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1.
Seventy-five samples of six soil profiles from forests on different substrates plus one next to a motorway were analyzed for the variation of Pb concentration and isotopic composition with depth. A substantial fraction of the anthropogenic Pb (peak concentrations between 74 and 300 ppm) is still stored in the organic top soil, and seldom penetrates deeper than 20–30 cm. In (208Pb/206Pb) vs. (207Pb/206Pb)-diagrams the Pb in the uppermost layers of the profiles plots on an excellent correlation line (R = 0.99) indicating essentially a two-component mixing system. Values for the dust on Scottish plants, Norwegian and Swiss bogs as well as for aerosols collected over the North Atlantic (data from the literature) plot on the same correlation line showing that the Pb was deposited from a continent-wide mixing system with two apparent end members: The radiogenic one is similar to geogenic Pb and could consist of contributions from certain European ore deposits and from different soil components (e.g. silicates and Fe-oxides), power plants and cement factories. The less radiogenic component must contain or consist of Pb from Proterozoic or even Archaic ore deposits. However, the sources of this Pb remain somewhat elusive. In any case, this isotopic pattern is so consistent all over Europe that the correlation line may serve as a line of reference for quasi normal or European Standard Lead Pollution (ESLP). The gasoline derived Pb in the soils is swamped by Pb of other provenances.  相似文献   

2.
The properties of stable oxygen isotopes make them useful for studying processes involved in the atmospheric oxidation of sulphur compounds. Experimental work in the 1980s reported that the formation of primary combustion sulphates by high temperature oxidation of SO2(g) to SO4 leads to δ18OSO4 values between +40 and +45‰. This study reports sulphate oxygen isotopic compositions from precipitation events collected at two sites in eastern Newfoundland. Values as high as +41.7‰ were measured in natural precipitation samples collected near a small oil-fired power plant located on the campus of Memorial University of Newfoundland in St. John's. These values are higher by 16‰ than any previously reported for precipitation in the literature and in conjunction with other chemical data implicate the power plant as the pollution source. Values from the second site (Seal Cove) were similar to previously reported ranges for precipitation, despite its proximity to a much larger oil-fired, thermal generating station, suggesting that different oxidation mechanisms were dominant there. Oxygen isotopic compositions of precipitation sulphates can be an important complementary tool to other isotopic, trace metal and meteorological analysis in the tracing of sources of atmospheric sulphur compounds.  相似文献   

3.
窟野河流域不同水体同位素及水化学特征分析   总被引:2,自引:0,他引:2  
通过野外调查取样和室内测试分析,应用水化学和同位素技术,分析了窟野河流域不同水体的水化学和氢氧同位素特征,探讨了不同水体的关系。结果表明:(1)河水的水化学类型由上游的Na~+-Ca~(2+)-HCO_3~--SO_4~(2-)演变为下游的Na~+-Ca~(2+)-SO_4~(2-)-HCO_3~-。上游矿井水水化学类型与上游河水一致;上游矿区生活用水距离河道1 000m以内,井深180m的水样点,水化学类型与河水一致;距离河道1 000m,井深180m的水样点,水化学类型与河水有一定的差距。下游灌溉用水水化学类型为Ca~(2+)-Na~+-SO_4~(2-)-HCO_3~-,与河水一致。(2)流域大气降水线斜率和截距都小于全球大气降水线和中国大气降水线,表现出氢氧同位素大陆效应的影响。从上游向下游,河水的氢氧同位素组成有逐渐富集的趋势。上游乌兰木伦河矿井水氢氧同位素与河水氢氧同位素组成相近,说明河水与矿井水水力联系密切。生活用水由于取样井深的不同和距离河道远近的不同导致各样点氢氧同位素含量具有一定的差距。下游灌溉用水的氢氧同位素组成与河水相似。  相似文献   

4.
Eurasian Soil Science - Isotopic composition of nitrogen in soils can be an informative indicator of N transformation processes and sources of N nutrition of plants, but data on δ15N of labile...  相似文献   

5.
王刘炜  程敏  邓渠成  侯仁杰  侯德义 《土壤》2022,54(5):1032-1040
本文以我国西南某矿区典型多金属复合污染农田土壤为例,基于铅(Pb)稳定同位素分析,结合矿物学分析,对土壤Pb来源进行定量解析,并针对其他重金属来源进行外推。同位素源解析结果表明,人为源对于土壤重金属的贡献率高达61%~89%,矿渣浸沥与矿区道路扬尘为主要的污染途径。矿物学分析能够辅助印证Pb稳定同位素分析结果,在一定程度上克服由于污染源信号重叠造成的源解析困难。通过相关分析,可以将Pb同位素源解析的结果合理外推,在一定程度上解释其他重金属元素的来源。本文提出的源解析新思路能够高效、准确地解析多金属复合污染土壤中重金属元素的来源,尤其适用于我国土壤多金属复合污染集中连片存在、成因复杂的现状,具有很强的现实意义。  相似文献   

6.
Eurasian Soil Science - Carbon isotope ratios in soil organic matter are often used in paleoecological research for reconstructing climate and plant communities (type of photosynthesis). The...  相似文献   

7.
In this biological oxygen demand (BOD) study, the manometric respirometric BOD OxiTop® method was used to monitor the biodegradation of two summer grade (SFO 1 and 2) and two winter grade light fuel oils (WFO 1 and 2) in OECD 301 F conditions, in groundwater, and in two different Finnish forest soils (mineral-poor and mineral-rich). The biodegradation measurements in the OECD 301 F conditions were carried out in two nutrient solutions for 28 days. In both solutions WFO 1 reached the highest biodegradation degree, 32% in the solution OECD 301 F, and 70% in a solution containing additional ammonium chloride. In groundwater conditions all the biodegradation degrees of fuel oils remained below 2% within the 28-day period. SFO 1 reached the highest 30 day biodegradability (4%) in mineral-poor soil, 18% in mineral-rich soil. In a 189-day measurement in a mineral-rich soil, the biodegradation degree for the SFO 1 was 94%. The manometric respirometric method proved to be a very suitable and practicable measurement method for the purpose of biodegradation studies of highly volatile light fuel oils, because in this method samples are treated to a lesser degree than in conventional methods, and dilutions are not needed. Results also indicated a considerable effect of conditions on the biodegradability in both water and soil environments. The results of these biodegradation studies could be used when planning in situ treatment methods based on natural biodegradation. In situ treatment methods are eco-efficient, and are especially suitable for sparsely populated sites.  相似文献   

8.
黑麦草对土壤中Pb的富积作用及耐受性研究   总被引:3,自引:0,他引:3  
通过土培实验研究了在单一因素影响下,不同浓度的Pb对黑麦草种子萌发及幼苗生长的影响,同时测定了其抗性生理指标的改变以及地上部分和根系对Pb的富集作用.实验结果表明,低浓度的Pb(<500 mg/kg)单一污染时,对黑麦草种子萌发及幼苗生长有促进作用.高浓度时有显著的抑制作用.且随着浓度的升高(500~2 000 mg/kg),抑制作用和毒害作用都加强,各项指标均出现显著降低.同时,随Pb浓度增加,丙二醛(MDA)和可溶性糖含量显著增加,呈极显著正相关.叶片光合色素含量先增后减,呈负相关.黑麦草对Pb有一定的富集能力,当Pb浓度为500 mg/kg时,地上部分相对累计量达到最大.  相似文献   

9.
Water, Air, &; Soil Pollution - A hybrid chemical kinetic and equilibrium model has been developed to quantitatively assess the dynamic oxidation-reduction (redox) transformations of chromium in...  相似文献   

10.
The chemical composition of surface water in the Central Forest State Natural Biospheric Reserve is characterized by well-pronounced seasonal dynamics related to the intensity of biological turnover. Three groups of chemical elements with different types of seasonal dynamics are specified. The impact of soils on the chemical composition of surface water is most pronounced in the summer, when concentrations of dissolved organic carbon and microelements are the highest and correlate with one another. The groundwater is the main source of calcium, sodium, and magnesium for the local Mezha River. Aluminum and water-soluble organic substances are supplied with soil solutions from organic horizons (10–50 cm). Iron and manganese are discharged into the river both with surface soil waters and with the groundwater flow. The migration of aluminum in the Mezha River basin is mainly controlled by the pH conditions, whereas the migration of iron depends on the concentration of dissolved organic carbon.  相似文献   

11.
The study was performed on the area of the three countries involved in the MAGPROX project (Poland, Czech Rep., Germany). In the first stage the basic map of magnetic susceptibility based on the field topsoil measurement was compiled with an average grid density of 10 km. In the second stage of the study, vertical distribution of magnetic susceptibility of ca. 600 topsoil cores (0.3 m long), collected over central Europe, was examined with respect to the anthropogenic or lithogenic influence on magnetic susceptibility of the soil surface, with the focus being on the interpretation of the areas showing high surface susceptibility values. The maximum values were mostly observed in depths of 3–4 cm. In general seven different types of susceptibility profiles from forest areas and one typical for urban soil are presented. They are a result of a combination of natural (litho- and pedogenic) and anthropogenic contributions. Our results prove that soil profiles, dominated by anthropogenic influence due to atmospherically deposited dust, are characterized by magnetically enhanced humuous layer, corresponding to layer with the highest concentration of heavy metals. Moreover, forest soils show in these cases higher magnetic susceptibility than soils in open areas (grassland, meadows or arable soils).  相似文献   

12.
Water-particle interactions often may result in non-conservative chemical behavior when waters from different sources mix with one another. The results presented in this paper address the role of these interactions in freshwater and estuarine mixing and support a larger study to develop a method to help resolve flow distribution and water quality questions in surface waters using a source water “fingerprinting” technique. Inductively coupled plasma-mass spectrometry (ICP-MS) is used to “fingerprint” each water source based upon the concentrations and relative proportions of elements in that source. Estimates can then be made of the fractions of various “fingerprinted” waters in water samples that contain a mixture of source waters. Such estimates depend upon the selection of tracers that behave conservatively during mixing; in this paper, results to establish the maximum particle exchange capacity and conservative mixing behavior are presented for samples collected from the Sacramento River-San Francisco Bay-Delta estuary. Elements likely to behave conservatively include boron, sodium, magnesium, potassium, calcium, strontium, and molybdenum.  相似文献   

13.
The following measurements were carried out to clarify acid deposition in Niigata Prefecture, an area facing to the Sea of Japan. 1) Acid deposition fluxes and sulfur isotopic ratios of atmospheric deposition were measured at 9 sites in the prefecture in 1999. 2) Atmospheric deposition was collected daily at one site in 1997, to measure the sulfur isotopic variations of sulfate together with the air mass trajectory for each deposition. It became clear that: (a) The major component that acidifies atmospheric deposition is sulfuric acid. (b) Sulfate deposition increases in winter in the whole study area. (c) The sulfur isotopic ratios indicate that sulfur dioxide emitted from China affects the whole study area in winter. (d) Winter deposition of sulfate estimated to derive from coal combustion in China account for half of nss-sulfate deposition in average at 9 sites.  相似文献   

14.
Eurasian Soil Science - The results of studying stable carbon isotopes of the organic matter of Late Pleistocene and Holocene soils of the Baikal region are presented. The δ13С values in...  相似文献   

15.
土壤界限含水量作为重要的土壤力学指标,直接影响着坡耕地土壤抗冲性和土壤侵蚀过程。土壤机械组成与界限含水量特征值存在因果关系;研究两者间关系,有助于阐明坡耕地土壤侵蚀机理。以黔中3种主要岩性区坡耕地为研究对象,用野外调查及室内试验的方法,探讨了土壤机械组成对界限含水量的影响。结果表明:3种母岩区坡耕地土壤塑限为石灰岩区(30.49%)>紫色砂岩区(24.12%)、砂页岩区(20.50%),土壤液限为石灰岩区(56.30%)>紫色砂岩区(43.09%)>砂页岩区(32.80%),塑性指数为石灰岩区(26.03%)>紫色砂岩区(18.97%)>砂页岩区(12.29%)。石灰岩区坡耕地土壤粗砂含量、粉粒含量与液限、塑性指数呈负相关,黏粒含量与液限、塑性指数呈正相关;紫色砂岩区坡耕地粗砂含量与液限、塑性指数呈显著负相关,粉粒含量、黏粒含量与液限、塑性指数呈显著正相关;砂页岩区坡耕地粗砂含量与液限、塑性指数呈显著负相关,黏粒含量与液限、塑性指数呈显著正相关。不同岩性分布区坡耕地的界限含水量存在差异,成土母岩的差异是造成3种坡耕地土壤界限含水量差主要原因。  相似文献   

16.
Eurasian Soil Science - Research data on the isotopic composition of carbon in soil lipids in the Zhirnovskoe and Bakhmet’evskoe oil and gas fields in the Medveditsa River basin, Volgograd...  相似文献   

17.
水环境中有机磷农药生物标志物的研究进展   总被引:1,自引:0,他引:1  
有机磷农药(OPs)的大量施用导致水环境的污染,影响到非靶生物特别是鱼类的生存。因此,需要对OPs进行快速、灵敏、准确监测,以便及时采取必要的措施。近二十年来,国内外学者在利用生物标志物监测水体OPs方面进行了大量研究。本文对这些生物标志物的分布、结构、特点及其对OPs的响应特征进行了综述,并提出了生物标志物监测水体OPs存在的问题及进一步研究的方向。  相似文献   

18.
青海省境内黄河上游区水沙来源及组成分析   总被引:10,自引:2,他引:10  
青海境内黄河上游地区是青海省工、农、牧、渔业生产基地,也是国家列入重点开发的水电基地之一,在青海省经济发展中占有举足轻重的地位。近年来,随着黄河下游断流的日益严重,作为黄河水量主要供给地的青海境内生态环境保护已成为全社会关注的焦点。利用青海境内黄河上游主要水文测站的资料,对境内水沙来源及组成进行了分析,认为该区面积只占黄河流域面积的23.4%,而径流量占47.5%,输沙量只占3.86%,是黄河的主  相似文献   

19.
20.
本文通过对宝鸡峡灌区波涌灌和连续灌前后大量土壤取样的粒度组成分析认为,灌水对农田土壤粒度组成的时空分布的影响是长期效应。波流灌灌水技术参数,除入沟、畦流量外,放、停水时间及循环率对土壤的粒度组成没有明显的影响。灌水过程中入渗携带的极少细颗粒并不是波涌灌表层土壤导水率降低的原因。  相似文献   

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