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Leaching of granular solids can be described in terms of specific mass transfer functions of a simple mathematical form. The parameters can be determined by column leaching experiments under well known flow conditions. Initially available concentrations are obtained from batch experiments at high dilution. Total concentrations in the solids are determined independently to calculate the available fractions. The determination of the flow pattern is done by radiotracer measurements. Leachates are analyzed by various analytical methods including AAS and INAA. Total concentrations in the solids are determined by INAA preferably. 相似文献
3.
Veado MA Arantes IA Oliveira AH Almeida MR Miguel RA Severo MI Cabaleiro HL 《Environmental monitoring and assessment》2006,117(1-3):157-172
Intense mining activities in Minas Gerais State – Brazil brings out tons of waste to the environment. Considerable concentrations
of toxic elements penetrate the soil, ground waters and rivers. This endangers the environment quality not only in the surrounding
areas but also in ichthyofauna and in more distant areas of cattle raising and agricultural activities. After seasonal floods,
veterinary clinic studies have shown that most animals raised in this region are affected by symptomatologic nervous diseases,
still not clearly diagnosed, which suggests intoxication. These pathologies are mostly noted after floods. Instrumental Neutron
Activation Analysis was applied to determine Al, As, Au, Ba, Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, Hg, K, La, Mg, Mn, Na, Nd, Rb,
Sb, Sc, Sm, Th and Zn in environmental samples. The obtained results show that the water and sediment contaminated with heavy
metals and toxic elements from the Das Velhas River upstream basin, the mining region, carry contamination to the ichthyofauna
and farming region within a distance of approximately 400 km. 相似文献
4.
Jha SK Gothankar S Iongwai PS Kharbuli B War SA Puranik VD 《Journal of environmental radioactivity》2012,103(1):1-6
The concentration of naturally occurring radionuclides 232Th, 238U was determined using Instrumental Neutron Activation Analysis (INAA) in different food groups namely cereals, vegetables, leafy vegetables, roots and tubers cultivated and consumed by tribal population residing around the proposed uranium mine. The study area is a part of rural area K. P. Mawthabah (Domiasiat) in the west Khasi Hills District of Meghalaya, India located in the tropical region of high rainfall that remains steeped in tribal tradition without much outside influence. Agriculture by Jhum (slash and burn) cultivation and animal husbandry are the main occupation of the tribal populations. A total of 89 samples from locally grown food products were analyzed. The concentration of 238U and 232Th in the soil of the study area was found to vary 1.6-15.5 and 2.0-5.0 times respectively to the average mean value observed in India. The estimated daily dietary intake of 238U and 232Th were 2.0 μg d−1 (25 mBq d−1) and 3.4 μg d−1 (14 mBq d−1) is comparable with reported range 0.5-5.0 μg d−1 and 0.15-3.5 μg d−1 respectively for the Asian population. 相似文献
5.
湘江谷地土壤中微量元素铀和钍的含量及分布特征 总被引:2,自引:0,他引:2
本研究利用仪器中子活化法对湘江谷地土壤中的天然放射性元素铀和钍进行了测定。文中报道了该地区不同土类和母质土壤及全区土壤中铀和钍的含量及其分布特征。在该区6种主要类型土壤中,铀和钍的含量分布规律基本相同,即山地草甸土>山地黄棕壤>水稻土>红壤>黄壤>紫色土。全区土壤中铀和钍的平均含量分别为4.20ppm和17.0ppm。该值均高于世界土壤中铀和钍的平均含量(2ppm和9ppm)及地壳平均丰度(2.7ppm和9.6ppm),同时也高于我国其它地区。文中还对该区土壤中铀和钍的比值(Th/U)进行了讨论。 相似文献
6.
Fish is the main food in coastal areas and its analysis for toxic metals has been used as an indicator of the pollution status of the aquatic environment. Several different fish species from the three Indian coasts, Visakhapatnam in the east, Mumbai in the west and Mangalore in the south west and also inland freshwater fish from Nagpur in the central region for comparison were analyzed for up to 20 elements (As, Au, Ba, Br, Cl, Co, Cr, Cu, Fe, Hg, K, Mn, Na, P, Rb, Sb, Sc, Se, Sr, Zn) by instrumental neutron activation analysis (INAA). Dried fish samples in powdered form were irradiated with thermal neutrons in a nuclear reactor followed by high resolution gamma ray spectrometry at different intervals. Several Reference Materials (RMs) of biological origin were analyzed for quality assurance and data validation. Elemental contents in different fish species vary in a wide range depending on the species, its size, location, and aquatic environment. Fish from Mangalore showed highest mean contents of Cr (14.8?±?29.9?µg?g?1), Cu (1005?±?643?µg?g?1) and Sb (849?±?888?ng?g?1) whereas those from Mumbai exhibited highest Hg (2066?±?2146?ng?g?1) and P (20.3?±?4.63?µg?g?1) but lowest Cu (6.30?±?3.10?µg?g?1) contents. Fish from all the regions showed significant amounts of nutrient elements such as Na, K, P, Mn, Fe, Se and Zn as well as some pollutant elements (Br, Cr, Sb, Hg). No regularity in variation of elemental contents with the size was observed. Prawn (Panaeus latisulcatus), a popular fish species from four different regions showed wide variation in elemental contents of Cr, Mn, Fe, Zn, Se, P including toxic pollutants, Sb and Hg. An attempt has been made to calculate daily dietary intake (DDI) for some nutrient elements from Indian fish. Elemental data for Cr, Cu, Fe, Hg, Se, and Zn have been compared with those from other fish exporting countries. 相似文献
7.
Nowadays, much attention is devoted to the study of toxic elements at trace and sub-trace levels in the investigation of particulate matter composition, especially in PM10 and PM2.5. Furthermore, it should be considered that the behavior knowledge is an other important task for understanding such species. Finally, the determination of particular elements with a few data in literature can assume relevant importance in industrial processes (Pd, Rh, Ir, etc. for catalytic pot, Sm, Ce, Eu, etc. for optical fibers and electronic process). In this article, we apply a nuclear technique, i.e. Instrumental Neutron Activation Analysis, for the study of metal composition in fine and coarse fractions. This nuclear technique allows the determination of about 25 elements: for some of them, this is the first determination in the ambient air of Rome. The investigation was performed in a reserved area in downtown Rome during a 15-day intensive campaign. The sampled filters were irradiated at the nuclear reactor Triga Mark II (ENEA-Casaccia Laboratories) at neutron flux of 2.6?×?1012?n?cm?2?s?1 for 32.55?h. The measurements of the γ-ray allow the qualitative and quantitative analysis. The element levels in fine and coarse fractions will be shown with the correlations among some elements being more interesting in the toxicological field: basically, the concentrations are very low. 相似文献
8.
Anicić M Frontasyeva MV Tomasević M Popović A 《Environmental monitoring and assessment》2007,129(1-3):207-219
This study aimed at assessing atmospheric deposition of heavy metals and other elements using the moss genera Brachythecium sp. (B. rutabulum and B. salebrosum) and Eurhynchium sp. (E. hians and E. striatum) collected in autumn 2004 in the urban area of Belgrade. The concentrations of 36 elements (Na, Mg, Al, Cl, K, Ca, Sc, Ti,
V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Tb, Dy, Hf, Ta, W, Hg, Th, U) were determined
in moss and local topsoil samples by instrumental neutron activation analysis. The concentration of elements in moss positively
correlated to those obtained for topsoil. High enrichment factors for As, Zn, Mo, Br, Sb, Se, Hg and Cl, calculated to continental
crust composition, gave an evidence for anthropogenic impact on urban area, mainly due to intensive vehicular traffic and
fossil fuel combustion. The concentration of elements in moss, characteristic for fossil fuel combustion, obtained in this
study were substantially lower than in the previous investigation (2000) conducted in the area of Belgrade. The level of concentrations
for V, Cr, Ni, and As in moss from this study correlated to those measured for neighboring countries, and were several times
higher than the base-level data from low polluted areas. The level of accumulated elements in both investigated moss genera
were similar and all studied species could be combined for biomonitoring purposes in urban areas. 相似文献
9.
Freitas MC Farinha MM Ventura MG Almeida SM Reis MA Pacheco AM 《Environmental monitoring and assessment》2005,109(1-3):81-95
This paper describes concentration amounts of arsenic (As), particulate mercury (Hg), nickel (Ni) and lead (Pb) in PM10 and PM2.5, collected since 1993 by the Technological and Nuclear Institute (ITN) at different locations in mainland Portugal, featuring
urban, industrial and rural environments, and a control as well. Most results were obtained in the vicinity of coal- and oil-fired
power plants. Airborne mass concentrations were determined by gravimetry. As and Hg concentrations were obtained through instrumental
neutron activation analysis (INAA), and Ni and Pb concentrations through proton-induced X-ray emission (PIXE). Comparison
with the EU (European Union) and the US EPA (United States Environmental Protection Agency) directives for Ambient Air has
been carried out, even though the sampling protocols herein – set within the framework of ITN's R&D projects and/or monitoring
contracts – were not consistent with the former regulations. Taking this into account, 1) the EU daily limit for PM10 was exceeded a few times in all sites except the control, even if the number of times was still inferior to the allowed one;
2) the EU annual mean for PM10 was exceeded at one site; 3) the EPA daily limit for PM2.5 was exceeded one time at three sites; 4) the EPA annual mean for PM2.5 was exceeded at most sites; 5) the inner-Lisboa site approached or exceeded the legislated PMs; 6) Pb levels stayed far below
the EU limit value; and 7) concentrations of As, Ni and Hg were also far less than the reference values adopted by EU. In
every location, Ni appeared more concentrated in PM2.5 than in coarser particles, and its levels were not that different from site to site, excluding the control. The highest As
and Hg concentrations were found in the neighbourhood of the coal-fired, utility power plants. The results may be viewed as
a “worst-case scenario” of atmospheric pollution, since they have been obtained in busy urban-industrial areas and/or near
major power-generation and waste-incineration facilities. 相似文献
10.
Major and trace element in seven different kinds of milk powder were studied. The concentration of 24 elements were determined by ICP-OES method, from these elements 9 elements determined by INAA. The determination of trace element contents of foodstuffs, especially milk as daily drink for all peoples age which being a complex food has great importance. The elemental analysis of milk is important both as an indicator of environmental contamination and because milk is a significant pathway for toxic metal intake and a source of essential nutrients for humans. The major elements are Ca, K, Mg, Na, P and S. While trace element are B, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sb, Se,Sn, Sr, V, W and Zn.ICP-OES technique is shown to be a powerful tool for trace determinations in powder samples. This is shown by its use for analysis of aseries of the milk powders mentioned and comparative results of other direct technique such as instrumental neutron activation analysis. Analysis of both standard reference material A-Ⅱ milk powder and NBS Orchard leaves for quality accurance had been completed, and used for a relative method calculate. The importance of the major and trace elements to human health was discussed 相似文献