concentrations in Co, Cr and Ni, but an anthropogenic input,
such as wind-blown dust, seems to be indicative of the high content of As, Cu, Pb and Zn in leptosols. The metal partitioning
patterns show that most trace elements are associated with Fe amorphous oxy-hydroxides, or take part of the residual fraction.
According to the results obtained, the following mobility sequence is proposed for major and minor elements: Mn, Pb, Cd, > Zn,
Cu > Ni > As > Fe > Cr. The high mobility of Pb, Cu and Zn involve an environmental risk in this area, even in soils where
the concentrations are not so high. 相似文献
20.
Metal contamination of the environment by placer and primary gold mining in the Adola region of southern Ethiopia 总被引:3,自引:0,他引:3
Primary and placer gold mining sites in southern Ethiopia were studied to see the contribution of mining to the accumulation of metals in different environmental media. Sediment, water and plant samples were analyzed for Al, Mn, Fe, As, Ni, Cr, Cu, Co, Pb, W, Sb, Mo, Zn and V. Water parameters (pH, Eh, TDS, anions and cations) were also measured. The sediment analyses results show that the most abundant metals are Ni (average 224.7 mg/kg), Cr (199 mg/kg), Cu (174.2 mg/kg), V (167.3 mg/kg), Zn (105.5 mg/kg), Pb (61.5 mg/kg) and As (59.7 mg/kg) in the primary gold mining sites while the placer sites show high concentration of V (average 301.2 mg/kg), Cr (260.4 mg/kg), Zn (179 mg/kg), Ni (113.4 mg/kg), Cu (46.7 mg/kg), As (32.2 mg/kg) and Co (31 mg/kg). The metals Cu, Ni, W, Cr, As and Pb in primary and Sb, W, Cr, Ni, Zn, As and Mo in placer gold mining sites have geoaccumulation indexes (I
geo) from one to four indicating considerable accumulation of these metals. Waters from both primary and placer mining sites are near neutral to alkaline. Arsenic (average 92.8 μg/l), Ni (276.6 μg/l), Pb (18.7 μg/l), Sb (10.7 μg/l), Mn (1 mg/l), Fe (8.3 mg/l) and Al (23.8 mg/l) exceeded the guideline value for drinking water. Plants show high concentration of Cr (average 174.5 mg/kg), Ni (163.5 mg/kg), Zn (96 mg/kg) and W (48 mg/kg). Zinc, W, Mo, Ni and Cr show the maximum biological absorption coefficient (BAC) ranging 0.4–1.7, 0.1–104.6, 1.1–2.6, 0.2–1.6 and 0.2–3.6, respectively, and the results suggest bioaccumulation of these elements in plants. The minerals especially sulfides in the ore aggregate are the ultimate source of the metals. The release of the metals into the environmental media is facilitated (in addition to normal geologic processes) by human activities related to gold mining. 相似文献