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11.
Recent evaluations of acute and chronical toxicity of arsenic resulted in a reduction of the standard value for total arsenic from 40 μg/L to 10 μg/L in drinking water which will be valid in Germany after a transition period as from January 1996. Arsenic is well known as substance of deep groundwaters, mainly of geogenic origin and normally found as As(III) or As(V). As(V) is well removable by flocculation and filtration after adding iron salts. As(III), however, has to be oxidized first to As(V). Therefore, it is important for treatment techniques to be able to distinguish between As(III) and As(V). A modified determination of As(III) using flow injection analysis was installed and optimized in order to investigate whether As(III) may be oxidized to As(V) by bacteria in natural waters. The results showed that at 4°C, no As(III)-oxidation was observed within 14 days. At room temperature, however, in the bacteria-containing samples, an As(III)-oxidation was found starting after 3 to 7 days. After 14 days, no As(III) was left over. In contrast, in the sterile samples, no As(III)-oxidation could be observed within 14 days. These results demonstrated that microbial processes influence the oxidation of As(III) to As(V) in natural waters. 相似文献
12.
原子荧光光谱法测定化探样品时有机质对As,Sb,Bi的干扰 总被引:1,自引:0,他引:1
通过研究黑龙江省森林沼泽景观区有机水系沉积物(泥炭)、土壤中As,Sb,Bi的测定结果,发现样品中的有机质对王水消解氢化物原子荧光法测定上述元素存在极大的干扰,提出采用低温(<450℃)灰化处理可完全消除干扰。对比研究还发现,过去森林沼泽景观区的区域化探扫面资料中的As,Sb,Bi数据存在问题,应专门对其进行评价研究。 相似文献
13.
14.
Hg、As、Sb是土壤和河流沉积物的常规测定项目。本文采用新型三通道原子荧光分析仪,建立了同时测定土壤和河流沉积物中这三种元素的新方法。通过优化仪器工作条件,选择合适的样品处置方法,得到Hg、As、Sb的检出限分别为0.03mg/kg、0.009mg/kg和0.03mg/kg,精密度分别为3.5%、7.8%和5.5%,准确度分别为95%~103%、91%~107%(加标回收率)和±6.4%。与现有测定方法相比,本方法的样品消化完全,实验简便,分析速度和准确度高,能充分满足分析要求。 相似文献
15.
16.
Adivane Terezinha Costa Hermínio Arias Nalini Paulo de Tarso Amorim Castro Jorge Carvalho de Lena Peter Morgenstern Kurt Friese 《洁净——土壤、空气、水》2006,34(3):245-256
This paper describes the geochemistry of sediment samples placed in floodplains and alluvial terraces downstream from gold mines in the Carmo River basin, Quadrilátero Ferrífero, Minas Gerais, Brazil. The geochemistry signature Na2O, K2O, SiO2, CaO, MgO, Al2O3, Fe2O3, TiO2, P2O5, Mn, As, Cu, Zn, Ba, Ni, Cr, S, Co were analyzed in different facies from stratigraphic profiles. As, Cu, Zn, and Mn anomalies are mainly associated with the clayed facies deposited in floodplains and oxbow lakes, and with coarse‐sediment facies deposited in the channel. The facies were accumulated by the gold exploitation activity in the region. The contamination of As, Cu, and Zn was controlled by minerals such as iron oxides and hydroxides (hematite, magnetite, and mainly goethite), manganese oxides, and sulfide‐rich minerals. The As‐bearing sediments of the region characterize one of the most As contaminated area of Brazil. Their main source is associated with gold exploration in the last three centuries. 相似文献
17.
武山铜矿北矿带ICu矿体砷的分布规律 总被引:1,自引:0,他引:1
武山铜矿化矿带ICu矿体是高砷矿体,分析了砷在各金属矿物中含量及分配情况和含砷量的分布规律,确定了高砷采场或矿段,指出了进行矿石质量控制,配矿管理的降砷途径。 相似文献
18.
原子荧光光谱法直接连续测定化探样品中的As Sb Bi Hg 总被引:7,自引:1,他引:6
研究了还原性介质中原子荧光光谱法直接连续测定化探样品中As、Sb、Bi、Hg的方法。按拟定的条件进行测定,各元素的检出限分别为As2.9×10-9、Sb1.3×10-10、Bi1.8×10-10、Hg5×10-11。应用于区域化探扫面工作中,效果良好。 相似文献
19.
YU Yunmei ZHU Yongxuan & GAO Zhenmin Key Laboratory of Ore Deposit Geochemistry Chinese Academy of Sciences Guiyang China 《中国科学D辑(英文版)》2004,47(5)
Arsenopyrite is one of the most important pri-mary arsenic mineral. In the Eh-pH diagram of the As-O2-S-H2O system, if the total arsenic concentration (TAs) is taken to be 0.75 mg/L, the total sulfur con-centration, 32 mg/L, the temperature, 25℃and the pressure, one atmosphere pressure for the discrimina-tion of arsenic species, it may be found that under hy-pergene conditions, arsenopyrite is a moderately stable mineral. Only in the strongly alkaline and reducing environment can arsenopy… 相似文献
20.
The Lanmuchang Tl deposit and its environmental geochemistry 总被引:8,自引:1,他引:7
Tl is a dispersed element and it seldom occurs in the form of independent minerals.The world annual production of Tl is about
13 ton, most of which is by-product separated from non-ferrous metal products. Lanmuchang is the only large-size independent
Tl deposit in the world. Bio-enrichment and hydrothermal reworking are the two important metallogenic mechanisms of this Tl
deposit. Samples of plant and animal organs and villagers’ urine as well as hair and nail (toenail) samples from the Tl mining
district were analyzed. Analytical results showed that the contents of Tl, Hg and As are high, suggesting that the residents
and villagers in the mining district have been affected by Tl-Hg pollution, and on the other hand, they can serve as the guidelines
for ore prospecting. The contents of Tl, Hg, and As in human beings and other organic bodies depend largely on the background
values of these metals in rock, ore, soil and water. 相似文献