concentration selenium earth
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- concentration selenium earth
Selenium (Se 79 34) is an essential element in living organisms.It is the 30th most abundant naturally occurring metalloid element on the Earth's crust. Selenium is present in the earth's crust at an estimated amount of 0.05–0.5 mg Se kg − 1 (Lemly, 2004), with total selenium concentrations in rocks amounting to 40% of the total earth's crust …
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According to an analysis of 2003–2004 NHANES data, the mean serum selenium concentration in U.S. adults age 40 years or older is 13.67 mcg/dL [ 17 ]. Men have …
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However, high concentration of selenium in water will cause acute or chronic poisoning to animals and human [10]. ... To obtain higher sorption capacity, in our previous work, we reported a layered rare-earth hydroxide (LRH, Y 2 (OH) 5 Cl) with a very high sorption capacity of 207 mg/g for Se(IV) and 124 mg/g for Se(VI) [48]. It is pity that ...
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IOP Conf. Series: Earth and Environmental Science 199 (2018) 042027 IOP Publishing. ... The Effects of six selenium concentrations (0, 5, 10, 25, 50, 75, and 100 mg/kg) on physiological property ...
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Its relative abundance in the Earth's crust is around 1.9 ppb [2]. The primary source can be from the ores with different forms (allotropes) [3]. It also reaches the aquatic environment through rocks, petroleum ... The main goal of this study was to examine selenium concentration levels in two contaminated coastal lagoons. The …
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The concentration of Se in soils is low (0.12–0.77 mg/kg) . According to Qatar General Electricity & Water Company (Kahramaa), Se is not believed to be …
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Distribution of selenium content in the earth crust is extremely uneven, and the mean selenium content is 0.05 mg/kg (Clarke and Washington 1922). Selenium content in the bedrock varies greatly (0.01–56.22 mg/kg), with an average of 2.02 mg/kg, which is higher than the mean selenium content in earth crust (0.05 mg/kg) (Table 4). The …
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Selenium concentrations in sulfide minerals and other phases, in various ... Selenium concentrations in selected Earth and lunar materials ..... Q16 Q6. Estimated world selenium reserves in 2014, in metric tons.....Q21 Q7. National Institutes of Health recommended dietary reference intakes ...
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Distribution of selenium content in the earth crust is extremely uneven, and the mean selenium content is 0.05 mg/kg (Clarke and Washington 1922). Selenium …
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Selenium (Se) is an essential element for humans and animals, with one of the narrowest ranges between deficiency (< 40 µg day−1) and toxicity (> 400 µg day−1). Se is very widespread in all environments (rocks, soils, waters, air, plant and animal tissue) but in very low concentrations. Thus, there are no ores from which Se can be effectively …
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Epidemiological studies that used the selenium concentration in crops as an indicator of dietary selenium have generally reported an inverse association between selenium levels and cancer occurrence. (1,2,4) ... Selenium is a naturally occurring substance that is widely distributed in the earth's crust and is commonly found in sedimentary rock. (1)
به خواندن ادامه دهیدSelenium (Se) is an essential trace element for human health, and humans mainly consume Se through diet. China is recognized as a Se-deficient country, and the study of Se migration and …
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2. Sources of Selenium in the Environment and its Location Most plant and animal tissues contain traces of selenium [11]. It is widespread in the Earth's crust where average concentration is 0.09 mg·kg−1. 2.1. In Soils In soils, selenium occurrence is mainly due to the erosion of rocks containing selenites and
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Selenium concentration in the soil generally ranges from 0.01-2.0 mg kg -1 but seleniferous soils usually contain more than 5 mg kg -1 . ... Selenium (Se) is among the most widely distributed ...
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Selenium (Se) plays an important role in geochemistry and is an essential trace element for humans and animals. This review summarizes the transformation and accumulation of Se in the plant-soil-microbe system. As one of the important reservoirs of Se, soil is an important material basis of its entry into the food chain through plants. Soil …
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Selenium (Se) is a ubiquitous element akin to sulfur (S) existing in the Earth crust in various organic and inorganic forms. Selenium concentration varies greatly depending on the geographic area. Consequently, the content of selenium in food products is also variable. It is known that low Se is associated with increased incidence of cancer …
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Different climate and soil parameters determine how much selenium is concentrated in the soil. As a rule of thumb: if the soil is …
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However, Se is not uniformly distributed throughout the Earth's crust. In certain areas, soil selenium concentrations are between 0.01 and 2 mg/kg, and the world average is 0.4 mg/kg (Fordyce, 2007).
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The concentration of Se in the rocks are low as compared with the anthropogenic sources.-The phosphatic rocks contains very high concentrations of Se.-Se is found together with the deposits of sulfide minerals.-Its distribution depends on the type of rocks.-Earth's crust. 0.05 – 0.09 µg/g: Wang and Gao (2001)-Coal mines. 0.4 – 24 µg/g ...
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3.1 Origin of Soil Selenium and Variable Levels in the Earth's Crust. Total Se concentrations are low in most soils, usually in the range 0.01–2.0 mg kg −1, although levels as high as 1,200 mg kg −1 can occur in seleniferous soils [].The average concentration of Se is much higher in some of the common sedimentary rocks, …
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The concentration of selenium in surface water and groundwater can reach hundred to thousand μg/L, while the selenium content in industrial wastewater has a wide range with the maximum concentration higher than 12 mg/L. High level of selenium in water can cause serious negative impacts on the health of the aquatic habitats, …
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aquatic life criterion for selenium using the best available science. In 2004, EPA published the first draft of the updated selenium criterion using fish-tissue concentrations. In 2009, EPA participated in an expert workshop on selenium and in 2010 collaborated with the U.S. Geological Survey to develop a selenium bioaccumulation model. As a
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the Latin word for earth, tellus (Klaproth, 1798), ... Selenium concentrations in air primarily depend on. coal-burning power plants, copper-refining plants or selenium rectifier plants,
به خواندن ادامه دهیدIn inland lakes, the concentration of Se is ~25 µg/liter . Se is also found in the atmosphere as a component of ash produced by the volcanic activity and burning of fossil fuels. The level of Se in the air near the Earth surface ranges from 0.1 to 10 ng/m 3, whereas its local concentration in certain areas may be as high as 500 ng/m 3 .
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The concentration of selenium in the soil is different from one region to the next. Humans absorb selenium primarily through plant-based foodstuffs. But even in plants, the selenium content varies greatly …
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Se is a non-metallic element naturally present in the earth's crust; the global average concentration of Se in soil is 0.4 mg kg −1, ranging from 0.01 to 2 mg kg −1 (Dungan and Frankenberger Citation 1999). The …
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plants in selenium cycling to the animal and the return of selenium to the soil. Geochemistry Selenium is widely distributed in trace amounts in nearly all materials of the earth's crust, having an average abundance of about 0.09 ppm.' Selenium is only seidom present in concentrations greater than 500 ppm . It
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Selenium belongs to the group of trace elements, with the average concentration of Se in the Earth's crust estimated at 0.05 mg kg −1 (Taylor and McLennan 1995).The Se concentration in the Earth's crust is ~0.09 mg Se kg −1 (NRC 1983).It is located in the group VI of the periodic table.
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The concentration of selenium in soils of China. Globally, typical Se values of soil are between 0.01 and 2.00 mg·kg −1, with a mean of 0.40 mg·kg −1 (Neal, 1995; …
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In this work, sources, global production, uses, bioavailability, daily dietary intakes and global status of Se in soils, waters, plants, atmosphere and plants have been …
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