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1.
The Gulf of Mannar along the Tuticorin coast is a coral base of the southeast coast of India. To obtain a preliminary view of its environmental conditions, geochemical distribution of major elements (Si, Al, Fe, Ca, Mg, Na, K, P), trace elements (Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd) and acid leachable elements (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd) were analyzed in surface sediment samples from two seasons. Geochemical fractionation confirmed the lithogenic origin of metals, which were mainly associated with the detrital phase. The sediments in the gulf are sandy with abundant calcareous debris, which controls the distribution of total and acid leachable elements. Enrichment factors relative to crust vary by a magnitude of two to three and the presence of trace metals indicates the input of Cr, Pb, Cd, Cu and Zn in both forms through industrial activities. Factor analysis supports the above observation with higher loadings on acid leachable elements and its association with CaCO3. The increase in concentration of trace metals (Cr, Pb, Cd, Cu, Co, Ni, Zn) along the Gulf of Mannar indicates that the area has been contaminated by the input from riverine sources and the industries nearby. The present study indicates that other sources should be evaluated in the long-term monitoring program.  相似文献   

2.
Grain size parameters, trace metals (Co, Cu, Ni, Pb, Cr, Zn, Ba, Zr and Sr) and total organic matter (TOM) of 38 surficial sediments and a sediment core of west-four Pearl River Estuary region were analyzed. The spacial distribution and the transportation procession of the chemical element in surficial sediments were studied mainly. Multivariate statistics are used to analyses the interrelationship of metal elements, TOM and the grain size parameters. The results demonstrated that terrigenous sediment taken by the rivers are main sources of the trace metal elements and TOM, and the lithology of parent material is a dominating factor controlling the trace metal composition in the surficial sediment. In addition, the hydrodynamic condition and landform are the dominating factors controlling the large-scale distribution, while the anthropogenic input in the coastal area alters the regional distribution of heavy metal elements Co, Cu, Ni, Pb, Cr and Zn. The enrichment factor (EF) analysis was used for the differentiation of the metal source between anthropogenic and naturally occurring, and for the assessment of the anthropogenic influence, the deeper layer content of heavy metals were calculated as the background values and Zr was chosen as the reference element for Co, Cu, Ni, Pb, Cr and Zn. The result indicate prevalent enrichment of Co, Cu, Ni, Pb and Cr, and the contamination of Pb is most obvious, further more, the peculiar high EF value sites of Zn and Pb probably suggest point source input.  相似文献   

3.
To assess heavy metals in mangrove swamps of Sehat and Tarut coastal areas along the Arabian Gulf, 18 sediment samples were collected for Al, V, Cr, Mn, Cu, Zn, Cd, Pb, Hg, Sr, As, Fe, Co, and Ni analysis. The results indicated that the distribution of some metals was largely controlled by anthropogenic inputs, while others were of terrigenous origin and most strongly associated with distribution of aluminum and total organic carbon in sediments. Mangrove sediments were extremely severe enriched with Sr (EF?=?67.59) and very severe enriched with V, Hg, Cd, Cu, As (EF?=?44.28, 37.45, 35.77, 25.97, and 11.53, respectively). Average values of Sr, V, Hg, Cd, Cu, Ni, As, and Cr were mostly higher than the ones recorded from the Mediterranean Sea, the Red Sea, the Gulf of Aqaba, the Caspian Sea, the Arabian and Oman gulfs, coast of Tanzania, sediment quality guidelines, and the background shale and the earth crust. Landfilling due to coastal infrastructure development around mangrove forests, oil spills and petrochemical and desalination effluents from Al-Jubail industrial city to the north were the anthropogenic activities that further enhanced heavy metals in the studied mangrove sediments.  相似文献   

4.
太平洋北部铁锰结核富集区沉积物的元素地球化学特征   总被引：2，自引：1，他引：2  
鲍根德 《沉积学报》1990,8(1):44-56
本文对太平洋北部铁锰结核富集区沉积物的元素地球化学作了较为详细的研究。因子分析提供的信息表明,元素的分布主要受三个因子控制:（1）粘土及Fe、Mn氧化物水化物胶体的吸附作用;（2）生物化学作用过程有关的自生沉积作用;（3）海底页岩风化及附近海区的火山喷发作用。元素的来源:（1）Fe、Mn、Cu、Co、Ni、Zn、Cr、Cr、Mg、Al、Ti、K共生,主要来自粘土吸附;（2）C有机、N、Sr、Na及Si、Ca、Sr主要来自生物化学过程沉积;（3）Pb主要来源于岩石碎屑（火山喷发碎屑）。  相似文献   

5.
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   

6.
Four overbank profiles from the three terraces of different age were sampled in 10 to 20 cm intervals for the bulk content of major and minor (Ca, Mg, Fe, Ti, Al, Na, K and P) and trace (Mo, Cu, Pb, Zn, Ni, Co, Mn, As, U, Th, Sr, Cd, Sb, V, La, Cr, Ba, W, Zr, Ce, Sn, Y, Nb, Ta, Sc, Li, Rb and Hf) elements in the minus 0.125 mm fraction. Univariate statistics together with analysis of variance discriminated between the lower-lying carbonate (CA) population dominantly composed of carbonates and the overlying silicate (SI) population being dominantly of silicate mineralogy. This stratified pattern resulted from the intensive erosive action of melting glaciers exerted on limestones and dolomites in the alpine region, followed by local inputs mainly of silicate composition. Elements exhibiting the greatest between-population variability are Ca and Mg being enriched in the CA population and Fe, Mn, P, Sr, Al, Na, K, Li, Rb, Y, Zr, Ni, Cr and Ti being enriched in the SI population. Anomalously high Hg, Pb and Ba concentrations (maximum values: 6,500±2,860 ppb, 225±13 ppm and 1,519±91 ppm, respectively) in the lowermost part of the profile S7, which is nearest to the Croatian-Slovenian border, derive from the mineralized Slovenian catchment area. This profile also contains trimodal frequency distributions of Fe, Mn and P whose highest concentrations coincide with increased values of Zn and Cu which are bimodally distributed. Geochemical patterns of majority of elements in all four profiles consistently reflect the average compositions of the upstream drainage basins.  相似文献   

7.
The present study to find seasonal (September 2010–June 2011) heavy metal (Cd, Pb, Cr, Co, Ni, Zn, Cu, Fe, As) contamination and the origins thereof in surface sediments of Gökçekaya Dam Lake, as constructed on Sakarya River, the third-longest river in Turkey and the largest river of the Northwestern Anatolia. Upon analyses for the purpose thereof, heavy metal contamination in annual average concentrations in the lake sediment varied, respectively, as Fe > Zn > Cr > Ni > Cu > Pb > Co > As > Cd. Statistical assessments performed in order to see whether the average values of the heavy metal contamination as measured at stations placed in the lake changed by seasonal periods. There found statistically significant differences especially in Cd, Zn, and Pb between seasonal periods. In accordance with the Sediment Quality Index, Gökçekaya Dam Lake sediment was classified as “highly polluted” in terms of the amount of anthropogenic contaminants of As, Cr, Cu, Ni, Pb, and Zn. Enrichment factor and geoaccumulation index values (I geo) were calculated in order to geochemically interpret the source of contamination due to heavy metal concentration in the lake sediment and the level of pollution. The As, Co, Cr, Cu, Ni Pb, and Zn values demonstrated that the sediment was rich for anthropogenic contaminants. The lake was found especially rich for arsenic (14.97–34.70 mg/kg) and lead (68.75–98.65 mg/kg) in accordance with annual average values. In general the lake was geochemically characterized as “moderately contaminated” in terms of As, Co, Cr, Cu, Ni, Pb, and Zn content.  相似文献   

8.
《Applied Geochemistry》2005,20(1):69-88
Surface sediments of the NW Aegean Sea were analyzed for clay mineral composition (94 samples), organic C and carbonate content, and major and minor elements (112 samples). Illite is the most abundant clay mineral, followed by smectite, chlorite and kaolinite. Clay minerals are preferentially deposited within the continental shelf and slope environment, due to the prevailing cyclonic circulation and the formation of flocs in the rivers’ pro-delta areas. The spatial distribution of major lithogenic elements (Si, Al, Ti, Fe) is substantially biased by the presence of relict sands located in the central-eastern part of the Thermaikos Gulf continental shelf. Biogenic elements (Ca, Sr) are noticeably pronounced on the northern flank of the North Sporades Islands. Organic C content and minor elements Cu, Zn, As and Pb are enriched markedly over the Thessaloniki Bay and Gulf suggesting substantial human impact, deriving largely from untreated or partly treated domestic and industrial effluents. The terrigenous component of the elements is preferentially contributed from the Axios River (Zn and Pb), the Aliakmon River (Cr, Co, Ni, Cu and As), and to a lesser extent from the Pinios River (V, Co, Ni and Cu); a considerable part of the metals originates in ultra-mafic and volcanic formations, which are abundant in the rivers’ catchment basins. Carbonate content exhibits great variability, with the highest values observed in biogenic sediments of the Sporades Basin. In the latter area, Mn (and Fe) oxides and hydroxides were found as coatings on calcite. The coatings were enriched in Cr, Co, Ni, Zn, As, Mo and Pb, due to adsorption or ion-exchange during early diagenesis. The combined influence of the river systems, the Thessaloniki metropolis, and the diverse sedimentological background, generates great patchiness in the distribution of major and minor elements.  相似文献   

9.
Surface slices of 20 sediment cores, off southwestern Taiwan, and bed sediment of River Kaoping were measured for major and trace elements (Al, As, Ca, Cd, Cl, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Si, Ti, V, and Zn) to evaluate the geochemical processes responsible for their distribution, including elemental contamination. Major element/Al ratio and mean grain size indicate quartz-dominated, coarse grained sediments that likely derived from sedimentary rocks of Taiwan and upper crust of Yangtze Craton. Bi-plot of SiO2 versus Fe2O3T suggests the possible iron enrichment in sediments of slag dumping sites. Highest concentrations of Cr, Mn, P, S, and Zn found in sediments of dumping sites support this. Correlation analysis shows dual associations, detrital and organic carbon, for Cr, P, S, and V with the latter association typical for sediments in dumping sites. Normalization of trace elements to Al indicates high enrichment factors (>2) for As, Cd, Pb, and Zn, revealing contamination. Factor analysis extracted four geochemical associations with the principal factor accounted for 25.1% of the total variance and identifies the combined effects of dumped iron and steel slag-induced C–S–Fe relationship owing to authigenic precipitation of Fe–Mn oxyhydroxides and/or metal sulfides, and organic matter complexation of Fe, Mn, Ca, Cr, P, and V. Factors 2, 3, and 4 reveal detrital association (Ti, Al, Ni, Pb, Cu, and V), effect of sea salt (Cl, Mg, Na, and K) and anthropogenic component (As and Zn)-carbonate link, respectively, in the investigated sediments.  相似文献   

10.
Nador lagoon sediments (East Morocco) are contaminated by industrial iron mine tailings, urban dumps and untreated wastewaters from surrounding cities. The lagoon is an ecosystem of biological, scientific and socio-economic interests but its balance is threatened by pollution already marked by biodiversity changes and a modification of foraminifera and ostracods shell structures. The aim of the study is to assess the heavy metal contamination level and mobility by identifying the trapping phases. The study includes analyses by ICP-AES and ICP-MS, of, respectively, major (Si, Al, Mg, Ca, Fe, Mn, Ti, Na, K, P) and trace elements (Sr, Ba, V, Ni, Co, Cr, Zn, Cu, As, Pb, Cd) in sediments and suspended matter, heavy metals enrichment factors calculations and sequential extractions. Results show that sediments contain Zn, Cu, Pb, V, Cr, Co, As, Ni with minimum and maximum concentrations, respectively, of 4–1190 μg/g, 4–466 μg/g, 11–297 μg/g, 11–194 μg/g, 9–139 μg/g, 1–120 μg/g, 4–76 μg/g, 2–62 μg/g. High concentrations in Zn are also present in suspended matter. The enrichment factors show contamination in Zn, Pb and As firstly induced by the mining industry and secondly by unauthorized dumps and untreated wastewaters. Cr and Ni are bound to clays, whereas V, Co, Cu and Zn are related to oxides. Thus, the risk in metal mobility is for the latter elements and lies in the oxidation–reduction-changing conditions of sediments.  相似文献   

11.
The concentrations of metals (Cd, Pb, Ni, Cr, Cu, Fe, Mn and Zn) were determined in soils under different land use types in an urban environment in order to study the impact of land uses on the concentrations of metals in the soils. The mean concentration range of metals for all land use types were 42.1 to 410, 11.2 to 118.2, 4388.2 to 31891.1, 9.7 to 65.4, 0.1 to 1.8, 4.7 to 35.2, 2.0 to 16.8 and 77.9 to 881.7 mg/kg, for Mn, Pb, Fe, Cu, Cd, Cr, Ni and Zn, respectively. The computed multiple pollution index (MPI) indicated that 67 % of the examined sites had MPI values between 1 and 20 i.e. at the pollution range, while 33 % of sites had MPI values of zero which indicated that these sites were not polluted with the studied metals. Zinc had the highest impact on the multiple pollution index values. Three main principal components were identified from the principal component analysis which include (i) Cu, Zn, Pb, Cr and Ni originating from both industrial and agricultural sources, and as well as automobile exhausts; (ii) Fe and Mn which originated from both natural and anthropogenic sources; (iii) Cd which its anthropogenic origin is different from components I and II. This study provided information on the sources of metals in the urban environment and extent of contamination associated with each land use, which are useful in the ranking of contaminated sites, environmental quality management, environmental forensic studies and guidance for remediation/redevelopment of contaminated land.  相似文献   

12.
Studies on the suspended particulate matter (SPM) in the Mandovi estuary, western India indicate that during the monsoon and pre-monsoon, the SPM increases, and the major and trace metals decrease from stations in the upstream to downstream of the estuary. SPM is consistently low at all stations during the post-monsoon. Trace metals (Cu, Ni, Zn, Cr, and Pb) show strong inter-relationships. They correlate well with Fe and Mn only during the monsoon. The concentrations of Cr, Cu, and Pb are high during the post-monsoon. Enrichment factors and I geo values of metals indicate that Mn shows significant to strong pollution in all seasons, while Cr, Ni, and Zn during monsoon, and Cr during the post-monsoon show moderate pollution. SPM is controlled by the turbidity maximum, while major and trace metals are governed seasonally by a combination of river discharge, resuspension, spillage of Fe–Mn particulates, and anthropogenic contamination. Incursion of saline waters deep into the river channel during the dry season facilitates aggregation and settling of particulate-borne pollutants close to the discharge area, thereby keeping the estuarine waters free from major contamination.  相似文献   

13.
In order to better understand the relative importance of hydrologic variation and anthropogenic disturbance and their complex interactions within the trace elemental geochemical cycle, water samples were collected monthly over 1 year in the Min River, eastern Tibetan Plateau, and analyzed for trace element composition. The dissolved trace elements exhibited different relationships with increasing discharge compared with major elements. The elements analyzed can be divided into three groups according to their behavior in response to changing discharge: (1) elements that showed weak positive correlation with discharge, e.g. Cu, V, and Ba; (2) elements that exhibited weak negative correlation with discharge, including Rb, Sr, Pb, Sb, Zn, Cr, Cd, and U; and (3) elements that displayed no significant correlation with variation in discharge, e.g. Ti, Fe, Co, Ni, and As. Cu was strongly affected by anthropogenic activities and flushed into the river with increasing discharge. Ba has a strong solubility in the terrestrial environment, dissolved quickly, and was released into the river. The positive relationship between V concentration and discharge may be attributed to secondary reactions, such as precipitation and adsorption on oxides and aluminosilicate clays. Conservative behavior had an impact on the geochemical behavior of Sr and Rb across hydrologic variation. Pb, Zn, Sb, Cd, and Cr underwent a mild dilution effect connected with anthropogenic activities. The chemostatic behavior of U was regulated by carbonate dissolution and biological uptake. In addition, higher temperatures enhanced biotic activities, affecting the concentrations of Fe and Ni. The relationship between power law slopes and coefficient of variation for discharge and solute concentration suggests that concentrations of trace elements vary significantly with increasing discharge compared with major elements. Silicate mineral weathering had less effect on the fluvial solutes with increasing discharge. Mining activity may exert an additional control on concentration–discharge dynamics of anthropogenic trace elements.  相似文献   

14.
Water, sediment, and mine spoil samples were collected within the vicinity of the Okpara coal mine in Enugu, Southeastern Nigeria, and analyzed for trace elements using ICP-MS to assess the level of environmental contamination by these elements. The results obtained show that the mine spoils and sediments are relatively enriched in Fe, with mean values of 1,307.8(mg/kg) for mine spoils and 94.15% for sediments. As, Cd, Cr, Mn,Ni, Pb, and Zn in the sediments were found to be enriched relative to the mean values obtained from the study area, showing contamination by these elements. The mean values of Fe, Mn, Cu, and Cr in the mine spoils and mean values of Fe, Cu, Pb, Zn, Ni, Cr, and Mn in sediments, respectively, are above the background values obtained from coal and shale in the study area, indicating enrichment with these elements. The water and sediments are moderately acidic, with mean pH values of 4.22?±?1.06 and 4.66?±?1.35, respectively. With the exception of Fe, Mn, and Ni, all other elements are within the Nigerian water quality standard and WHO limits for drinking water and other domestic purposes. The strong to moderate positive correlation between Fe and Cu (r?=?0.72), Fe and Zn (r?=?0.88), and Fe and As (r?=?0.60) at p?<?0.05 as obtained for the sediments depict the scavenging effect of Fe on these mobile elements. As also shows a strong positive correlation with Mn (r?=?≥ 0.70, p?<?0.05), indicating that Mn plays a major role in scavenging elements that are not co-precipitated with Fe. In water, the strong positive correlation observed between Cr and Cd (r?=?1.00), Cu and Ni (r?=?0.94), Pb and Cu (r?=?0.87) and Zn and Cu (r?=?0.99); Ni and Pb (r?=?0.83) and Zn and Ni (r?=?0.97); and between Pb and Zn (0.84) at p?<?0.05 may indicate similar element–water reaction control on the system due to similarities in chemical properties as well as a common source. Elevated levels of heavy metals in sediments relative to surface water probably imply that sorption and co-precipitation on Al and Fe oxides are more effective in the mobilization and attenuation of heavy metals in the mine area than acid-induced dissolution. The level of concentration of trace elements for the mine spoils will serve as baseline data for future reference in the study area.  相似文献   

15.
Groundwater pollution is a major global environmental issue especially in the large cities and trace metals are considered as most important aquatic pollutants. The present study is based on the measurement and characterization of various physicochemical parameters (pH, EC, TDS, DO, alkalinity, hardness, and chloride), major cations (Ca, Mg, Na and K) and selected trace metals (Sr, Li, Fe, Zn, Cu, Co, Mn, Ag, Cd, Cr, Ni, and Pb) in the groundwater of Lahore, Pakistan during summer and winter (2017–18) seasons. Groundwater is the main source of drinking water in urban areas of Lahore. Seasonal comparison of the data indicated that majority of the metals showed relatively higher concentrations during winter than summer. Most of the metals exhibited significant spatial variability during both seasons; relatively higher metal levels were found in the old settlements and thickly populated areas of the city. Average concentrations of Pb, Ni, Cd and Co in the groundwater were found to be higher than the national and international guideline values. Factor analysis and cluster analysis revealed major anthropogenic contributions of Ni, Co, Cd, Cu, Cr and Pb in the groundwater while rest of the metals showed mixed and/or natural contributions. Evaluation of human health risks for the metal contents in groundwater revealed that Pb, Co, Ni and Cd were associated with significantly higher non-carcinogenic risks (HQing > 1); the calculated risk for children was considerably higher than the adults. Moreover, the carcinogenic risk associated with Ni, Cr, Cd and Pb exceeded the safe limits. The present study revealed significantly higher anthropic pollutants in the groundwater which imposed considerable risks to human; therefore, it is recommended to implement immediate remedial measures to ensure safe drinking water.  相似文献   

16.
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   

17.
采用经验和数法校正基体效应,X荧光光谱测定样品中的主、次痕量元素是一种简便而快速的方法,但由于经验系数的求取很大程度上取决于标准样品的类型、含量范围和计算方法,往往使用范围有一定的局限性,本文提出的标准分类法计算经验系数,  相似文献   

18.
Urbanisation and industrial development lead to contamination of estuaries and streams with dispersed loadings of heavy metals and metalloids. Contributions of these elements also occur from natural sources. This study provides baseline geochemical data on the respective natural and anthropogenic inputs of Cu, Pb, Zn, Cd, As, Sb, Cr, Ni, Mn and S to estuarine, fluvial and wetland sediments, and adjacent soils, in the Kooloonbung Creek catchment that drains the Port Macquarie urban area in north coastal New South Wales. There have been anthropogenic additions of Cu, Pb, Zn and As from dispersed urban sources at Port Macquarie, but they are restricted to the local catchment and do not impact on the adjacent Hastings River estuary. The most contaminated sediments display enrichment factors up to 20 × for Cu and Pb, 9 × for Zn and 5 × for As relative to local background values. However, only one value (for Pb) exceeds National Water Quality Management Strategy interim sediment quality guideline (high) values. On the other hand, sediments and local soils are commonly strongly enriched in Cr, Ni and Mn, reflecting adjacent ultramafic and mafic rock substrate and lateritic regolith. Concentrations of Cr and Ni are commonly well above interim sediment quality guideline (high) values for sediments, but are in mineralogical forms that are not readily bioavailable. Sediment and soil quality guideline values consequently need to recognise natural enrichments and the mineralogical siting of heavy metals. Although dissolved concentrations of heavy metals in stream waters are commonly low, there is evidence for mobility of Cu, Zn, Fe and Al. Parts of the Kooloonbung Creek wetland area lie on sulfidic estuarine sediments (potential acid sulfate soils). Experimental oxidation of uncontaminated and contaminated sulfidic sediments leads to substantial dissolution of heavy metals under acid conditions, with subsequent aquatic mobility. The results warn about disturbance and oxidation of potential acid sulfate soils that have been contaminated by urban and natural heavy-metal sources.  相似文献   

19.
This study investigated the temporal variations of major and trace element contents and controlling factors in the upper reaches of the Xijiang River, SW China. The results showed the major ions principally derived from the weathering of carbonate and silicate rocks, with a seasonal variation impacted by the monsoonal climate. The contents of dissolved trace elements also varied seasonally in the two main tributaries: the Nanpan and Beipan rivers. Most dissolved trace elements such as Mn, Zn and Pb being affected by anthropogenic contributions displayed a large seasonal variability, from onefold to hundred-fold, while V, Rb and U show a relative stable trend uncorrelated with the different seasons, suggesting a natural origin by rock weathering. Suspended particle matter in the Nanpan and Beipan rivers was depleted in Ca, Mg, Na, K and Sr, but enriched in Al, Fe and Sb compared to the upper crust (UC) values. A binary mixture of silicate-rich and carbonate-rich sources dominates the behavior of elements such as Ca and Sr in riverine sediments, while a third end-member with an anthropogenic signature influenced the content of trace elements like Mn, Sb, Pb, Zn, Cd, Cr and Cu. The enrichments of Sb relative to the UC would be related to the mining activity in the studied area. The study highlights the importance of investigating temporal variations of major and trace element contents of rivers controlled by the monsoon climate and impacted by human activity.  相似文献   

20.
The degree of metal contamination (Zn, Pb, Cu, Ni, Cd) has been investigated in the vicinity of an old unmonitored municipal landfill in Prague, Czech Republic, where the leachate is directly drained into a surface stream. The water chemistry was coupled with investigation of the stream sediment (aqua regia extract, sequential extraction, voltammetry of microparticles) and newly formed products (SEM/EDS, XRD). The MINTEQA2 speciation-solubility calculation showed that the metals (Zn, Pb, Cu, Ni) are mainly present as carbonate complexes in leachate-polluted surface waters. These waters were oversaturated with respect to Fe(III) oxyhydroxides, calcite (CaCO3) and other carbonate phases. Three metal attenuation mechanisms were identified in leachate-polluted surface waters: (i) spontaneous precipitation of metal-bearing calcite exhibiting significant concentrations of trace elements (Fe, Mn, Mg, Sr, Ba, Pb, Zn, Ni); (ii) binding to Fe(III) oxyhydroxides (mainly goethite, FeOOH) (Pb, Zn, Cu, Ni); and (iii) preferential bonding to sediment organic matter (Cu). These processes act as the key scavenging mechanisms and significantly decrease the metal concentrations in leachate-polluted water within 200 m from the direct leachate outflow into the stream. Under the near-neutral conditions governing the sediment/water interface in the landfill environment, metals are strongly bound in the stream sediment and remain relatively immobile.  相似文献   

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