羟基磷灰石吸附水溶液中Cd^2＋的影响因素的研究   总被引：14，自引：2，他引：14  

刘羽  胥焕岩  黄志良  罗惠华 《岩石矿物学杂志》2001,20(4):583-586

对羟基磷灰石(Hap)固定水溶性Cd2+的影响因素进行了较为系统的实验研究.实验表明去除率与Cd2+初始浓度呈负相关,在Cd2+初始浓度<10 mg/L时,与作用时间、pH值、Hap用量呈正相关,温度对去除率的影响较小.通过正交实验确定了最佳吸附条件Hap用量为5 g/L,pH值为6,作用时间5 min.  相似文献   

贵州都匀牛角塘富镉锌矿床中镉的分布及赋存状态探讨   总被引：9，自引：0，他引：9  

叶霖  刘铁庚 《矿物学报》2001,21(1):115-118

对贵州都匀牛角塘富镉锌矿的研究发现该矿床高度富集镉 ,矿石中镉含量一般为 2 2 84× 1 0 -6～ 9850× 1 0 -6,最高为 1 3 4 0 0× 1 0 -6,比地壳克拉克值 ( 0 .2× 1 0 -6)高 5～ 6个数量级 ,比工业品位高n× 1 0～n×1 0 2 倍 ,且其储量达到大型矿床的规模 ,在世界上十分罕见。镉主要以类质同象存在于闪锌矿中 ,少量镉以硫镉矿等独立矿物形式存在于矿床的氧化带 ,是风化淋滤过程中形成的镉的次生矿物。  相似文献   

无色散原子荧光法直接测定海水中的痕量镉   总被引：5，自引：1，他引：5  

周泳德  陈志兵  肖灵 《岩矿测试》2004,23(1):67-69

利用硫脲和Co2 对镉易挥发组分的形成有增强作用,建立了无色散原子荧光光谱直接测定海水中痕量镉的方法,检出限为0.044 μg/L,对镉含量为2.08 μg/L的样品进行11次测定,RSD为4.0%,线性范围为0～20 μg/L.对国家二级海水标准物质进行测定,结果与标准值相符.  相似文献   

成都盆地浅层土壤中Cd来源初探   总被引：6，自引：1，他引：6  

任利民  陈代庚  陈德友  唐文春  秦兵  周雪梅  马振东  胡以铿 《地质通报》2005,24(8):744-749

利用四川成都盆地多目标地球化学调查获取的大量数据，通过先线性回归再因子分析等多元统计分析方法，重点研究了浅层土壤Cd元素与其他元素的相关性及在空间上的分布规律，得出浅层土壤中Cd的回归方程及其由元素组合表征的2类来源：自然作用与人为作用。龙门山岩体、沉积地层和硫化物矿床是Cd的主要自然来源；农业活动和城市污染是Cd的人为源，表现为人为作用与自然作用的叠加这为生态评价和污染防治提供了重要参考。  相似文献   

β—Correction Spectrophotometric Determination of Cadmium with Cadion     

郜洪文 《中国地球化学学报》1995,14(1):93-96

Cadmium has been determined by β-correction spectrophotometry with cadion,p-nitrobenzenediazoaminoaz-obenzone,and a non-ionic surfactant,tuiton X-100.The real absorbance of a Cd-cadion chelate in the colored solution can be accurately determined and the complex-ratio of cadion with Cd(II) has been worked out to be 2.Beer‘s law is obeyed over the concentration range of 0-0.20mg/1 cadmium and the detec-tion limit for cadmium is only 0.003mg/1.Satisfactory experimental results are presented with respect to the determination of trace cadmium in wastewaters.  相似文献   

2,4—二硝基苯基重氮氨基偶氮苯测定矿石及煤矸石中痕量镉   总被引：5，自引：0，他引：5  

王磊  孙培培 《岩矿测试》1990,9(4):261-265

作者合成了新显色剂2,4-二硝基苯基重氮氨基偶氮苯,并研究了试剂性质及其与Cd(Ⅱ) 的显色反应。在Triton X-100存在下,于pH 11.8的Na_2B_4O_7-NaOH缓冲溶液中,显色剂与Cd形成2:1的红色络合物,λ_(max)为525nm,ε=1.68×10~5l·mol~(-1)·cm~(-1),Cd(Ⅱ)含量在0—6μg/25ml范围内遵守比耳定律。将该体系应用于萃取分离-光度法测定矿石及煤矸石样品的痕量镉,结果满意。  相似文献   

Accumulation of cadmium by bivalves in the Pacific Northwest     

Leah I. Bendell-Young 《中国地球化学学报》2006,25(B08):72-72

Bivalves （mussels, scallops, oysters）, from the Pacific Northwest coast of British Columbia, Canada, contain high levels of cadmium, in some cases exceeding 7 μg/g wet weight of tissue. We have for the past 5 years, attempted to determine the source of this cadmium to these filter-feeding invertebrates, with our objective being that we would then be able to advise where bivalves could be cultured for human consumption such that cadmium accumulation by the bivalve was minimized. Our studies have indicated that there are distinct regional and temporal variations in bivalve cadmium residues. Some patterns in cadmium accumulation did occur, e.g. for bivalves located on the most outer westcoast of British Columbia, cadmium residues demonstrated some seasonal dependence. In general, however, variations could not be readily ascribed to food sources （oceanic versus terrestrial）, or to abiotic factors such as salinity and turbidity. Cadmium residues in oysters were negatively correlated with temperature supportive of a seasonal influence on measured cadmium concentrations.  相似文献   

Heavy metal content in untreated forest soils in Southwest China     

Mahsa Haei Thorjom Larssen Grethe Wibetoe Hans M Seip 《中国地球化学学报》2006,25(B08):103-103

The rapid industrial development in China has caused a range of environmental problems. Along with emissions of ＂conventional＂ air pollutants, such as sulfur and nitrogen oxides, there are also increasing emissions of heavy metals to the atmosphere. Little information is available on metal contamination due to atmospheric deposition in forest soils in China. In order to get an overview of the extent of the problem, we conducted analyses of metal content in soil samples from three forested research catchments in Southwest China [Tieshanping （TSP） in Chongqing, Liuchongguan （LCG） and Leigongshan （LGS） in Guizhou]. Total concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, Sn and Zn were determined by Inductively Coupled Plasma-Mass Spectrometry after microwave digestion. The Hg content was determined using a Direct Mercury Analyzer. The concentrations of most of the analyzed metals were below the National Grade A standard limits in China for most samples, except for Cd and Pb where the limits were slightly exceeded at some of the sampling sites. In general, there were small differences between the different sites, although Cd and Co show a tendency to be higher at the most remote site （Leigongshan）. This site receives the lowest deposition of conventional air pollutants among the sites and the higher metals concentrations are possibly related to higher content in the soil parent material. There is no apparent general gradient in metal concentrations with proximity to cities, major air pollution emission sources, nor with sulphur deposition loads.  相似文献   

Enrichment and mobility of cadmium and other heavy metals in the area of the Three-Gorges Reservoir     

Jiang TANG Yong LI Jiali LEI Shijie WANG Tangfu XIAO 《中国地球化学学报》2006,25(B08):122-123

This study focused on the geochemical distribution patterns and ecological effects of Cd and other heavy metals such as As, Hg, Cr, Cu, Ni, Pb, and Zn in rock, soil, water, sediment and crops in the area of the Three-Gorges Reservoir within Chongqing, and aimed at the protection of ecological environment and rational application of the local lands. This study found that the metals of Cd, Hg and Pb presented pollution in the surface environment along the Yangtze River, that is Cd〉Hg〉Pb （Cu）〉Zn〉As〉Ni〉Cr. The pollution of Cd in sediment was mainly attributable to the regional black shales, and partly to the urban sewage and garbage. The geochemical modes of metals in the sediment varied. Cr, Hg, Ni, and Pb mainly existed as residues, and Cd as carbonate. Cd exited as a high proportion in the modes of ion-exchange, carbonate, and iron-manganese oxidation, up to 63 percent. The contents of heavy metals in soiland sediment were correlated to the host clay minerals, such as illite, montmorillonite, kaolinite and chlorite. It is shown that Cd was transported with clay minerals in the Yangtze River over long distance and formed the regional anomaly. In the abnormal area of Jianping in Wushan County, higher Cd contents are reported in the local crops and local villagers＇ hairs than from the background areas.  相似文献   

Assessment of cadmium contamination in the sediments of Changjiang （Yangtze） River by reflectance spectroscopy     

Farid Moore Fatemeh Rastmanesh 《中国地球化学学报》2006,25(B08):226-226

The Takab area in NW of Iran is an important gold mineralized region with a long history of gold mining. In this study ASTER data is used to evaluate environmental effects of gold mining. The results show that mining activities have resulted in release of potentially toxic metals （PTMs） in the area. Principal component analysis （PCA） of ASTER data is used to map sources of PTMs and their secondary hosts （iron oxides） through alteration mapping. The results show that selective PCA is a robust yet time consuming technique for alteration mapping. A color composite is created for finding common hydrothermally altered rocks. The created color composite successfully mapped the known deposits and anomalous areas identified by geological survey of Iran. Because of the low spatial resolution of ASTER sensor, the iron oxide mapping is restricted to the wider portions of the streams. Spectral analyses confirm the presence of hematite and goethite in stream sediments. This is in accordance with measured pH values.  相似文献