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1.
We tested the dynamical model of migration based on balance equations, for a predictive assessment of soil pollution by heavy metals: lead, cadmium, zinc and copper, at the level of an administrative district. As the main input components of the balance, we took into account the flows of metals caused by atmospheric depositions, weathering of parent materials and input with fertilizers (on agricultural lands); the expenditure part of the balance is described by flows of metals with the infiltration subsurface flow and consumption for buildup of the vegetation biomass or the removal with the harvest. It is found that given the continuation of the existing level of loads (scenario 1), for the calculated period (40 years) in the soils of natural ecosystems the concentrations of the four elements can decrease substantially or remain at the previous level. Changes will make up 0.2–0.8% for lead, 0.5–5 for cadmium, 0.8–4 for copper, and 0.3–1.5% for zinc of their total content levels in the soil. In the soils of agricultural lands, provided that the aforementioned conditions are observed, the total content of lead will increase by 5–6.5%, cadmium by 1–1.2%, copper by 2.1–3, and zinc by 12.5–16.5%. It is determined that with an increase in the flow of atmospheric deposition (scenario 2), for 40 years the soils of natural ecosystems will retain a minor negative balance of cadmium (0.001–0.004 mg/kg of the soil); for lead the negative balance in forest ecosystems will change to a minor positive balance (0.09–0.18 mg/kg of the soil), and the removal of zinc and copper will retain its previous level. In the soils of agricultural lands, with a simultaneous increase of the rates of application of organic fertilizers by 20%, the total concentrations of lead for the calculated period can increase by 7.1–9.6%, cadmium by 7–8.5, copper by 5.2–7.8, and zinc by 18.2–24.2%.  相似文献   

2.
We have explored the possibility of using the geochemical characteristics of migration and accumulation of alkali metals (lithium, rubidium, and caesium) as the indicators of anthropogenic status of heavy metals in bottom sediments of small rivers of a technogenically disturbed (urbanized) environment. A study was made of the behavior of the above elements in bottom sediments of the rivers of Petrozavodsk (Republic of Karelia). The chemical composition of the sediments used in the study was determined with X-ray fluorescence spectrometer ARL ADVANT’X and mass spectrometer XSeries-2 ICP-MS; the content of organic matter in bottom sediments (from the LOI index) was estimated by the weighing method upon heating the samples under investigation to the temperature of 1100°C. As a result of the investigations, it was found that among the heavy metals, Co, Ni, Cu, Zn, Mo, Sb, W and Pb are of predominantly technogenic origin in river sediments, which Cr and Cs are of predominantly natural origin due to a high background of these elements in Quaternary formations of the study area. We determined a close association of the trace elements of technogenic status as well as of Li, Rb and Cs with content levels of iron-manganese formations and organic matter in river sediments, which does indicate a commonalty of the processes promoting their input into the urban water stream. It is established that the commonalty of accumulation of a number of heavy metals in bottom sediments with lithophylic elements (Li, Rb and Cs), due to the high chemical activity of these latter, makes it possible to use the geochemical characteristics of the alkali metals as the indicator of technogenic status of the main pollutants of the urban environment.  相似文献   

3.
A study was made of the influence of extraction of lead and zinc ores in the northern part of Vietnam (the Red river basin, Chodon district of Bac Can Province, and the basins of the Dai, Ban Thi, Ta Dieng and Cau rivers). Background concentrations of macro- and microelements and biogenic elements are determined in the river waters and water extracts from bottom sediments of small streams of the study area. A significance exceedance of background concentrations was revealed in stretches of the headwaters of the Ban Thi and Dai rivers caused by a combination of natural and anthropogenic factors. It is established that the river waters near the pollution sources contain increased (compared with the geochemical background) concentrations of Zn, Pb, Fe, Ni, Co, As, Bi, Cd, Cs, Sb, Ag,NO2? and SO42?. The waters are estimated as moderately and heavily polluted, and at the other points as minimally polluted. It is determined that the level of accumulation of matter in water extracts from bottom sediments with respect to the geochemical background in the vicinity of the ore dressing factories corresponds to weakly and heavily polluted bottom sediments, and further downstream, to thy minimum level of pollution. It is shown that the influence of extraction of lead and zinc ores on the state of small streams is observed in stretches as long as 11–12 km (with a maximum in stretches of up to 4.5 km). The mathematical model of Pb and Zn distribution in the river waters of the study area has been developed and tested.  相似文献   

4.
Reservoir sediments are rarely used as environmental archives because of the potential for sediment disturbance by fluctuating water levels. However, rapid rates of sedimentation, proximity to urban centres and often the existence of management records, may make them potentially important resources for reconstructing recent, anthropogenically-derived environmental change. This project assesses the potential of reservoir sedimentary records for reconstructing past atmospheric and drainage basin fluxes of heavy metals (manganese, iron, nickel, copper, zinc and lead) in the southern Pennines, UK. Five reservoirs were selected on the basis of management history and drainage basin characteristics. Multi-parameter analysis showed sediments to be replicable across the ȁ8accumulating zone’ with reasonably consistent rates of sedimentation. Water level fluctuations were not found to detrimentally affect sediment records in the deepwater area of the reservoirs. In fact, spheroidal carbonaceous particle (SCP) profiles show trends in inputs that closely reflect major changes in industrialisation, indicating the reservoir sediments to be excellent records of particulate inputs. Only lead (Pb) and zinc (Zn) were significantly enriched in the reservoir sediment in comparison to background levels. Manganese (Mn), iron (Fe) and to a limited degree, copper (Cu), appeared to be affected by post-deposition mobility. Preliminary calculations of Pb fluxes indicate that over 80% of the current Pb input to the reservoirs is from Pb deposited onto drainage basin soils in the past, rather than from direct atmospheric deposition or natural background inputs. In Howden reservoir, for example, the total Pb flux to deepwater sediment cores in 2000 was 119 mg m−2 a−1. Of this, an estimated 99 mg m−2 a−1 was from anthropogenically-derived Pb, initially deposited onto drainage basin soils and subsequently entering the reservoir via erosion and leaching processes. There is, therefore, no indication that the flux of Pb to the aquatic system is declining in response to reductions in Pb deposition. The ecotoxicological effects of the high and continuing Pb flux to these reservoirs, despite recent decreases in atmospheric deposition, is an area requiring further investigation.  相似文献   

5.
A 157-cm-long sediment core from Longemer Lake in the Vosges Mountains of France spans the past two millennia and was analyzed for trace metal content and lead isotope composition. Trace metal accumulation rates highlight three main input phases: Roman Times (cal. 100 BC–AD 400), the Middle Ages (cal. AD 1000–1500), and the twentieth century. Atmospheric contamination displays a pattern that is similar to that seen in peat bogs from the region, at least until the eighteenth century. Thereafter, the lake sediment record is more precise than peat records. Some regional mining activity, such as that in archaeologically identified eighteenth-century mining districts, was detected from the lead isotope composition of sediment samples. Compositional data analysis, using six trace metals (silver, arsenic, cadmium, copper, lead and zinc), enabled us to distinguish between background conditions, periods of mining, and of other anthropogenic trace metal emissions, such as the recent use of leaded gasoline.  相似文献   

6.
本文研究了湘西亚热带地球化学景观上壤中重金属分布与土壤机械组成、矿物成分之间的关系。  相似文献   

7.
The hypermarine southern Coorong is threatened by proposals to drain relatively fresh surface water and groundwater from adjacent agricultural areas into the Coorong. These influent waters carry moderate loads of heavy metals. Acute toxicity of heavy metals toDiacypris compacta, an abundant ostracod in the Coorong, was measured in the laboratory at 18°C in a static system using Coorong water (pH 7.8 salinity 50 ppt). At 4 days (96 h) the mean values of LC50 for copper, zinc, lead and, cadmium respectively were 0.8, 2.1, 3.1 and 4.3 mg L–1, and at 8 days the respective mean LC50 s were 0.4, 0.7, 2.2 and 1.1 mgL–1. The effect of two or three metals on mortality was additive in some cases and synergistic in other cases, but generally less than additive. However, in all cases mortality was greater in the presence of two or three metals than in the presence of a single metal. According to ANZECC (1992) guidelines, maximum acceptable concentrations of heavy metals should be no higher than 0.01 x the lowest LC50 value. Using the lowest LC50 values forDiacypris compacta obtained at 8 days, maximum acceptable concentrations in the Coorong would be 4, 5, 9 and 22 gL–1 for copper, zinc, cadmium and lead respectively, the values for zinc and copper failling below those recommended by ANZECC (1992) for marine waters. Reported concentrations of copper and zinc in surface water and groundwater in areas adjacent to the Coorong sometimes exceed these values, hence drainage of these waters into the Coorong represents a significant hazard to the Coorong biota.  相似文献   

8.
We report the results from investigating the soils, bottom sediments and surface waters of the Vasyugan river valley for the tract from the mouth to the settlement of Katyl’ga (465 km). Specific activity levels have been ascertained for radionuclides of uranium-238, thorium-232, potassium-40 and caesium-137 in soils and bottom sediments. Silt and sandy silt sediments have a high accumulating capacity with respect to radionuclides. Petroleum products, total iron and aluminum are the main pollutants of the Vasyugan river ad its tributaries.  相似文献   

9.
Presented are the results from experimental investigations into the influence of large tributaries (the Zeya, Bureya and Sungari rivers) on the water quality formation in the Amur river during the transformation of organic matter in bottom sediments. A spectral method and biochemical indication were used to show that toxic heavy metals (mercury, lead, and cadmium) accumulate in river sections of sedimentation of suspended load forming along the right bank from the mouth of the Sungari river to the city of Komsomolsk-on-Amur, and to substantiate the risk of emergence of hydrogen sulfide zones on the lower Amur.  相似文献   

10.
Detailed stratigraphic analyses of sediments deposited in Lake Botjärnen, a small boreal forest lake in the shield terrain of central Sweden, clearly reflect progressively increasing human impact on terrestrial and aquatic ecosystems following settlement and establishment of an iron industry in the 17th century. Rising frequencies of pollen and spores from light-demanding plants provide evidence of extensive forest clearance for charcoal and timber production, which peaked in the early 20th century. An associated increase in catchment erosion is reflected by changing carbon and nitrogen elemental content and carbon–isotope composition of sediment organic matter and by increased magnetic susceptibility of the sediments. Records of air-borne pollutants (lead, zinc and sulphur) can be correlated to the development of local and regional mining and metal industry as inferred from historical accounts. Rapid recession of the iron industry led to re-forestation and recovery of the aquatic nutrient status to pre-industrial conditions over the past 100 years. The chronology of the sediment succession, which is based on 210Pb and 137Cs radionuclide data in combination with radiocarbon dating, is confirmed by historical lead pollution trends established for the region.  相似文献   

11.
破罡湖底泥重金属分布特征及潜在生态危害   总被引:1,自引:0,他引:1  
2009年7月,采用Mapinfo专题地图制作技术和Lars Hankson指数模型对破罡湖底泥中铜、铬、锌、镉和铅5种重金属污染的空间分布现状及潜在生态危害进行了研究。结果表明,①破罡湖底泥中铬、铜、锌、镉和铅的含量分别为110~145 mg/kg、51.9~68.1 mg/kg、119~155 mg/kg、1.05~1.41 mg/kg和38.0~62.1 mg/kg;其中,铜和镉的平均含量超过了《土壤环境质量标准》(GB15618-1995)二级标准限值,其他重金属平均含量则在允许范围内。②破罡湖底泥中铜与铬最大含量分布区域都出现在该湖东北部邻枞阳县处;底泥中锌和镉的分布也有一定相似性,最大锌含量和镉含量都出现在湖东北部的小合村以北处,而在湖东南部通江渠附近的锌含量和镉含量都是最小的;铜与铬和锌与镉具有协同毒性,其分布的空间重叠增加了其高含量区域的生态风险。③底泥中铅的高含量区域则出现在湖西湖滨带,汽车尾气排铅是破罡湖底泥中铅的重要来源。④破罡湖底泥中镉含量达到极强生态危害影响水平,其他4种重金属潜在生态危害轻微,由于镉的贡献,导致破罡湖底泥多种重金属潜在生态危害总体上达到很强的水平。  相似文献   

12.
In order to estimate the present-day pollution levels in the ecosystem of the Selenga River Delta and to monitor the changes caused by the discharge of household refuse and industrial wastes,as well as the functioning of the agricultural and stock farming,a comprehensive study of the water and bottom sediments in the main branches of the Selenga River Delta was carried out.This study has determined the concentrations of heavy metals in river water and bottom sediments in its delta.  相似文献   

13.
In order to estimate the present-day pollution levels in the ecosystem of the Se-lenga River Delta and to monitor the changes caused by the discharge of household refuse and industrial wastes, as well as the functioning of the agricultural and stock farming, a comprehensive study of the water and bottom sediments in the main branches of the Selenga River Delta was carried out. This study has determined the concentrations of heavy metals in river water and bottom sediments in its delta.  相似文献   

14.
Paleolimnology provides long-term data that are often essential for understanding the current state of the environment. Even though there is great potential, paleolimnology is rarely used together with process-related studies to solve issues regarding cycling of elements in the environment. Clearly, this is a drawback because the cycling of many elements, which cause great concern in the present-day environment, was altered long before the advent of monitoring programs. The pioneering work of C.C. Patterson and his colleagues emphasized the importance of a long-term perspective for understanding the current cycling of metals, with a focus on lead, and in particular for estimating background concentrations and human-related impacts in the environment. In Sweden the first traces of atmospheric lead pollution are found in lake sediments dated to about 3500 years ago. The long-term changes in the pollution lead record in lake sediments led us to consider how lead biogeochemistry has changed over time in response to this historical deposition—where has this lead gone, and how much does this lead contribute to the present-day biogeochemical cycling of lead? How was lead distributed in ‘pre-industrial’ soils or more properly in natural soils not impacted by atmospheric pollution? There are many studies that have examined the effects of increased metal concentrations on soil biota, but what are the appropriate background conditions for comparison? Using lake sediments as our foundation we have analyzed lead, including its stable isotopes, in other environmental compartments, including peat, soil, and a range of boreal forest plant species, to develop a better understanding of the fate of lead derived from long-term pollution. Three important conclusions from our studies in Sweden are: (1) atmospheric lead deposition rates during the 20th century were 100 to as much as 1000 times higher than natural deposition rates a few thousand years ago. Even with stricter emission standards during the past three decades and the resultant reductions in deposition, lead deposition rates today are still 10–100 times greater than natural rates. This increase in deposition rates modeled from sediment and peat records is of a similar scale to estimated changes in body burdens of lead in modern versus ancient humans. (2) In Europe about half of the cumulative burden of atmospherically deposited lead was deposited before industrialization. In southern Sweden the cumulative burden of pollution lead during the past 3500 years is 2–5 g Pb m?2 and in the ‘pristine’ northern parts of the country there is about 1 g Pb m?2. (3) Predicted recovery rates for soils are slow; in the cold climate of Scandinavia, we find that the soil surface (O horizon), where most soil biota reside, retains lead deposited over the past 150–500 years. Therefore, although lead deposition rates in Europe, as well as N. America, are only 10% of those a few decades ago, it will take several decades or longer for lead concentrations in soils to respond appreciably. The slow turnover rates for lead in the environment and gradual immobilization of lead in deeper soil mineral horizons also inhibits a loss of lead to surface waters in areas removed from point sources.  相似文献   

15.
澜沧江河床沉积物重金属污染评价   总被引:2,自引:0,他引:2  
河床沉积物是河流水体与泥沙环境中重金属的主要积存载体,能反映水环境的重金属污染状况。本文选取澜沧江为对象,通过对澜沧江干流西藏和云南境内22个河段的河床沉积物重金属测定分析,得到了8种主要的重金属元素(Cr、Mn、Ni、Zn、As、Pb、Cu和Co)的含量,并采用沉积物富集系数法与地质积累指数法分别对所测得沉积物的重金属污染程度进行了评价。结果表明:①澜沧江干流大部分河段污染情况并不明显,但在中游的旧州和功果桥河段,因该区域的地质金属背景值和支流沘江流域铅锌矿开采,地表的重金属元素被雨水冲刷到该河段,导致沉积物重金属富集现象明显,出现了轻度到较强度污染;②澜沧江流域受人为干扰的区域集中于中游与下游,部分河段(功果桥附近)Cu、Pb和Zn等元素呈轻度或偏中度污染;③大坝对河流的阻隔效应使得干流沉积物重金属污染呈现片段化分布,河流沿岸城市化等人类活动对附近河段沉积物重金属污染状况也有较明显的影响。  相似文献   

16.
Sediment chemistry and arcellacean community composition were analyzed to study the ecological effects of copper mine-derived acidic and metal-rich waters in a freshwater bay in eastern Finland. To track spatial and temporal changes in the bay, 32 mine-impacted (top) and pre-impact (bottom) samples were analyzed from 16 short sediment cores taken along a transect extending from the pollution source. In addition, short cores from the impacted and reference sites were studied. Recent sediments displayed a geochemical gradient from the inner bay, where mine water is discharged, to the outer bay. Inner bay sites were enriched with C, S, and Fe, whereas Mn was depleted, but has precipitated in the outer bay. Among the heavy metals, Cu, Al, Zn, and Ni concentrations had increased in the inner and mid bay, while Co and Cd concentrations had increased at mid-bay sites. The change from the natural to mine-impacted condition was also seen in faunal gradients. According to ordination and distance measures, the greatest changes in species composition occurred in the inner bay, with fairly small changes in the outer bay. Numerical methods suggested that metals (Cu, Pb, Al, Zn, Cr), redox-sensitive elements (Fe, Mn), organic carbon and nutrients could be related to changes in arcellacean assemblages. Geochemical changes in the impacted core started at ~20 cm with increases in S alternating with peaks in Cr and Mg. Heavy metal concentrations increased markedly at 10 cm, after the active mining period, suggesting the beginning of acid mine drainage. Geochemical changes at ~20 cm were already apparent in the arcellacean assemblages, but the most notable change coincided with the geochemical shift at 10 cm, with signs of decreased pH. Numerical methods suggest that mining-related metals Co, Cu, Zn and Ni co-vary with arcellaceans, but Al appears to behave independently with respect to the species data.  相似文献   

17.
西溪湿地土壤重金属分布特征及其生态风险评价   总被引:11,自引:1,他引:11  
邵学新  吴明  蒋科毅 《湿地科学》2007,5(3):253-259
测试和研究了杭州西溪湿地土壤中铜(Cu)、锌(Zn)、铅(Pb)、镉(Cd)、汞(Hg)、砷(As)和铬(Cr)的含量与分布特征,采用内梅罗综合污染指数和Hakanson潜在生态危害指数法对湿地土壤重金属污染环境质量和潜在生态风险进行了评价。结果表明,西溪湿地土壤表层7种重金属平均含量的质量比分别为36.8 mg/kg(Cu)、91.5 mg/kg(Zn)、39.2 mg/kg(Pb)、0.23 mg/kg(Cd)、0.19 mg/kg(Hg)、6.3 mg/kg(As)和64.9 mg/kg(Cr)。由于受各种人为作用的影响,与浙江省土壤背景值相比,Cu、Pb、Cd和Zn在湿地土壤中的积累较大,有3个采样点[菜地、芦苇(Phram ites austrlis)滩地和靠马路的居民区]土壤中的Cd含量超过《土壤环境质量标准》(GB15618-1995)标准值的二级标准(pH<6.5)。湿地土壤重金属污染环境质量和生态风险评价结果显示,内梅罗综合污染指数平均值为1.73,多种重金属潜在生态风险指数平均值为114.6,说明总体上西溪湿地土壤重金属污染及其潜在生态风险为轻微级。最后,讨论了西溪湿地公园土壤重金属的可能来源,对比了重金属污染评价中不同评价标准和评价方法的差异性。  相似文献   

18.
以艾比湖东南部历史时期干涸湖底为研究区,对6种不同景观类型下富盐沉积物进行采样分析。运用经典统计研究了干涸湖底各景观类型下富盐沉积物盐分含量及盐分积聚特征。结果表明:不同景观类型的沉积物可溶性盐分含量差异显著。从平均值角度看,各景观类型表层沉积物中0~30 cm层的盐分含量占0~60 cm层盐分含量的70%,即沉积物盐分垂直分布呈强表聚性。各景观类型的沉积物盐分含量均属于中等变异强度(30%相似文献   

19.
沙丘形成演变是风-沉积物-其他地理因子相互反馈作用的一个动态系统过程,粒度可以揭示其中包含的部分环境信息并被广泛应用于风沙地貌研究。本文分析了巴丹吉林沙漠伊和吉格德湖高大沙山区沉积物粒度特征及其与植被、地貌形态的关系。结果表明:迎风坡中上部及中部剖面各层沉积物主粒径均一,分别为中沙、细沙;迎风坡中下部及底部剖面细沙、中沙及粗沙等不同主粒径层交替,粒配复杂,其成因与粗沙粒保护作用、风向季节变化及地质时期气候变迁等因素有关;背风坡表层沉积物以细沙为主,趋向底部粗沙、中沙及极细砂增多,说明不同粒径对风及重力作用的响应存在差异;粒度参数散点图可以区分不同部位样品,趋向迎风坡底部剖面,沙粒分选性变差,正偏、负偏及近对称沙层交替,说明风力分选作用在不同部位差异明显及存在其他外力作用;沙层粒配影响植被多样性,迎风坡中上部中沙含量高,背风坡表层中部偏上极细沙及大于2.65 Φ细沙含量突然增加,是植被影响粒配的反映;迎风坡沉积环境的差异,说明随地质时期气候变迁,沙山形成可能经历了两个重要阶段,一是早期风力和水动力交替影响、具有风成与非风成环境交替特征的基底形成时期,二是以风力作用为主的现代沙山形成时期。  相似文献   

20.
Physicochemical calculations of the abundance of a number of minerals and organo-mineral compounds in the river waters of the Ob basin revealed that the river waters throughout a year are able to actively interact with bottom sediments and river loads. The most active interactions occur in areas and during periods with increased moduli of river flow. It is shown that the increase in concentrations of dissolved organic matter in the river waters, including in the case of waste water discharges, is limited to a relatively low solubility of a number of compounds of metals with carbonates and humic acids.  相似文献   

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