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1.
S. Chakraborty G. Owens 《International Journal of Environmental Science and Technology》2014,11(5):1259-1270
Algal species which are ubiquitous along the coastlines of many countries reflect the environmental conditions of the coastal seawater and may serve as useful biomonitors of anthropogenic pollution. Heavy metal concentrations of ten elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of potential environmental concern were determined in seawater, sediments and twelve species of benthic marine macroalgae from four locations (Glenelg, Port Adelaide, Port Broughton and Port Pirie) along the South Australian coastline. The four sites chosen represented varying degrees of metal contamination, where the capacity for benthic macroalgae to accumulate heavy metals from the environment was evaluated. Spatial differences in heavy metal concentration in both seawaters and sediments were observed at all sites with the highest concentrations of heavy metals including Cd (125 μg g?1), Pb (2,425 μg g?1) and Zn (7,974 μg g?1) found in the finer sediment fractions (<250 μm) of Port Pirie. While all algal species studied (Acrosorium polyneurum, Anotrichium tenue, Cystophora Cephalornithos Cystophora monillifera, Cystophora monilliformis, Dictyopteris australis, Gelidium micropterum, Gracilaria, Hormophysa Cuneiformis, Sargassum cinctum, Scaberia agardhii and Ulva lactuca) accumulated metals to varying degrees, Blindigia marginata was a good biomonitor species for a number of metals including Cd, Co, Cr, Fe, Pb and Zn, exhibiting both relatively high total metal concentrations and significant concentration factors. 相似文献
2.
Accumulation of heavy metals in wild commercial fish from the Baotou Urban Section of the Yellow River,China 总被引:1,自引:0,他引:1
In this work we studied the accumulation of heavy metals in nine species of fish with different life and feeding habitats
which are native and major commercial fish in the Baotou Urban Section of the Yellow River. The results showed that the concentration
of heavy metals was significantly dependent on fish species; the pollution index of heavy metals in different species were
ranked as Hemiculter leucisclus > Carassius auratus auratus > Hemibarbus maculatus > Megalobrama amblycephala > Abbottina rivularis > Cyprinus carpio > Squaliobarbus curriculus > Perccottus glehni > Saurogobio dabryi. Product–moment correlation coefficients among the metal pairs Pb–Zn, Cu–Cd, Cu–Zn, Cu–Pb, Pb–Cd, and Zn–Cd revealed there
was no competitions between metals in each tissue. Correlations between heavy metal concentrations and fish length or weight
indicated that accumulation of the heavy metals by the different fish species was related to their surrounding environments
and their life and feeding habitats. According to the mean bioconcentration factors (BCFs), the heavy metal concentrations
in these nine species were ranked Zn ≫ Cu > Cd ≈ Pb. In this work, the bioaccumulation factors (BAFs) were developed by using
the sum of exchangeable and bound-to-carbonate heavy metals as Cs values. It was found that BAFs better reveal the accumulation
characteristics of the heavy metals in the fish, which might provide an effective method for assessing bioaccumulation of
heavy metals. 相似文献
3.
A DADOLAHI-SOHRAB M GARAVAND-KARIMI H RIAHI H PASHAZANOOSI 《Journal of Earth System Science》2012,121(1):241-250
This study was carried out to evaluate the seasonal variations of seaweed biomass and species composition at six different
sites along the coastal areas in Bushehr Province. Sampling depths varied among sites, from 0.3 to 2.0 m below mean sea level.
A total of 37 (i.e., 10 Chlorophyta, 12 Phaeophyta and 15 Rhodophyta) seaweed species were collected. Studies were conducted
for quantifying the seaweeds during four seasons from October 2008 until July 2009. During present research, Ulva intestinalis and Cladophora nitellopsis of green, Polycladia myrica, Sirophysalia trinodis and Sargassum angustifolium of brown and Gracilaria canaliculata and Hypnea cervicornis of red seaweeds showed highest biomass in coastal areas of Bushehr Province. The Cheney‘s ratio of 2.1 indicated a temperate
algal flora to this area. All sites exhibited more than 50% similarity of algal species, indicating a relatively homogenous
algal distribution. Total biomass showed the highest value of 3280.7 ± 537.8 g dry wt m − 2 during summer and lowest value of 856.9 ± 92.0 g dry wt m − 2 during winter. During this study, the highest and lowest seaweed biomass were recorded on the site 2 (2473.7 ± 311.0 g dry
wt m − 2) and site 5 (856.7 ± 96.8 g dry wt m − 2), respectively. 相似文献
4.
Heavy metals and rare earth elements (REEs) in soil from the Nam Co Basin,Tibetan Plateau 总被引:1,自引:0,他引:1
Chaoliu Li Shichang Kang Xiaoping Wang F. Ajmone-Marsan Qianggong Zhang 《Environmental Geology》2008,53(7):1433-1440
Twenty-eight soil samples collected from the Nam Co Basin, Tibetan Plateau, have been analyzed for heavy metals (Cd, Cr, Ni,
Cu, Zn, Pb and Mn), arsenic (As) and rare earth elements (REEs). In addition, for establishing the basic physio-chemical characteristics
of the soil, pH, total organic concentration, electrical conductivity, and effective cation exchange capacity were measured.
The results indicate that soil in the Nam Co Basin is still at an early alkaline weathering stage (pH = 7.94). Mean concentrations
of heavy metals and As decreased as follows: Mn > Cr > Zn > Pb > Ni > Cu > As > Cd. The values of Cd, Cr, As, Pb and REEs
in soil from the Nam Co Basin are higher relative to averaged background values over China. The chondrite-normalized diagrams
of REEs suggest high REE(ΣLa → Eu)—enrichment, HREE(ΣGd → Lu)—depletion and Eu—depletion. Vertical profiles indicate that
both heavy metals (except As) and REEs primarily exist in the surface soil. However, heavy metals and REEs vary in the surface
soil between the southern and the northern bank of Nam Co. These differences are controlled mainly by parent materials. 相似文献
5.
Contamination and potential mobility assessment of heavy metals in urban soils of Hangzhou,China: relationship with different land uses 总被引:1,自引:0,他引:1
Concentration and distribution of heavy metals (Cd, Cu, Pb and Zn) in urban soils of Hangzhou, China, were measured based
on different land uses. The contamination degree of heavy metals was assessed on the basis of pollution index (PI), integrated
pollution index (IPI) and geoaccumulation index (I
geo). The 0.1 mol l−1 HCl extraction procedure and gastric juice simulation test (GJST) were used to evaluate the potential mobility and environmental
risk of heavy metals in urban soils. The average concentration of Cd, Cu, Pb and Zn in urban soils was measured at 1.2 (with
a range of 0.7–4.6), 52.0 (7.4–177.3), 88.2 (15.0–492.1) and 206.9 (19.3–1,249.2) mg kg−1, respectively. The degree of contamination increased in the order of industrial area (IA) > roadside (RS) > residential and
commercial areas (RC) > public park and green areas (PG). The PIs for heavy metals indicated that there is a considerable
Cd, Cu, Pb and Zn pollution, which originate from traffic and industrial activities. The IPI of these four metals ranged from
1.6 to 11.8 with a mean of 3.5, with the highest IPI in the industrial area. The assessment results of I
geo also supported that urban soil were moderately contaminated with Cd and to a lesser extent also with Cu, Pb and Zn. The IP
and I
geo values reveal the pollution degree of heavy metal was the order of Cd > Pb > Zn ≈ Cu. It was shown that mobility and bioavailability
of the heavy metals in urban soils increased in the order of Cd > Cu > Zn ≈ Pb. Owing to high mobility of Cd and Cu in the
urban soils, further investigations are needed to understand their effect on the urban environment and human health. It is
concluded that industrial activities and emissions from vehicles may be the major source of heavy metals in urban contamination.
Results of this study present a rough guide about the distribution and potential environmental and health risk of heavy metals
in the urban soils. 相似文献
6.
Simultaneous competitive adsorption behavior of Cd, Cu, Pb and Zn onto nine soils with a wide physical–chemical characteristics
from Eastern China was measured in batch experiments to assess the mobility and retention of these metals in soils. In the
competitive adsorption system, adsorption isotherms for these metals on the soils exhibited significant differences in shape
and in the amount adsorbed. As the applied concentration increased, Cu and Pb adsorption increased, while Cd and Zn adsorption
decreased. Competition among heavy metals is very strong in acid soils with lower capacity to adsorb metal cations. Distribution
coefficients (K
dmedium) for each metal and soil were calculated. The highest K
dmedium value was found for Pb and followed by Cu. However, low K
dmedium values were shown for Zn and Cd. On the basis of the K
dmedium values, the selectivity sequence of the metal adsorption is Pb > Cu > Zn > Cd and Pb > Cu > Cd > Zn. The adsorption sequence
of nine soils was deduced from the joint distribution coefficients (K
dΣmedium). This indicated that acid soils with low pH value had lower adsorption capacity for heavy metals, resulting in much higher
risk of heavy metal pollution. The sum of adsorbed heavy metals on the soils could well described using the Langmuir equation.
The maximum adsorption capacity (Q
m) of soils ranged from 32.57 to 90.09 mmol kg−1. Highly significant positive correlations were found between the K
dΣmedium and Q
m of the metals and pH value and cation exchange capacity (CEC) of soil, suggesting that soil pH and CEC were key factors controlling
the solubility and mobility of the metals in soils. 相似文献
7.
Distribution and enrichment of trace metals in marine sediments of Bay of Bengal,off Ennore,south-east coast of India 总被引:1,自引:0,他引:1
In order to avoid the pollution of trace metals in marine environment, it is necessary to establish the data and understand
the mechanisms influencing the distribution of trace metals in marine environment. The concentration of heavy metals (Fe,
Mn, Cr, Cu, Ni, Pb, Zn, Co and Cd) were studied in sediments of Ennore shelf, to understand the metal contamination due to
heavily industrialized area of Ennore, south-east coast of India. Concentration of metals shows significant variability and
range from 1.7 to 3.7% for Fe, 284–460 μg g−1 for Mn, 148.6–243.2 μg g−1 for Cr, 385–657 μg g−1 for Cu, 19.8–53.4 μg g−1 for Ni, 5.8–11.8 μg g−1 for Co, 24.9–40 μg g−1 for Pb, 71.3–201 μg g−1 for Zn and 4.6–7.5 μg g−1 for Cd. For various metals the contamination factor (CF) and geoaccumulation index (I
geo) has been calculated to assess the degree of pollution in sediments. The geoaccumulation index shows that Cd, Cr and Cu moderately
to extremely pollute the sediments. This study shows that the major sources of metal contamination in the Ennore shelf are
land-based anthropogenic ones, such as discharge of industrial wastewater, municipal sewage and run-off through the Ennore
estuary. The intermetallic relationship revealed the identical behavior of metals during its transport in the marine environment. 相似文献
8.
Distribution and speciation of heavy metals and their sources in Kumho River sediment,Korea 总被引:1,自引:1,他引:0
The interaction between heavy metals and river sediment is very important because river sediment is the sink for heavy metals
introduced into a river and it can be a potential source of pollutants when environmental conditions change. The Kumho River,
the main tributaries of the Nakdong River in Korea, can be one of the interesting research targets in this respect, because
it runs through different geologic terrains with different land use characteristics in spite of its short length. Various
approaches were used, including mineralogical, geochemical, and statistical analyses to investigate the distribution and behavior
of heavy metals in the sediments and their sources. The effect of geological factor on the distribution of these metals was
also studied. No noticeable changes in the species or relative amounts of minerals were observed by quantitative X-ray diffraction
in the sediments at different stations along the river. Only illite showed a significant correlation with concentrations of
heavy metals in the sediments. Based on an average heavy metal concentration (the average concentrations of Cd, Co, Cr, Cu,
Ni, Pb, and Zn were 1.67, 20.9, 99.7, 125, 97.6, 149, 298 ppm, respectively), the sediments of the Kumho River were classified
as heavily polluted according to EPA guidelines. The concentrations of heavy metals in the sediments were as follows: Zn > Pb > Cu > Ni > Cr > Co > Cd.
In contrast, contamination levels based on the average I
geo (index of geoaccumulation) values were as follows: Pb > Cd > Zn > Cu > Co = Cr > Ni. The concentrations of heavy metals increased
downstream (with the exception of Cd and Pb) and were highest near the industrial area, indicating that industrial activity
is the main factor in increasing the concentrations of most heavy metals at downstream stations. Sequential extraction results,
which showed increased heavy metal fractions bound to Fe/Mn oxides at the downstream stations, confirmed anthropogenic pollution.
The toxicity of heavy metals such as Ni, Cu, and Zn, represented by the exchangeable fraction and the fraction bound to carbonate,
also increased at the downstream stations near the industrial complexes. Statistical analysis showed that Pb and Cd, the concentrations
of which were relatively high at upstream stations, were not correlated with other heavy metals, indicating other possible
sources such as mining activity. 相似文献
9.
Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory 总被引:1,自引:0,他引:1
The present study deals with the characterization of effluent released from sponge iron industries and distribution of heavy
metals in soil and macrophytes near to effluent discharge channel. Apart from this, accumulation of heavy metals in nearby
soil and vegetation system irrigated with effluent-contaminated water is also the subject of this study. Physico-chemical
analysis of effluent reveals that the concentration of total suspended solids (TSS), total hardness (TH), iron (Fe2+), and oil and grease are greater than the IS (1981) norms for discharge of water into inland water body. The soil along the sides of the effluent channel also shows higher
concentration of heavy metals than the background soil. The enrichment of the heavy metals are in the order of Chromium (Cr) > Iron
(Fe) > Manganese (Mn) > Zinc (Zn) > Copper (Cu) > Cadmium (Cd). Macrophytes growing along the sides of the effluent channel
also show significant accumulation of heavy metals almost in the same order as accumulated in soil. Higher uptake of heavy
metals by these varieties reveals that these species can be used for future phytoremediation. The effluent as well as contaminated
water is extensively used for irrigation for growing vegetables like tomato (Lycopersicon esculatum) in the surrounding areas. Heavy metal accumulation in this agricultural soil are in the sequence of Cr > Fe > Mn > Zn > Cu > Cd.
More or less similar type of accumulation pattern are also found in tomato plants except Fe and Zn exceeding Cr and Mn. Transfer
Factor of heavy metals from soil to tomato plants (TFS) shows average value of <1, suggesting less uptake of heavy metals from soil. Among the plant parts studied, fruit shows
least accumulation. Although tomato plants show some phenotypic changes, the survival of tomato plants as well as least accumulation
of metals in fruit reveals their tolerance to heavy metals. Therefore it may be suggested that this plant can be grown successfully
in the heavy metal contaminated soil. Further research work on in situ toxicity test will be necessary in order to identify
the most resistive variety on this particular type of contaminated site. 相似文献
10.
Distillery and tanneries are major source of heavy metals pollution in natural wetland sites in India. Present study deals
with the heavy metals accumulation potential of Typha angustifolia and Cyperus esculentus growing in distillery and tannery effluent polluted wetland sites. The metal accumulation pattern in both macrophytes showed
direct correlation with the metal content in sediments. Both macrophytes were observed root accumulator for Fe, Cr, Pb, Cu,
and Cd. The metal accumulation in T. angustifolia was found higher than C. esculentus, and accumulation pattern was Fe > Mn > Cr > Zn > Pb > Cu > Ni > Cd. Simultaneously, chlorophyll, protein, cysteine, and
ascorbic acid were also induced in T. angustifolia than C. esculentus. In addition, formation of multinucleolus in shoot of T. angustifolia was found an evidence of extra protein synthesis for tolerance under stress conditions. Hence, C. esculentus was observed potential but less tolerance for metals than T. angustifolia. Therefore, these wetland plants could be used for phytoremediation of heavy metals from wastewater. 相似文献
11.
Mobility and ecological risk assessment of heavy metals in surface sediments of Xiamen Bay and its adjacent areas,China 总被引:4,自引:1,他引:3
Xiamen Bay (XMB) has received substantial loadings of pollutants from industrial and municipal wastewater discharged since
the 1980s. To assess ecological risks and the current spatial changes of metal contaminants in bottom surface sediments, 12
samples were collected. Samples were subjected to a total digestion technique and analyzed by ICP–OES for Cu, Pb, Zn, Cr,
and Cd, and by AFS for Hg and As. Among these metals, Zn had the highest values (68–268 mg kg−1), followed by Pb (27–71 mg kg−1), and lower concentrations were found for Cd (42–1,913 μg kg−1) and Hg (0–442 μg kg−1). In comparison with the average crustal abundance values, the results indicated that nearly half of the sediment samples
of XMB and its adjacent areas were contaminated by Cd, Pb, Zn, and As. Furthermore, based on the modified BCR sequential extraction
procedure, the chemical speciation of heavy metals (Cd, Cr, Cu, Pb, Zn, Hg, and As) in selected sediment samples were evaluated
in this study. Data from BCR sequential extractions indicated that Cd posed a medium ecological risk, whereas, Cr posed low
risk since its exchangeable and carbonate fractions were below 4%, and the mobility of heavy metals in XMB decreased in the
order Cd > Pb > Cu > Zn > Hg > As > Cr. By applying mean effects range median quotients (mERMQ), the results showed that Yuandang
Lagoon with mERMQ value >0.5 would be expected to have the greatest potential toxic risk in amphipod within XMB and its adjacent
areas. 相似文献
12.
Competitive adsorption,release and speciation of heavy metals in the Yellow River sediments,China 总被引:2,自引:0,他引:2
Qingyun Fan Jiang He Hongxi Xue Changwei LÜ Ying Liang Saruli Ying Sun Lili Shen 《Environmental Geology》2007,53(2):239-251
The competitive adsorption and the release of selected heavy metals and their speciation distribution before and after adsorption
in the Yellow River sediments are discussed. The adsorption of metals onto sediments increases with increasing pH value and
decreases with increasing ionic strength. The competitive coefficient K
c and the distribution coefficient K
d are obtained to analyze the competitive abilities of selected heavy metals, which are ranked as Pb > Cu >> Zn > Cd. The competition
among selected heavy metals becomes more impetuous with increasing ion concentration in water. Speciation analysis was done
by an improved analytical procedure involving five steps of sequential extraction. Cu, Pb and Zn were mainly transformed into
the carbonate-bound form (50.8–87.7%) in adsorption. Most of (60.7–77.3%) Cd was transformed into the exchangeable form, and
the percentage of carbonate-bound Cd was 19.7–30.4%. The release reaction was so quick that the release capacity of selected
heavy metals from sediments to aqueous solution reached half of the maximum value only in 30 s. As opposed to adsorption,
the release capacities of selected heavy metals were ranked as Cd > Zn >> Cu > Pb. In this study, Cd produces the most severe
environmental hazards, because its concentration in the release solution is 85.8 times more than the human health criteria
of US EPA. 相似文献
13.
Experiments in which two species of freshwater green algae, Ankistrodesmus sp. and Selenastrum, were cultured in dilute solutions of metals chelated with EDTA reveal massive uptake of U and Ba, but relatively minor uptake of Ni, Co and V. For 2-ppm metal-spiked TBIM culture media at pH 8.1–8.2 and growth durations of 3–21 days at 13–16°C, both species accumulate U and Ba at levels of 1000 to 10,000 ppm by dry weight, representing a concentration factor of up to 5000 times the aqueous metal solute concentration. Uptake was comparable for passage of 100-ml spiked culture media through algal mats over 100 min. For aqueous solute concentrations of 20 ppb Ba, Co, Ni and U the algae adsorbed 3000–4000 ppm U and Ba giving concentration factors up to 200,000. With 40 ppb U, the algae adsorbed 6000 ppm, representing a concentration factor of 150,000. Co and Ni in the algae were present at levels below analytical sensitivity. The Ba aqueous concentration was about equivalent to, and the U concentration 100 times natural marine water abundances. For 2-ppm Co-, Ni- and V-spiked culture media, algal uptake was 40–600 ppm Ni, 17 ppm Co and 12 ppm V, respectively.Given the abundance of algae in both fresh and marine waters, coupled with the known association of plankton with U-rich Black Sea muds, the experimental results may indicate that algae also play a significant role in mediating U and Ba uptake from the hydrosphere. The recorded levels of algal uptake for metals are ~1000 × (U), ~100 × (Ba), ~100 × (Ni), ~20 × (Co), and ~6 × (V), previously reported abundances for “typical” marine plants. 相似文献
14.
R VENKATACHALAPATHY S VEERASINGAM N BASAVAIAH T RAMKUMAR K DEENADAYALAN 《Journal of Earth System Science》2011,120(5):885-895
In this study, environmental magnetic, heavy metal and statistical analyses were conducted on 21 surface sediments collected
from Chennai coast, India, to examine the feasibility of heavy metal pollution using magnetic susceptibility. The Chennai
coastal sediment samples are dominated by ferrimagnetic minerals corresponding to magnetite-like minerals. The percentage
of frequency dependent magnetic susceptibility reflects the presence of super-paramagnetic/single domain magnetic minerals
in Chennai harbour, Cooum and Adayar rivers sediments. High pollution load index in sample E1, E2, CH7, C11, C12 and A16 is
mainly due to anthropogenic activities such as, harbour activities, Cooum and Adayar rivers input and industrial effluent.
Factor analysis shows that the magnetic concentration dependent parameters (χ, χ
ARM and SIRM) covary with the heavy metal concentrations, suggesting that the input of magnetic minerals and heavy metals in
Chennai coastal sediments are derived from the same anthropogenic sources. Strong correlation obtained between pollution load
index (PLI) and concentration dependent parameters (χ, χ
ARM and SIRM) for the polluted samples with magnetic susceptibility excess of 50×10 − 8 m3kg − 1. Significant correlations between heavy metals and magnetic susceptibility point out the potential of magnetic screening/monitoring
for simple and rapid proxy indicator of heavy metal pollution in marine sediments. 相似文献
15.
National scale evaluation of groundwater chemistry in Korea coastal aquifers: evidences of seawater intrusion 总被引:3,自引:2,他引:1
Youngyun Park Jin-Yong Lee Jeong-Hee Kim Sung-Ho Song 《Environmental Earth Sciences》2012,66(3):707-718
Pollution of groundwater by seawater intrusion poses a threat to sustainable agriculture in the coastal areas of Korea. Therefore, seawater intrusion monitoring stations were installed in eastern, western, and southern coastal areas and have been operated since 1998. In this study, groundwater chemistry data obtained from the seawater intrusion monitoring stations during the period from 2007 to 2009 were analyzed and evaluated. Groundwater was classified into fresh (<1,500 μS/cm), brackish (1,500–3,000 μS/cm), and saline (>3,000 μS/cm) according to EC levels. Among groundwater samples (n = 233), 56, 7, and 37% were classified as the fresh, brackish, and saline, respectively. The major dissolved components of the brackish and saline groundwaters were enriched compared with those of the fresh groundwater. The enrichment of Na+ and Cl− was especially noticeable due to seawater intrusion. Thus, the brackish and saline groundwaters were classified as Ca–Cl and Na–Cl types, while the fresh groundwater was classified as Na–HCO3 and Ca–HCO3 types. The groundwater included in the Na–Cl types indicated the effects of seawater mixing. Ca2+, Mg2+, Na+, K+, SO4 2−, and Br− showed good correlations with Cl− of over r = 0.624. Of these components, the strong correlations of Mg2+, SO4 2−, and Br− with Cl− (r ≥ 0.823) indicated a distinct mixing between fresh groundwater and seawater. The Ca/Cl and HCO3/Cl ratios of the groundwaters gradually decreased and approached those of seawater. The Mg/Cl, Na/Cl, K/Cl, SO4/Cl, and Br/Cl ratios of the groundwaters gradually decreased, and were similar to or lower than those of seawater, indicating that Mg2+, Na+, K+, SO4 2−, and Br−, as well as Cl− in the saline groundwater can be enriched by seawater mixing, while Ca2+ and HCO3 − are mainly released by weathering processes. The influence of seawater intrusion was evaluated using threshold values of Cl− and Br−, which were estimated as 80.5 and 0.54 mg/L, respectively. According to these criteria, 41–50% of the groundwaters were affected by seawater mixing. 相似文献
16.
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
17.
Keli Zhao Weiwen Zhang Ling Zhou Xingmei Liu Jianming Xu Panming Huang 《Environmental Earth Sciences》2009,59(3):519-527
Many studies have been conducted on model transfer in soil–plant systems. However, relatively little information is available
on modeling metal transfer in soil–rice system and associated risk assessment in real paddy fields. Based on a random sampling
method from Nanxun, Shengzhou and Wenling in Zhejiang province, China, 15 pairs of rice and the corresponding soil samples
were respectively collected for analysis of heavy metals and soil pH. The results showed that the accumulation ability of
rice for different heavy metals was significantly different (p < 0.05), and was in the order of Cd > Zn > Cu > Ni > Cr > Pb. The relationships of heavy metals in rice with those in soil,
along with soil pH, were well described by linear regression models. Except for Pb, the contents of most metals in rice were
positively correlated with those of the soil. Soil pH was negatively correlated with the contents of Cd, Zn and Ni in rice,
and positively correlated with Pb in rice; however, it had less effect on Cr and Cu. Based on risk reference dose (RfD), the risk assessment data indicated that the rice grown in Zhejiang paddy fields does pose some potential Cd and Cr contamination
risk to food safety; rice in Shengzhou posed light Ni risk. 相似文献
18.
Surface soil and sediment samples were collected from the surroundings of the Ittehad Chemical Industries Kalashah Kaku industrial
zone to assess residual level of 19 organochlorine pesticides (OCPs) and identify their sources. DDTs and HCHs were most prevalent
OCPs and general pattern of contamination followed the order: ∑DDT > ∑HCH > dicofol > endrin > heptachlor > dieldrin > endosulfan
II. Total measured concentrations of HCHs (6.38–121.71 ng/g) and DDTs (759.65–1811.98 ng/g) were greater in the soil samples
collected from fodder/rice fields irrigated with the factory effluents and in the surrounding of waste disposal site. Ratios
of β to γ-HCH highlighted an old mixed source of technical HCH and lindane in surface soils. Predominance of p,p′-DDT and p,p′-DDE among isomers and metabolites showed that large quantity of technical grade DDT is still present in the surrounding
surface soils. Six soil samples were categorized as heavy polluted soils (class III category of DDT > 1,000 ng/g), two soil
samples into less polluted soil between class I and II (50–500 ng/g) and 28 soil samples as non-polluted (<50 ng/g) according
to environmental quality standards for surface soils. Six soil samples were categorized as less polluted between class I and
II of HCHs (50–500 ng/g). Greater concentration of DDTs and HCHs above quality guideline poses potential exposure risk to
biological organisms, safety of agricultural products and human health in the surrounding of the Ittehad Chemical Industries. 相似文献
19.
The purpose of this study was to determine the levels of heavy metals namely cadmium (Cd), copper (Cu) and lead (Pb) in the
five aquatic plants. For this purpose, the concentration of heavy metals were measured in water and in the five aquatic plant
species, Lepironia articulata, Pandanus helicopus, Scirpus grossus, Cabomba furcata and Nelumbo nucifera, in 15 sites from Tasik Chini. The concentrations were different among the plant species as well as among the parts of plants.
The highest concentration of heavy metals among the aquatic plants and plant parts was found in the roots of S. grossus. The concentrations of Cd in the leaves and stems of submerged aquatic plant, C. furcata, were higher than concentration of Cd in the leaves and stems of emergent aquatic plant and floating leaf plant. The concentration
of Cu in the stem of C. furcata was greater than that in the leaf, while the concentration of Cd was more in the leaf than in the stem. The heavy metal contents
of the aquatic plants were in descending order of Pb > Cu > Cd. The metal concentration quotient of leaves/roots and stems/roots
(ML/MR and MS/MR) were calculated. The highest internal translocation was found in P. helicopus, while the lowest internal translocation was found in S. grossus. 相似文献
20.
Although marine lagoons are ubiquitous features along coastal margins, studies investigating the dynamics of metal, organic
matter, and nutrient concentrations in such systems are rare. Here we present a comprehensive examination of the temporal
and spatial gradients in dissolved trace metals (Ag, Cd, Cu, Mn, Pb), organic and inorganic nutrients (POC, PON, DOC, N03
−, NH4
+, H4SiO4, PO4
−3, and urea), and algal biomass in a lagoon estuary, Great South Bay (GSB), New York, USA. While this estuary has experienced
a series of environmental problems during recent decades (urbanization, loss of fisheries, harmful algal blooms), root causes
are largely unknown, in part because levels of bioactive substances, such as trace metals, have never been measured. Sampling
was undertaken within multiple estuarine, riverine, and groundwater sites during spring, summer, and fall. Trace metal tracers
(e.g., Ag, Mn) and statistical analyses were used to differentiate the influences of natural and anthropogenic processes on
the chemical composition of the lagoon. Our analyses revealed three clusters of biogeochemical constituents that behaved similarly
in GSB: constituents under strong biological control such as POC, PON, DOC and chlorophyll,a; elements indicative of benthic remobilization processes such as Mn, Cd, and Cu; and constituents strongly influence by anthropogenic
processes such as Ag, Pb, PO4
−3, NO3
−, and NH4
+. Although GSB is surrounded by a densely populated watershed (c. 1 million people), it does not appear to be significantly
contaminated by trace metals compared to other urban estuaries. Levels of DOC (up to 760 μM) in GSB were well correlated with
phytoplankton biomass and exceeded at least 98% of values reported in similar mid Atlantic estuaries at the same salinities.
These high levels of DOC are likely to be an important source of carbon export to the coastal ocean and likely promote mixotrophic
harmful algal blooms in this system. 相似文献