共查询到20条相似文献，搜索用时 390 毫秒
1.
The concentrations of six heavy metals (Fe, Mn, Ni, Cu, Pb and Zn) were studied in 11 hard and 4 soft common coral species
collected from Hurghada, Wadi Al-Gemal and Gola’an along the Red Sea coast to assess the differential abilities of corals
to concentrate and assimilate the heavy metals inside soft coral tissues and hard coral skeletons. These results reveal the
order of Fe > Zn > Ni > Pb ≥ Mn > Cu. Fe recorded significant high concentrations in mushroom (funnel) forms of the soft corals
at the different sites; 125.19, 101.71 and 90.44 ppm at Gola’an, Hurghada and Wadi Al-Gemal, respectively. The soft coral
species recorded the highest average concentration of Mn, Ni, Cu and Zn than the hard corals, which were 13.22, 16.05, 13.08
and 148.17 ppm, respectively. Generally, soft corals show higher metal concentrations than the hard ones; moreover, Hurghada
recorded a higher trend of metal concentrations in soft and hard corals than the other sites. The study concluded that many
biological and local environmental factors influenced the metal occurrences and uptakes in both coral forms such as, the exposed
surface area for metal uptake, turbidity, overlying mucus thickness and the ability of metals to substitute inside the crystal
lattice of the hard corals. 相似文献
2.
Saber Al-Rousan Rasheed Al-Shloul Fuad Al-Horani Ahmad Abu-Hilal 《Environmental Earth Sciences》2012,67(7):2003-2013
The concentrations of six heavy metals were studied in five living coral species and their fossil counterparts collected along the Jordanian Coast of the Gulf of Aqaba. The study aimed at investigating the validity of using coral skeletons as bioindicators for environmental pollution by heavy metals in the Gulf of Aqaba, Red Sea. The skeletal samples of the collected corals were acid digested and analyzed for Cd, Cu, Fe, Mn, Pb, and Zn content using flame atomic absorption spectrophotometer. The results obtained have shown that higher concentrations of heavy metals were found in coral skeletons from areas hosting intense developments and human activities. The massive Porites sp. coral tended to accumulate the highest metal concentrations among the other species (except for Mn). This was due to interspecific differences or selectivity of heavy metals between different coral species. It was noteworthy that fossil coral species recorded higher average metal concentrations than their living counterparts; this was attributed to surface contamination due to prolonged burial of the fossil corals in sediment over the years. The study concluded that corals (specially the massive Porites species) are vulnerable to the accumulation of high concentrations of heavy metals in their skeletons and therefore can serve as proxies to monitor environmental pollution. 相似文献
3.
太湖沉积物和湖岸土壤的污染元素特征及环境变化效应 总被引：38，自引：3，他引：38
太湖沉积物和湖岸土壤具有相似的物质组成，具有相同的物源，通过补给区的径流，营养元素和重金属元素随着土壤迁入湖泊，由于沉积物和土壤物化条件的不同，它们的营养元素和重金属含量有差异。土壤中氮，磷的总量和有效态均比沉积物中高，表明有一部分营养物质进入了水体；营养元素高的沉积物均靠近城镇，其原因为居民生活污水排放，土壤和沉积物中多数重金属元素尚未超过自然背景值，只有沉积物中Cd和Pb，土壤中的Cu,Cd和Hg超过，但沉积物中重金属元素大多比土壤中高，特别在北部沿岸沉积物中，重金属元素含量大大超过平均值，这种不正常的高值是由人类不合理的废水，废物敢排放引起。 相似文献
4.
Jorge Marcovecchio Sandra Botté Melisa Fernández Severini Federico Delucchi 《Aquatic Geochemistry》2010,16(2):251-266
Chromium and lead concentrations and distribution have been fully studied within Bahía Blanca estuary inner area, which is
strongly influenced by urban and industrial stress. Not only metals dissolved in estuarine water but also those included in
sediments and suspended particulate matters (SPM) were measured. In all cases, internationally standardized protocols were
applied to metal measurements, including analytical quality check test through analysis of certified reference materials.
Total metal contents from surface sediments and SPM were compared with those from a historical database of the area, as well
as with values representing the natural geochemical baseline within the system. Results showed that heavy metal pollution
is mainly localized in the areas close to both industrial effluents discharge system and urban sewage outfall discharge. Data
from sequential extractions indicate that metals from anthropogenic sources (i.e., Pb) are potentially more mobile than those
inherited from geological parent material (i.e., Cr). The influences of other potential sources of metals (i.e., streams,
runoff) were also considered. SPM was clearly identified as the main carrier of the studied heavy metals within the system,
and its significance to metals input into sediments and/or biota was verified. Finally, the normalization of measured metal
concentrations against background reference elements (i.e., Al or Fe) has allowed to identify that most of the measured Cr
was lithogenic, while a significant percentage of Pb was from anthropogenic origin within Bahía Blanca estuary. 相似文献
5.
The study focuses on the lateral distribution and the environmental geochemistry of seven heavy metals: Fe, Mn, Cu, Co, Ni, Pb, and Zn in addition to Al in the stream sediments of Wadi Allaqi. Forty-two samples were collected from the upstream, the midstream, and the downstream of this Wadi. Results of the grain size analysis show that the sediments of Wadi Allaqi are fine to medium sand. The heavy metals content reflects the weathering impact on the hinterland. The highest concentrations of Fe, Al, Mn, Cu, Pb, and Zn are recorded in the midstream that is dominated by clastics of felsic and intermediate composition. Moreover, the downstream, occupied by ultrabasic–basic rocks, shows the highest averages of Co and Ni. These results suggest that the felsic and intermediate rocks are the main source of the former metals, whereas the ultrabasic–basic rocks are the source of later two metals. All the analyzed heavy metals have average concentrations lower than their backgrounds, except for Co and Pb. The pollution level by these heavy metals has been evaluated using enrichment ratio (ER), pollution load index (PLI), and index of geoaccumulation (Igeo). The calculated values of ER, CF, PLI, and Igeo indicate that Wadi Allaqi sediments are almost pristine except occasional feeble pollution level by Co and Pb. 相似文献
6.
内海湾底泥沉积物的环境质量状况与水生生物的生存和人体健康关系密切。在广东汕头市内海湾两岸23个点位采集了表层(0~20 cm)和深层(100~120 cm)底泥沉积物样品46件,对其pH值和Cd、Hg、As、Pb、Cr、Cu、Zn计7项重金属及K含量进行测试分析,调查底泥中这些重金属的含量特征,并参照农用地水田土壤污染风险管控标准对重金属环境污染质量进行评价。结果表明汕头内海湾底泥沉积物的pH介于7.00~8.82之间,平均值为7.83,在46件样品中41件样品的pH值大于7.5。内海湾底泥中7项重金属元素的含量均明显低于环境污染风险管制值,即对该区底泥重金属环境污染不需要管制。Cd、As、Pb、Cr这4项重金属含量均低于污染风险筛选值,其污染风险可以忽略。2件表层样品的Hg含量值高于污染风险筛选值,18件样品的Cu和Zn含量值高于污染风险筛选值,因此建议对底泥中Cu、Zn、Hg含量进行环境质量监测。K含量介于0.70%~2.59%,平均值为1.54%。基于表层底泥和深层底泥元素含量对比分析,认为该区Hg污染来源应为人为源;Cu、Zn的污染来源一部分为人为源,另一部分可能为人为源、自然源或二者的混合源。 相似文献
7.
8.
Alessandro Amorosi Irene Sammartino Giovanni Sarti 《Environmental Earth Sciences》2013,69(5):1661-1671
Identification of reliable background values of potentially toxic metals in sediments requires detailed integration of geochemical data with accurate sedimentological studies. Through analysis of 60 soil samples from the Pisa coastal plain, this study shows to what extent sediment provenance and facies characteristics may influence the natural distribution of potentially toxic metals (Cr, Ni, Cu, Zn, Pb) within alluvial and coastal sediments. Metals supplied to the alluvial plain are mostly concentrated within the finest sediment fraction (floodplain clays), while coarser crevasse and overbank deposits exhibit invariably lower metal contents. Beach-ridge sands display the lowest metal concentrations. Transport of ophiolitic detritus by the longshore drift may account for locally high Cr concentrations within beach deposits. Geochemical fingerprinting of individual facies associations in terms of natural metal contents results in the construction of a geologically-based geochemical map. This map offers a more reliable depiction of spatial distribution of background levels than interpolation techniques based uniquely upon statistical methods. Matching background values against metal concentrations from topsoil samples leads to the reliable assessment of the pollution status of Pisa coastal plain. Metal contents exceeding the threshold values designated for contaminated areas (Cr) simply reflect catchment geology, and are not the product of artificial contamination. On the other hand, anthropogenic disturbance may be detected even where metal contents (Pb, Cu) lie below the threshold values. The use of sedimentological criteria is presented here as a pragmatic tool to enhance predictability of natural metal contents in sediments, with obvious positive feedbacks for legislative purposes and environmental protection. 相似文献
9.
Distribution and immobilization of heavy metals in Pliocene aquifer sediments in Wadi El Natrun depression, Western Desert 总被引：2，自引：0，他引：2
The Pliocene aquifer receives inflow of Miocene and Pleistocene aquifer waters in Wadi El Natrun depression. The aquifer also receives inflow from the agricultural activity and septic tanks. Nine sediment samples were collected from the Pliocene aquifer in Wadi E1 Natrun. Heavy metal (Cu, Sr, Zn, Mn, Fe, Al, Ba, Cr, Ni, V, Cd, Co, Mo, and Pb) concentrations of Pliocene aquifer sediments were investigated in bulk, sand, and mud fractions. The determination of extractable trace metals (Cu, Zn, Fe, Mn, and Pb) in Pliocene aquifer sediments using sequential extraction procedure (four steps) has been performed in order to study environmental pathways (e.g., mobility of metals, bounding states). These employ a series of successively stronger chemical leaching reagents which nominally target the different compositional fractions. By analyzing the liquid leachates and the residual solid components, it is possible to determine not only the type and concentration of metals retained in each phase but also their potential ecological significance. Cu, Sr, Zn, Mn, Fe, and Al concentrations are higher in finer sediments than in coarser sediments, while Ba, Cr, Ni, V, Cd, Co, Mo, and Pb are enriched in the coarser fraction. The differences in relative concentrations are attributed to intense anthropogenic inputs from different sources. Heavy metal concentrations are higher than global average concentrations in sandstone, USEPA guidelines, and other local and international aquifer sediments. The order of trace elements in the bulk Pliocene aquifer sediments, from high to low concentrations, is Fe?>?Al?>?Mn?>?Cr?>?Zn?>?Cu?>?Ni?>?V?>?Sr?>?Ba?>?Pb?>?Mo?>?Cd?>?Co. The Pliocene aquifer sediments are highly contaminated for most toxic metals, except Pb and Co which have moderate contamination. The active soluble (F0) and exchangeable (F1) phases are represented by high concentrations of Cu, Zn, Fe, and Mn and relatively higher concentrations of Pb and Cd. This may be due to the increase of silt and clay fractions (mud) in sediments, which act as an adsorbent, retaining metals through ion exchange and other processes. The order of mobility of heavy metals in this phase is found to be Pb?>?Cd?>?Zn?>?Cu?>?Fe?>?Mn. The values of the active phase of most heavy metals are relatively high, indicating that Pliocene sediments are potentially a major sink for heavy metals characterized by high mobility and bioavailability. Fe–Mn oxyhydroxide phase is the most important fraction among labile fractions and represents 22% for Cd, 20% for Fe, 11% for Zn, 8% for Cu, 5% for Pb, and 3% for Mn. The organic matter-bound fraction contains 80% of Mn, 72% of Cu, 68% of Zn, 60% of Fe, 35% of Pb, and 30% of Cd (as mean). Summarizing the sequential extraction, a very good immobilization of the heavy metals by the organic matter-bound fraction is followed by the carbonate-exchangeable-bound fraction. The mobility of the Cd metal in the active and Fe–Mn oxyhydroxide phases is the highest, while the Mn metal had the lowest mobility. 相似文献
10.
陕西潼关金矿区太峪河底泥重金属元素的含量及污染评价 总被引：3，自引：1，他引：2
通过对潼关金矿区太峪河和太峪水库底泥中重金属元素总量的调查,探讨了金矿开发活动中重金属元素对河流底泥的污染程度。研究结果表明,除As外,河流底泥中重金属元素的含量与尾矿渣中重金属元素的含量变化一致,表明其主要来源于尾矿渣,但又明显高于尾矿渣。在同一地点河流底泥中重金属元素的含量平均高出河水中的1048.61～666030.08倍,呈显著富集。以邻近地区不受工矿活动影响的河流底泥重金属元素的含量均值作为评价参比值,太峪河底泥受到了Hg、Pb、Cd、Cu、Zn元素的极度污染,单项污染超标倍数及综合污染指数法评价结果表明,Hg、Pb、Cd平均污染超标倍数达366.90、217.42和149.97,是底泥中最主要的污染元素。河流底泥重金属元素的综合污染指数高达278.97,表明河流的复合污染亦呈极度状态。太峪河底泥受重金属元素极度污染的现实提示,矿区的环境防治工作已刻不容缓。 相似文献
11.
In order to assess the pollution levels of selected heavy metals, 45 bottom sediment samples were collected from Al-Kharrar lagoon in central western Saudi Arabia. The concentrations of the heavy metals were recorded using inductively coupled plasma-mass spectrometer (ICP-MS). The results showed that the concentrations of Pb and Cd exceeded the environmental background values. However, the heavy metal contents were less than the threshold effect level (TEL) limit. The concentrations of heavy metals in lagoon bottom sediments varied spatially, but their variations showed similar trends. Elevated levels of metals were observed in the northern and southern parts of the lagoon. Evaluation of contamination levels by the sediment quality guidelines (SQG) of the US-EPA revealed that sediments were non-polluted-moderately to heavily polluted with Pb; non-polluted to moderately polluted with Cu; and non-polluted with Mn, Zn, Cd, and Cr. The geoaccumulation index showed that lagoon sediments were unpolluted with Cd, Mn, Fe, Hg, Mo, and Se; unpolluted to moderately polluted with Zn and Co; and moderately polluted with Pb, Cr, Cu, and As. The high enrichment factor values for Pb, As, Cu, Cr, Co, and Zn (>2) indicate their anthropogenic sources, whereas the remaining elements were of natural origins consistent with their low enrichment levels. The values of CF indicate that the bottom sediments of Al-Kharrar lagoon are moderately contaminated with Mn and Pb. 相似文献
12.
Heavy metal contamination and their distribution in different size fractions of the surficial sediment of Haihe River, China 总被引：3，自引：0，他引：3
Heavy metal contamination and their distribution in different size fractions of the surficial sediment in Haihe River, China have been investigated. These results reveal that the heavy metal contamination of Haihe River is closely related to the contaminating sources along the river and has the order: Cd > Cu > Pb > Cr. The contents of these heavy metals in the sediment of Haihe River are at least two times higher than their background values and the highest contaminating metal, Cd, is 15.5 times higher than its background value and determined in the urban area of Tianjin city. The surficial sediments of Haihe River, with 70% particles smaller than 20 μm, belong to sandy clay containing about 28% clay and 42% silt. Electron micrographs and x-ray analysis show that the concentrations of heavy metals depend on the particle size of sediments. The highest concentrations for most metals exist in fine-grained sediments, which are mainly composed of silicates, oxides, and hydroxides of Si, Fe, and Al. In contrast, lower levels of heavy metals are usually found in the coarse sandy sediments, which are composed of quartz, feldspar, and other rocky substances. Based on the results in the present study of the surficial sediments of Haihe River, the contents of Cr, Cu, Pd, and Cd in finer sediments are 2.4, 3.9, 2.8, and 3.6 times higher than those in coarse sandy sediments, respectively. Obviously, because of rapid industrial development in this area during the last few decades, the surficial sediments of Haihe River, especially those finer fractions, have been seriously contaminated by heavy metals. 相似文献
13.
This study focused on the influence of base metal mining on heavy metal levels in soils and plants in the vicinity of Arufu lead-zinc mine, Nigeria. Soil samples (0-15 cm depth) and plant samples were collected from cul-tivated farmlands in and around the mine, the unmineralized site and a nearby forest (the control site). The samples were analyzed for heavy metals (Fe, Zn, Mn, Cu, Pb, Cr and Cd) by Atomic Absorption Spectrophotometry (AAS). The physical properties of soils (pH and LOI) were also measured. Results showed that soils from cultivated farm-lands have neutral pH values (6.5-7.5), and low organic matter contents (10%). Levels of Zn, Pb and Cd in culti-vated soils were higher than the concentrations obtained from the control site. These heavy metals are most probably sourced from mining and agricultural activities in the study area. Heavy metal concentrations measured in plant parts decreased in the order of rice leavescassava tuberspeelings. In the same plant species, metal levels decreased in the order of ZnFeMnCuPbCrCd. Most heavy metals were found in plant parts at average concentrations normally observed in plants grown in uncontaminated soil, however, elevated concentrations of Pb and Cd were found in a few cassava samples close to the mine dump. A stepwise linear regression analysis identified soil metal contents, pH and LOI as some of the factors influencing soil-plant metal uptake. 相似文献
14.
Huan-Guang Deng Ju Zhang Dong-Qi Wang Zhen-Lou Chen Shi-Yuan Xu 《Environmental Earth Sciences》2010,60(1):57-63
Zn, Cu, Cr and Pb concentrations of the sediment collected from three tidal flat sites of Yangtze estuary were investigated
in October 2003. Results showed that the average concentrations of heavy metals in the sediments were two to three times to
the environment background values of Yangtze estuary tidal flat sediment. The heavy metal concentrations in the sediments
near the Bailonggang (BLG) and Laogang (LG) sewage outfalls were obviously higher than those of Chaoyang (CY) tidal flat where
there are no sewage outfalls near the coast. And the concentrations of heavy metals in the surface sediments of LG tidal flat
decreased with the increasing of the distance to the sewage outfalls. The heavy metal concentration profile in the sediment
core changed with the depth, and generally reached maximum values at the depth of plant roots. The assessment results showed
that the sediments of LG, BLG and CY tidal flat had been polluted by heavy metals in different level. The pollution degree
of heavy metals in the sediments was as follows: Zn > Cu > Pb > Cr. The potential ecological risks of the four heavy metals
in three tidal flat sites sediment were all at a middle level, and Cu and Pb made the main contributions. The adverse ecological
effects caused by the four heavy metals did not occur frequently. 相似文献
15.
Sixty-five sediment samples and 25 water samples were collected from Al-Mujib reservoir, central Jordan, in order to investigate
the heavy metal and ionic contamination assessment. Therefore, to achieve this aim, water and sediment samples were collected
during winter and summer seasons (2007) from Al-Mujib reservoir and the areas surrounding it. The study shows that there are
elevated levels of SO4
2−, Cl− and Na+ in reservoir water, which might originate from anthropogenic activities in the reservoir catchment area. In addition, the
reservoir water has higher total hardness (TH) values together with high Ca and Mg contents. This might be attributed to pH
of reservoir water and the nature of the rocks exposed in the catchment area. The average levels of heavy metals in reservoir
sediments are Fe = 14,888.1, Cu = 17.8, Zn = 88.6, Ni = 38.7, Cd = 4.4, Mn = 337.9 and Pb = 6.1 mg/kg, which are lower than
that observed in Wadi Al-Arab reservoir, northern Jordan. The values of enrichment factor are Cd = 35.5, Ni = 3.02, Zn = 2.54,
Cu = 1.26, Mn = 1.2 and Pb = 0.57; these values indicate that heavy metals in sediments of Al-Mujeb reservoir have a different
anthropogenic incrimination inputs. The study showed that the sediments are polluted with Cd, relatively contaminated with
Ni and Zn and uncontaminated with respect to Mn, Pb and Cu. 相似文献
16.
Concentrations of Fe, Mn, Zn, Cu, Pb, Ni, and Cd were measured in several species and genera of Recent benthic foraminifera
from three coastal lagoons, namely Abu-Shaar, Umm al-Huwaytat, and Marsa Shuni lagoons located along the Egyptian Red Sea
coast. Spatially significant differences in the metal concentrations of benthic foraminifera were recorded among different
sites. However, some foraminiferal species display deformation in their coiling, general shape of chambers and the apertures.
Abu-Shaar and Umm al-Huwaytat lagoons are virtually influenced by anthropogenic activities while Marsa Shuni lagoon is affected
by natural inputs. Benthic foraminifer shows high concentrations of Fe and Mn, especially in Umm al-Huwaytat lagoon. Foraminiferal
black tests support this result and reflect selectivity for iron absorption. Among the metals analyzed, Cd, Pb, and Cu showed
significant high concentrations in benthic foraminifera at the study areas. The anthropogenic activities and natural inputs
are responsible for the abnormalities in benthic foraminifera. Therefore, benthic foraminifera can be used as a good indicator
of the environmental changes. 相似文献
17.
以浙江沿海表层沉积物为研究对象,系统地研究了重金属有效结合态与沉积环境、矿物组成和人为排放等环境因素之间的相互关系.结果表明:沿海表层沉积物中重金属的积累数量,呈现出潮汐河口沉积物>沿海沉积物>强潮汐河口沉积物的趋势,这反映了不同沉积类型对重金属富集作用的差异;重金属的有效结合态,总体上以铁锰氧化物结合态>碳酸盐结合态>硫化物及有机结合态>可交换态的顺序存在,但是不同的重金属或同种重金属在不同的采点,主要有效结合态的比例存在明显的差异,这不仅与重金属的地球化学性质、沉积环境和沉积物中的粘土矿物组成有关,更受到重金属污染物的人为排放量的影响. 相似文献
18.
19.
The presence of heavy metal concentrations was examined in natural sediments from four sites along the Jajrood river in northeast
of Tehran, the capital of Iran. Besides determination of elemental concentrations (Pb, Cu, Zn, Cd, Ni and Cr), X-ray fluorescence
and X-ray diffraction tests were carried out to determine other chemical components in these adsorbents. Also the ability
of sediments to adsorb these heavy metal ions from aqueous solutions was investigated. Results show that the extent of adsorption
increases with increase in adsorbent concentration. The amount of adsorbed Pb, Cu and Zn in sediments was much greater than
that of the other metals, and Cr was adsorbed much less than others. The adsorbabilities of sediments to heavy metals increased
in the order of Pb > Cu > Zn > Cd > Ni > Cr. Based on the adsorption data, equilibrium isotherms were determined at selected
areas to characterize the adsorption process. The adsorption data followed Freundlich and Langmuir isotherms in most cases.
Correlation and cluster analysis was performed on heavy metals adsorption and sediment components at each site to evaluate
main adsorbing compounds in sediments for each metal. Results demonstrated that heavy metals sorption is mostly related to
load of organic matter in the Jajrood river sediments. 相似文献
20.
Analysis of coral reef species enables characterization of the coral reefs and the degree to which human activities influence the reef composition. Geochemical characteristics, X-ray diffraction, and natural radionuclides analyses of four common coral reef species representing the branching and massive forms were conducted at the three areas under threat (Quseir Harbor, Safaga Harbor, and El-Esh area) along the Red Sea coast. Branching recorded higher carbonates and lower organic matter than the massive forms. Stylophora pistillata at Safaga Harbor and El-Esh area and Acropora humilis at Qusier Harbor recorded the highest carbonate percentages (96.88, 96.24, and 96.89%, respectively) meanwhile Platygyra daedalea at Safaga Harbor recorded the highest organic matter contents (5.07 and 4.91%). The highest Ca contents were observed in S. pistillata and Porites solida (65.87 and 64.87%), the highest Mg was in Acropora humilis and P. daedalea (1.06 and 0.88%) at Qusier Harbor, whilst the highest Sr was in S. pistillata and P. daedalea at Safaga Harbor. Then highest value of 226Ra recorded in A. humilis and P. solida (71 ± 3.5 Bq/kg and 63 ± 3.1 Bq/k) and 232Th in S. pistillata at El-Esh area may attribute to petroleum exploration activities. A. humilis and P. daedalea at Safaga Harbor recorded significant high 40K values (505 ± 30 and 472 ± 13 Bq/kg, respectively) relative to the other localities. The low Ca and High Sr as well as the highest averages of 232Th and 40K at Safaga Harbor indicated that the coral reef communities were highly affected by the terrestrial inputs from phosphate shipments. 相似文献