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1.
Appl Radiat Isot ; 186: 110272, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35567935

RESUMO

The present work aims to radiologically characterize five samples (monazite, zircon, scale waste originating from petroleum production, black sands and phosphate rocks) from different industrial applications and environments in the Egyptian territory. The first section of the present work discusses the measurement and analysis of 226Ra, 232Th and 40K concentrations. Moreover, the assessment of the hazard indices is given in terms of radium equivalent (Raeq), external hazard index (Hex), internal hazard index (Hin), gamma-activity index (Iγ) and alpha-activity index (Iα). The second section deliberates the 222Rn gas emanated from the samples and studies the physical parameters affecting the emanation process. The results found that the monazite sample has the highest concentration of 226Ra, 232Th and 40K; however, it reached 54435, 442105 and 583 Bq.kg-1, respectively, between the studied samples. Furthermore, black sands and phosphate rock samples exhibit the lowest concentration of 226Ra, 232Th and 40K. Results also show that the radon emanation coefficients decrease while the density of materials increases.


Assuntos
Monitoramento de Radiação , Rádio (Elemento) , Radônio , Fosfatos/análise , Rádio (Elemento)/análise , Radônio/análise , Areia , Análise Espectral
2.
J Hazard Mater ; 403: 123945, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33264990

RESUMO

Sorption of fission products onto polycondensed aluminosilicates (PC-AS(s)) is a relatively recent and gets out the mechanisms by which the formers are trapped. Here, PC feldspar (PC-FD), perlite (PC-PR) and their blend (PC-FDPR) were synthesized by the alkaline activation using Na-/K-silicates at Si-modulus of 1.35. XRD patterns revealed the semi-crystalline natures of sorbents. Na- and K-feldspars were detected in PC-FD while Na-based carbonate crystals were detected in others. Components of the poly(sialate-disiloxo) structure were detected in FT-IR spectra. Thermographs were deconvoluted and the amounts of the sticking and zeolitic water were estimated. Kinetic batches for sorption of 134Cs and 152+154Eu onto the elaborated yields were constructed. Ranking of sorbed amounts (qe) was varied from 134Cs (PC-FDPR>PC-FD>PC-PR) to 152+154Eu (PC-PR>PC-FD>PC-FDPR). Maximum qe was recorded at elevated temperature (323 K) to be 4.28 and 1.45 mg/g for 134Cs/PC-FDPR and 152+154Eu/PC-PR, respectively. Along all batches, chemi-sorption mechanism is common denominator. The effective diffusion coefficients (Di) were in the order of 10-14 m2/s. Both PC-FD and PC-FDPR recorded greater Di values of 134Cs than 152+154Eu. The low values of Ea (kJ/mol) reflected the weak adsorbats-adsorbents interactions. While, the high negative values of ∆S‡ suggested that the studied radionuclides were sorbed in associative reaction mechanism.

3.
Appl Radiat Isot ; 149: 83-88, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31035107

RESUMO

A new approach for extraction of 99Mo tracer as a lighter homolog of Seaborgium (Sg) by three different the ionic liquids are studied. Aliquat-336 [Aliq-336.Cl-] as anion exchange has been used for the preparation of three ionic liquid, namely: ([Aliq-336]+ [SCN]-), ([Aliq-336]+ [S]- ) and ([Aliq-336]+ [Fe(CN)6]-). Their potential extraction of carrier free 99Mo from HNO3 solutions has been evaluated. The obtained results demonstrated that successful extraction of carrier free 99Mo from HNO3 solutions is achieved. The ([Aliq-336]+ [Fe(CN)6]-) is found to give the highest extraction affinity for 99Mo than the others ionic liquids investigated. The preliminary results could be useful for the upcoming aqueous experiments of Seaborgium.

4.
Appl Radiat Isot ; 147: 40-47, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30798204

RESUMO

Increasing in the use of various radioactive elements in many applications over the past few decades has accompanied with an increase radioactive waste. Therefore, preparation of Al2O3ZrO2CeO2 nanocomposite material by sol-gel polymeric method is carried out. The nanocomposite material was characterized by some analytical techniques such as Fourier transform infrared (FTIR), Thermograviemtric & differential thermal analysis (TGA & DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Separation of 134Cs and 90Sr/90Y as a fission product present in radioactive waste effluents using the prepared nanocomposite was investigated. The result showed that removal of 94%, 44% and 8.5% for 134Cs, 90Sr and 90Y, respectively. The experimental results are fitted with pseudo-second-order kinetic model. Isotherm models of sorption process are calculated and it can be concluded that the Langmuir model more fitted than Freundlich model. The calculated thermodynamic functions exhibited that sorption behavior of 134Cs and 90Sr ions are spontaneous in nature and the positive value of ΔHo value indicates that the sorption is endothermic. The results demonstrated that the % sorption of 134Cs(I) and 90Sr(II) is sharply decreased in the presence of coexisting ions (Na, Mg and Cr) using nanoparticles of Al2O3 ZrO2CeO2.

5.
Appl Radiat Isot ; 140: 201-208, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30053669

RESUMO

Humic substances (HS) of the dark-colored are found in all soils and sediments as natural organic matter (NOM). HS has high affinity interacted with various organic and inorganic pollutants. Therefore, the HS were isolated from agriculture soil and their potential to remove radium species (226+228Ra) from TENORM scale waste produced from oil production was investigated. Different factors affecting on the efficient removal of radium species by natural humic and natural fulvic acids (NHA and NFA) were investigated by batch technique. These parameters include contact time, concentration of HS, pH, successive leaching as well as the influence of mixed ratio of NHA and NFA. The experimental results indicate that, higher pH and concentration of HS is capable of leaching out 95.2% and 90.2% from TENORM scale waste by the NHA and NFA, respectively, through 3 successive leaching process. Admixture of NHA and NFA solution has been removed 93% of 226+228Ra from scale waste. It is a novel approach for efficient removal Ra isotopes level from TENORM scale waste by economic and eco-friendly that could be help for design a semi-pilot plant for scale-up test in forthcoming study.


Assuntos
Química Verde/métodos , Substâncias Húmicas , Rádio (Elemento)/isolamento & purificação , Poluentes Radioativos do Solo/isolamento & purificação , Benzopiranos , Concentração de Íons de Hidrogênio , Resíduos Industriais/análise , Indústria de Petróleo e Gás , Resíduos Radioativos/análise
6.
Appl Radiat Isot ; 128: 224-230, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28738251

RESUMO

A combined of various nuclear and analytical techniques were used for characterization of Egyptian zircon ore. Neutron activation analysis has been used for determination of the major, minor and trace elements from zircon ore. Non-destructive gamma-ray technique is also used for the radiometric analysis of zircon ore to quantify the natural radionuclides such as 238U, 235U, 232Th, 226Ra and 40K. Zircon ore has been characterized by different analytical tools such as Fourier transformer infrared (FTIR), X-ray fluorescence (XRF), powder X-ray diffraction (XRD), and scanning electron microscopy (SEM). In this study, a significant concentration of U, Th and rare earth elements (REEs) has been reported. The obtained results showed that the average activity concentration of 238U, 235U, 226Ra, 232Th and 40K are 4771±338, 230±17.1, 3588±125, 982±47.7 and 217±48.5Bq/kg, respectively. The results indicated that 297, 318 and 838mg/Kg for U, Th, REEs, respectively, using NAA. These results are consistent with those obtained by gamma-ray spectroscopy and/or XRF. It can be concluded that zircon ore is a riche with a valuable nuclear materials such as U, Th, Zr, and Hf. It is also containing a REEs of economic and industrial interest. Also, the different radiation hazardous parameters were found much higher than the permissible values.

7.
J Environ Radioact ; 151 Pt 1: 156-165, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26465672

RESUMO

Potential utilization of hematite as a natural material for immobilization of long-lived radionuclides from radioactive liquid waste was investigated. Hematite ore has been characterized by different analytical tools such as Fourier transformer infrared (FTIR), X-ray fluorescence (XRF), powder X-ray diffraction (XRD), thermogravimetry (TG) and differential thermal (DT) analysis, scanning electron microscopy (SEM) and BET-surface area. In this study, europium was used as REEs(III) and as a homolog of Am(III)-isotopes (such as (241)Am of 432.6 y, (242m)Am of 141 y and (243)Am of 7370 y). Micro particles of the hematite ore were used for treatment of radioactive waste containing (152+154)Eu(III). The results indicated that 96% (4.1 × 10(4) Bq) of (152+154)Eu(III) was efficiently retained onto hematite ore. Kinetic experiments indicated that the processes could be simulated by a pseudo-second-order model and suggested that the process may be chemisorption in nature. The applicability of Langmuir, Freundlich and Temkin models was investigated. It was found that Langmuir isotherm exhibited the best fit with the experimental results. It can be concluded that hematite is an economic and efficient reactive barrier for immobilization of long-lived radio isotopes of actinides and REEs(III).


Assuntos
Recuperação e Remediação Ambiental/métodos , Európio/análise , Compostos Férricos/química , Radioisótopos/análise , Poluentes Radioativos da Água/análise , Adsorção , Recuperação e Remediação Ambiental/economia
8.
J Environ Radioact ; 139: 78-84, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25464043

RESUMO

The feasibility of using surfactants as extracting agent for the removal of radium species from TENORM sludge produced from petroleum industry is evaluated. In this investigation cationic and nonionic surfactants were used as extracting agents for the removal of radium radionuclides from the sludge waste. Two surfactants namely cetyltrimethylammonium bromide (CTAB) and Triton X-100 (TX100) were investigated as the extracting agents. Different parameters affecting the removal of both (226)Ra and (228)Ra by the two surfactants as well as their admixture were studied by the batch technique. These parameters include effect of shaking time, surfactants concentration and temperature as well as the effect of surfactants admixture. It was found that, higher solution temperature improves the removal efficiency of radium species. Combined extraction of nonionic and cationic surfactants produces synergistic effect in removal both (226)Ra and (228)Ra, where the removals reached 84% and 80% for (226)Ra and (228)Ra, respectively, were obtained using surfactants admixture.


Assuntos
Rádio (Elemento)/análise , Esgotos/análise , Tensoativos/análise , Poluentes Radioativos da Água/análise , Monitoramento de Radiação
9.
J Environ Radioact ; 136: 121-6, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24949581

RESUMO

In this study, a potential radiation hazard from TENORM sludge wastes generated during exploration and extraction processes of oil and gas was evaluated. The activity concentration of natural radionuclides (238)U, (226)Ra and (232)Th were determined in TENORM sludge waste. It was found that sludge waste from oil and gas industry is one of the major sources of (226)Ra in the environment. Therefore, some preliminary chemical treatment of sludge waste using Triton X-100 was also investigated to reduce the radioactivity content as well as the risk of radiation hazard from TENORM wastes. The activity concentrations of (226)Ra and (228)Ra in petroleum sludge materials before and after chemical treatment were measured using gamma-ray spectrometry. The average values of the activity concentrations of (226)Ra and (228)Ra measured in the original samples were found as 8908 Bq kg(-1) and 933 Bq kg(-1), respectively. After chemical treatment of TENORM samples, the average values of the activity concentrations of (226)Ra and (228)Ra measured in the samples were found as 7835 Bq kg(-1) and 574 Bq kg(-1), respectively. Activity concentration index, internal index, absorbed gamma dose rate and the corresponding effective dose rate were estimated for untreated and treated samples.


Assuntos
Resíduos Industriais/análise , Petróleo/análise , Resíduos Radioativos/análise , Rádio (Elemento)/análise , Tório/análise , Urânio/análise , Egito , Indústrias Extrativas e de Processamento , Resíduos Industriais/prevenção & controle , Monitoramento de Radiação , Resíduos Radioativos/prevenção & controle , Espectrometria gama
10.
Environ Sci Pollut Res Int ; 20(2): 1106-16, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22565983

RESUMO

The present work investigates the potential use of metal hydroxides sludge (MHS) generated from hot dipping galvanizing plant for adsorption of Congo Red and Naphthol Green B dyes from aqueous solutions. Characterization of MHS included infrared and X-ray fluorescence analysis. The effect of shaking time, initial dye concentration, temperature, adsorbent dosage and pH has been investigated. The results of adsorption experiments indicate that the maximum capacity of Congo Red and Naphthol Green B dyes at equilibrium (q(e)) and percentage of removal at pH 6 are 40 mg/g, 93 %, and 10 mg/g, 52 %, respectively. Some kinetic models were used to illustrate the adsorption process of Congo Red and Naphthol Green B dyes using MHS waste. Thermodynamic parameters such as (ΔG, ΔS, and ΔH) were also determined.


Assuntos
Corantes/química , Vermelho Congo/química , Compostos Férricos/química , Naftalenossulfonatos/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias , Poluentes Químicos da Água/química , Adsorção , Concentração de Íons de Hidrogênio , Resíduos Industriais , Cinética , Modelos Teóricos , Temperatura , Termodinâmica , Fatores de Tempo , Eliminação de Resíduos Líquidos/economia
11.
J Hazard Mater ; 244-245: 596-602, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23195600

RESUMO

Phosphogypsum (PG), primary byproduct from phosphoric acid production, is accumulated in large stockpiles and occupies vast areas of land. Phosphogypsum is a technologically enhanced naturally occurring radioactive material (TE-NORM) that contains radionuclides from (238)U and (232)Th decay series which are of most radio-toxicity. The reduction in concentration of radionuclides content from PG was based on leaching of (226)Ra, (210)Pb, (238)U and (40)K using tri-butyl phosphate (TBP) and tri-octyl phosphine oxide (TOPO) in kerosene. The factors which affect the leaching process such as contact time, concentration of the solvent and temperature were optimized. Based on the experimental results, about 92.1, 88.9, 83.4, 94.6% of (226)Ra, (210)Pb, (238)U and (40)K respectively were successfully removed from the PG. The reduction in the concentration of radionuclides was accompanied by reduction in the concentration of rare earth elements (∑REE) equals to 80.1%. Using the desired organic extractant under optimum conditions for treatment of the PG waste leads to obtain a decontaminated product that can be safely used in many industrial applications.


Assuntos
Sulfato de Cálcio/química , Organofosfatos/química , Fósforo/química , Poluentes Radioativos/química , Radioisótopos/química , Descontaminação , Resíduos Industriais , Querosene , Mineração , Compostos Organofosforados/química , Fosfatos , Reciclagem , Gerenciamento de Resíduos
12.
J Radioanal Nucl Chem ; 291(3): 907-914, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-26224916

RESUMO

Phosphogypsum (PG) is a residue of the phosphate fertilizer industry that has relatively high concentrations of harmful radioactive materials. The reduction in concentration of the radionuclides from PG was investigated. The removal process is based on leaching of radionuclides using suitable organic extractants. The studied radionuclides were 226Ra, 210Pb, 238U and 40K. The factors affect the leaching process such as type of leaching materials, contact time, concentration of the desired solvent, liquid to solid ratio, and temperature were studied. Based on the experimental results, about 71.1, 76.4, 62.4, and 75.7% of 226Ra, 210Pb, 238U and 40K respectively were successfully removed from the PG. The reduction in the concentration of radionuclides was accompanied by reduction in the concentration of rare earth elements (∑REE) equals to 69.8%. Using the desired organic extractant under optimum conditions for treatment of the PG waste leads to obtain a decontaminated product that can be safely used in many industrial applications.

13.
J Hazard Mater ; 195: 73-81, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21908104

RESUMO

The main goal of this study was to find a novel impregnated resin as an alternative for the conventional resin (KY-2 and AN-31) used for low and intermediate level liquid radioactive waste treatment. Novel impregnated ion exchangers namely, poly (acrylamide-acrylic acid-acrylonitril)-N,N'-methylenedi-acrylamide-4,4'(5')di-t-butylbenzo 18 crown 6 [P(AM-AA-AN)-DAM/DtBB18C6], poly (acrylamide-acrylic acid-acrylonitril)-N,N'-methylenediacrylamide-dibenzo 18 crown 6 [P(AM-AA-AN)-DAM/DB18C6], and poly (acrylamide-acrylic acid-acrylonitril)-N,N'-methylenediacrylamide-18 crown 6 [P(AM-AA-AN)-DAM/18C6] were prepared and their removal efficiency of some radionuclides was investigated. Preliminary batch experiments were performed in order to study the influence of the different derivatives of 18 crown 6 on the characteristic removal performance. Separation of (134)Cs, (60)Co, (65)Zn and ((152+154))Eu radionuclides from low level liquid radioactive waste was investigated by using column chromatography with P(AM-AA-AN)-DAM/DtBB18C6 and metal salt solutions traced with the corresponding radionuclides. Breakthrough data was obtained in a fixed bed column at room temperature (298K) using different bed heights and flow rates. The breakthrough capacities were found to be 94.7, 83.3, 58.7, 43.1 (mg/g) for (60)Co, (65)Zn, (134)Cs, and ((152+154))Eu, respectively. Pre-concentration and separation of all radionuclides under study have been carried out using different concentration of nitric and/or oxalic acids.


Assuntos
Cromatografia por Troca Iônica/métodos , Éteres de Coroa/química , Polímeros/química , Resíduos Radioativos , Radioisótopos/isolamento & purificação
14.
Appl Radiat Isot ; 68(2): 239-49, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19906532

RESUMO

A novel impregnated polymeric resin was practically tested as adsorbent material for removal of some hazardous radionuclides from radioactive liquid waste. The applicability for the treatment of low-level liquid radioactive waste was investigated. The material was prepared by loading 4,4'(5')di-t-butylbenzo 18 crown 6 (DtBB18C6) onto poly(acrylamide-acrylic acid-acrylonitril)-N, N'-methylenediacrylamide (P(AM-AA-AN)-DAM). The removal of (134)Cs, (60)Co, (65)Zn , and ((152+154))Eu onto P(AM-AA-AN)-DAM/DtBB18C6 was investigated using a batch equilibrium technique with respect to the pH, contact time, and temperature. Kinetic models are used to determine the rate of sorption and to investigate the mechanism of sorption process. Five kinetics models, pseudo-first-order, pseudo-second-order, intra-particle diffusion, homogeneous particle diffusion (HPDM), and Elovich models, were used to investigate the sorption process. The obtained results of kinetic models predicted that, pseudo-second-order is applicable; the sorption is controlled by particle diffusion mechanism and the process is chemisorption. The obtained values of thermodynamics parameters, DeltaH degrees , DeltaS degrees , and DeltaG degrees indicated that the endothermic nature, increased randomness at the solid/solution interface and the spontaneous nature of the sorption processes.


Assuntos
Resinas Acrílicas/química , Éteres de Coroa/química , Substâncias Perigosas/isolamento & purificação , Resíduos Radioativos/análise , Radioisótopos/química , Radioisótopos/isolamento & purificação , Ultrafiltração/métodos , Absorção , Simulação por Computador , Descontaminação/métodos , Modelos Químicos
15.
J Environ Radioact ; 100(5): 407-12, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19272681

RESUMO

The present work is directed to characterize the phosphogypsum (PG) wastes associated with phosphoric acid produced by the wet process in industrial facility for the production of fertilizers and chemicals in Egypt. The PG waste samples were characterized in terms of spectroscopic analysis (X-ray diffraction, X-ray fluorescence, IR spectra) and radiometric analysis (gamma- and alpha-measurements). The gamma-ray measurements showed that the average activity concentrations are 140+/-12.6, 459+/-36.7, 323+/-28.4, 8.3+/-0.76 and 64.3+/-4.1 Bq/kg for U-238, Ra-226, Pb-210, Th-232 and K-40, respectively. The alpha-particle measurements of uranium isotopes showed that the average activity concentrations of U-238, U-235 and U-234 were 153+/-9.8, 7+/-0.38, 152+/-10.4 Bq/kg, respectively. The average radiochemical recovery (%) of the destructive alpha-particle measurements is approximately 70% with a resolution (FWHM) of approximately 30 keV. Activity ratios of U-238/Ra-226 and U-238/Pb-210 were less than unity (i.e., <1) and equal to 0.31+/-0.02 and 0.47+/-0.16, respectively. The isotopic ratios of U-238/U-235 and U-238/U-234 (in PG and PR samples) were close to the normal values of approximately 21.7 and approximately 1, respectively and are not affected by the wet processing of phosphate rock (PR). The obtained results of PG waste samples were compared with phosphate rock (PR) samples. The radiation hazard indices are namely, radium activity index (Ra-Eq>370 Bq/kg), total absorbed gamma dose rate (D(gamma r)>5 nGy/h) and radon emanation fraction (Rn-EF>20%). Uncertainty of the sample counting was 95% confidence level of sigma. The results indicated the necessity to find suitable routes to decrease and/or redistribute the radionuclide of environmental interest (i.e., Ra-226) in PG wastes, consequently to reduce its radiation impacts in the surrounding environment.


Assuntos
Sulfato de Cálcio/análise , Fertilizantes/análise , Fósforo/análise , Monitoramento de Radiação/estatística & dados numéricos , Resíduos/análise , Egito , Ácidos Fosfóricos , Monitoramento de Radiação/métodos , Espectrometria por Raios X , Difração de Raios X
16.
Cutis ; 53(3): 134-6, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8187542

RESUMO

A forty-two-year-old man presented with a twelve-year history of a multilobular, firm, but nonulcerated tumor (6 by 4.5 cm) of the dorsum of the right foot. He had capillary telangiectasia of both ankles but no lymphedema. Results of tests for human immunodeficiency viruses I and II were nonreactive. The tumor showed a complex combination of features of spindle cell hemangioendothelioma, epithelioid hemangioendothelioma, and areas suggestive of a possible well-differentiated (lymph) angiosarcoma. The tumor was completely excised with minimal healthy margin. There was no evidence of local or distant lesion at one-year follow-up examination.


Assuntos
Doenças do Pé/patologia , Hemangioendotelioma Epitelioide/patologia , Hemangioendotelioma/patologia , Hemangiossarcoma/patologia , Neoplasias Primárias Múltiplas/patologia , Neoplasias Cutâneas/patologia , Adulto , Humanos , Masculino
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