长江三峡库区土壤与水系沉积物Cd地球化学特征   总被引：11，自引：0，他引：11  

唐将  刘安云  邓富银  雷家立 《地质通报》2005,24(8):750-754

对长江三峡库区段不同介质中Cd的分布特征和长江水系沉积物在垂向、横向剖面上的元素分布特征的研究发现，残坡积型土壤与长江干流水系沉积物Cd含量差异较大，水系沉积物具明显的高Cd异常；各个沉积时期的水系沉积物中均存在Cd异常，上游来源的Cd是引起三峡库区水系沉积物高Cd异常的主要因素；人类活动对土壤和水系沉积物中Cd的含量影响明显，在厂矿、码头、生活垃圾场等地区土壤中Cd的含量远高于一般地区土壤中Cd的含量，城市排污水系沉积物Cd的含量也高于长江干流水系沉积物Cd的含量。自然源是沿长江流域Cd异常普遍存在的根本原因，而人为源却有可能是高Cd异常主要沿长江干流及支流两岸大中城市分布的重要影响因素。  相似文献   

Trends in atmospheric Cd deposition recorded in a 64-meter long ice-core and a 5-m snow pit record from Devon Island, Nunavut, Canada     

Yaping WANG Chunxue XU Suming WANG Ziyi AN 《中国地球化学学报》2006,25(B08):15-15

Along with the rapid development of science and technology, natural matter and energy are further exploited and used. The pollution imposed on nature has also sharply increased. Only do we know the pollution history, can we make a correct appraisal of local environment, get the hold of the main cause of environmental pollution, and then take the effective measures to control the environment？ The evolution of heavy metal concentrations with time in the soil environment in the southern suburbs of Beijing were studied by using annual growth rings of trees. The absorption of 12 elements by different tree species in the same soil type was studied according to their absorption coefficients. The study indicated the differences in adsorption of elements by different species of trees. The adsorption coefficients of the elements Zn, Cd and P are higher. The correlations of nine elements （Na, K, Cu, Zn, As, Sr, Cd, Ba and Pb） in growth rings of poplar trees and those in soils near their roots show that the element contents in growth rings have a positive correlation with the contents in soils near the roots. Based on the logarithmic linear correlation model, the evolution of the contents of the elements Cu, Zn, As, Cd, Ba and Pb in soils from 1982 to 2004 was deduced. The trees have the characters of confirming year precisely, long life and widespread distribution. They are the ideal objects of study on environmental pollution changes. At present, research in China in this aspect is less, and the field of research is expected to further expand. This method can be used to provide richer and more scientific information on the history of environmental pollution and changes during modem urbanization in the past few decades and predicting the evolutionary trend of pollution change.  相似文献   

Pore water trace metal chemistry in polluted sediments of a tropical estuary of SE Brazil     

Sambasiva Rao Patchineelam Edouard Metzger Didier J uel Gerard Sarazin 《中国地球化学学报》2006,25(B08):66-67

The Sepetiba Bay is a shallow water body semi enclosed located on the west side of Rio de Janeiro City. Almost 80% of flesh water discharge, from the St Francisco canal, coming from the northern side of the bay develops an estuarine environment. Fishing and tourism are some of the most important economic activities in the area. During 35 years a zinc/cadmium smelter has polluted the bay. The objective of this investigation is to demonstrate the diagenetic processes and cadmium remobilization into pore water from the contaminated sediments. Two sites were selected to compare diagenetic processes. Site P1 is located next to domestic effluents discharge into the bay and approximately 20km away from the smelter. Site P2 is located near the same smelter and next to the Mazomba estuary, which is not influenced directly by domestic effluents. Peeper samplers of 25 cells with a resolution of 2.5 cm were deployed at both the sites. After a 3-weeks period of equilibrium, the pore waters were separated from the cells and analyzed immediately （within 24 h） for alkalinity, NH3 and reactive soluble phosphorus on a spectrophotometer. An ICP-AESΣH2S spectrometer was used to analyze Na, Mg, Li, Ba, Sr, Si, Fe and Mn. Total and labile dissolved Cd in pore waters were determined by differential-pulse stripping voltametry. The dissolved constituents in the pore waters have shown that the intensities of diagenetic reactions are different between sites. The reactions are stronger at site P1 site than at site P2, especially between 7.5 cm and 22.5 cm, which is evident by the organic rich sediment.  相似文献   

断续流动在线分离富集-蒸气发生原子荧光光谱法测定复杂环境样品中痕量镉     

李中玺  周丽萍 《岩矿测试》2006,25(3):233-238

用D201阴离子交换树脂富集样品中的痕量Cd，使Cd与共存干扰元素Cu、Ni、Pb、Zn有效分离，消除了这些元素对镉蒸气发生的干扰，从而建立了断续流动在线分离富集-蒸气发生原子荧光光谱法测定复杂环境样品中痕量Cd的分析方法。方法的检出限为3ng／L（3σ）；测定精密度（RSD）为1．9％（对1μg/L Cd，n=11）。用该方法对国家一级标准物质（土壤、水系沉积物和岩石）中的痕量镉进行了测定，结果与标准值相符。  相似文献   

地衣芽孢杆菌(Bacillus licheniformis)对镉胁迫下泥蚶(Tegillarca granosa)的抗氧化酶活性和免疫相关基因表达的影响     

王稷  李晔  瞿洋  沈灵灵  孙静  全晶晶 《海洋与湖沼》2014,45(5):1058-1063

本文研究一株地衣芽孢杆菌(Bacillus licheniformis)对提高泥蚶耐受镉(Cd2+)胁迫的作用,实验分析了不同浓度地衣芽孢杆菌对Cd2+胁迫下泥蚶(Tegillarca granosa)的存活率及组织中Cd残留量的影响;同时比较了地衣芽孢杆菌作用前后,泥蚶体内两类抗氧化酶,超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)的活性,进一步通过Real-time PCR分析了三类免疫相关基因金属硫蛋白(MT)、小热休克蛋白分子(sHSP)和铁蛋白(ferritin)的表达情况。研究结果显示,地衣芽孢杆菌能降低泥蚶组织中Cd残留量,提高其存活率。并能有效促进泥蚶体内SOD和GSH-Px酶活性的增加,同时降低MT、sHSP和ferritin在mRNA水平上的表达。数据表明该地衣芽胞杆菌可通过调节泥蚶的免疫系统,起到降低Cd2+对泥蚶毒害的作用。  相似文献   

广西象州与横县碳酸盐岩分布区土壤中Cd形态分布特征及影响因素   总被引：2，自引：0，他引：2  

刘旭  顾秋蓓  杨琼  余涛  张起钻 《现代地质》2017,31(2):374

广西壮族自治区碳酸盐岩分布面积为96 372 km2,约占全区陆地国土面积的407%。由碳酸盐岩风化形成的土壤中Cd、Pb、Hg等重金属元素普遍富集。初步评价发现,农作物籽实对Cd的吸收量与土壤Cd含量无对应关系,农作物Cd超标多出现在土壤Cd含量较低的地区。进一步研究发现,Cd高含量的土壤中普遍含有铝土矿、Fe Mn结核等颗粒。为了探索土壤中Cd存在形态及其影响因素,选择了含铝土矿和铁锰结核的横县土壤和无铝土矿与铁锰结核的象州土壤,系统研究了土壤Cd形态差异及其影响因素。结果表明：(1)象州土壤中Cd主要以活动态形式存在,生物可利用性高,横县土壤中Cd主要以稳定态形式存在,生物可利用性低。(2)pH值为60是象州土壤Cd活动态含量的突变点,pH值在60处含量达到最大值;而在横县,pH降低使活动态Cd比例增加。(3)象州土壤中活动态Cd随有机质增加而增加,表明Cd被有机质弱吸附;而横县土壤有机质含量与Cd形态无明显相关性。(4)由铝土矿导致的土壤高Cd含量,多以残渣态形式存在,不会对动植物造成危害。  相似文献   

膜去溶-电感耦合等离子体质谱法测定环境地质样品中的镉   总被引：3，自引：3，他引：0  

王岚  杨丽芳  谭西早  武朝辉 《岩矿测试》2017,36(6):574-580

应用电感耦合等离子体质谱法(ICP-MS)分析环境地质样品中的Cd时,Zr、Mo元素的氧化物和氢氧化物会对Cd造成严重干扰,导致结果有明显的偏差。针对此问题,本文建立了膜去溶-ICP-MS直接测定环境地质样品中微量Cd的分析方法,该方法可有效地消除Zr、Mo氧化物和氢氧化物对Cd的干扰,保证结果准确、可靠。膜去溶-ICP-MS相比于常规ICP-MS测定Cd的方法,可将Zr、Mo氧化物和氢氧化物对Cd的干扰降低到0.001%,检测灵敏度提高3.5倍左右。在给定条件下,Cd的检出限为0.28 ng/L,测定下限为2.2 ng/L,精密度(RSD,n=12)为2.2%。利用该方法分析20种岩石、土壤和沉积物国家标准物质的测定值与标准值相符,表明膜去溶-ICP-MS法直接测定环境地质样品中痕量或超痕量Cd时具有一定的应用潜力。同时,用该方法对2016年中核集团组织的实验室间两个比对样品中的Cd进行测定,稳健Z比分数分别为0.500和-0.964,Z的绝对值都小于2。  相似文献   

Biochemical and Physiological Responses in Atlantic Salmon (Salmo salar) Following Dietary Exposure to Copper and Cadmium     

A. -K. Lundebye  M. H. G. Berntssen  S. E. Wendelaar Bonga  A. Maage 《Marine pollution bulletin》1999,39(1-12):137-144

Three experiments were conducted with Atlantic salmon (Salmo salar) to assess the effects of dietary exposure to copper and cadmium. The results presented here provide an overview, details of each experiment will be published in full elsewhere. In the first experiment, salmon parr exposed for four weeks to 35 and 700 mg Cu kg⁻¹ diet had significantly elevated intestinal copper concentrations, cell proliferation (PCNA) and apoptosis rates compared to control fish. No differences were observed in gill or plasma copper concentrations among the groups. In contrast to the controls, the Cu exposed groups did not grow significantly during the exposure period. The second experiment (three months exposure) was conducted to assess the effects of dietary copper (control, 35, 500, 700, 900 or 1750 mg Cu kg⁻¹ diet) on growth and feed utilization in salmon fingerlings. Growth was significantly reduced after three months exposure to dietary Cu concentrations above 500 mg kg⁻¹. Similarly, copper body burdens were significantly higher in fish exposed to elevated dietary copper concentrations (above 35 mg Cu kg⁻¹ diet). In the third experiment, salmon parr were exposed to one of six dietary cadmium concentrations (0, 0.5, 5, 25, 125 or 250 mg Cd kg⁻¹ diet) for four months. Cadmium accumulated in the liver>intestine>gills of exposed fish. Rates of apoptosis and cell proliferation in the intestine increased following exposure to dietary cadmium. Exposure to elevated concentrations of dietary cadmium had no effect on growth in salmon parr. Results from these studies indicate that cellular biomarkers have potential as early warning signs of negative effects on the overall fitness of an organism.  相似文献   

外源鸟氨酸对菹草(Potamogeton crispus L.)抗镉胁迫能力的影响     

夏海威  吴娟  黄敏  施国新  乔绪强  陈霖  姜岩  汪鹏合 《湖泊科学》2014,26(2):288-296

本文以组织培养技术培养的菹草无菌苗为实验材料,研究了2 mmol/L外源鸟氨酸(L-Orn)对40μmol/L镉(Cd)胁迫下菹草体内Cd含量、光合色素水平、超氧阴离子(O·-2)产生速率、过氧化氢(H2O2)、丙二醛(MDA)与可溶性蛋白含量以及脯氨酸和多胺代谢的影响.结果显示:(1)在单一Cd胁迫下,菹草体内的Cd大量积累,达到335.00μg/g,并诱导了明显的氧化胁迫,具体表现为O·-2产生速率以及H2O2和MDA含量显著升高,可溶性蛋白以及光合色素含量明显下降.外源L-Orn的添加很大程度上抑制了菹草体内Cd的积累,Cd含量降至232.50μg/g,并降低了活性氧(ROS)水平,减轻了膜脂过氧化程度,减缓了光合色素和可溶性蛋白的分解.(2)在单一Cd胁迫下,伴随着吡咯啉-5-羧酸合成酶(P5CS)活性的增加和脯氨酸脱氢酶(ProDH)活性的下降,菹草体内的脯氨酸含量轻微增加,仅为对照组的1.91倍,而外源L-Orn显著增强了P5CS和δ-鸟氨酸转氨酶(OAT)的活性,使脯氨酸含量大幅度升高,为对照组的8.36倍.(3)单一Cd胁迫分别通过激活精氨酸脱羧酶(ADC)、鸟氨酸脱羧酶(ODC)和多胺氧化酶(PAO)的活性,使腐胺(Put)的含量增加,亚精胺(Spd)和精胺(Spm)含量减少.而施用外源L-Orn后,ADC和ODC的活性进一步增强,Put的含量大幅增加,并促进Put向Spd和Spm的转化,同时PAO的活性下降,使Spd和Spm含量增加,从而使总多胺含量增加.由此可见,外施L-Orn可通过抑制Cd的进入和参与调节脯氨酸以及多胺代谢,抑制ROS的积累、膜脂过氧化、光合色素以及蛋白质的分解,一定程度上增强菹草对Cd胁迫的抗性.  相似文献   

Adsorption of cadmium on riverine sediments: quantitative treatment of the large particles     

C. K. Jain  I. Ali 《水文研究》2000,14(2):261-270

The effects of solution pH, sediment dose, contact time, and particle size on the adsorption of cadmium ions on bed sediments have been studied for a highly polluted river in western Uttar Pradesh, India. The role of the coarser sediment and the clay and silt fractions has been examined. The optimum contact time needed to reach equilibrium is of the order of 30 and 60 min for 0–75 μm and 210–250 μm sediment size, respectively. The extent of cadmium adsorption increases with increasing pH and adsorbent doses and decreases with adsorbent particle size. The important geochemical phases, iron and manganese oxide, provide the active support material for the adsorption of cadmium. The competitive experiments conducted in the presence of lead and zinc ions indicate that both the ions suppress the ability of cadmium to adsorb on to sediments. The Langmuir and Freundlich adsorption models were used to determine the mechanistic parameters associated with the adsorption process. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献