Abstract:
:It is very important to calculate the radioactivity concentration for low-grade monazite ore (50%) and different other materials produced as results of chemical processing stages to avoid the risk to workers. Chemical processing of low-grade monazite pass through different stages, washing by hydrochloric acid and digested with sulfuric acid and influence of pH on the precipitation of rare earth elements has been studied. The radioactivity concentrations of 238U(226Ra) and 232Th as well as 40K were calculated in crude low-grade ore and found to be 54,435 ± 3138, 442,105 ± 29,200 and 5841 ± 345 Bq/kg, respectively. These values are greatly higher than the exempt levels 25 Bq/kg. After chemical digestion of the ore, the results demonstrated that un-reacted material contains significant radioactivity reached to approximately 8, 13 and 23% for 238U, 232Th and 40K, respectively. The results show that 60% of 232Th are located in the digested white slurry with small portions of 238U and 40K. Most of 238U radioactivity is extracted in the green phosphoric acid which produced from conversion of P2O5 by H2SO4 into phosphoric acid. The average values of the Raeq for monazite ore, un-reacted black precipitate, white precipitate, brown precipitate and crystalline material samples were calculated and found to be 687,095 ± 44,921, 85,068 ± 5339, 388,381 ± 22,088, 313,046 ± 17,923 and 4531 ± 338 Bq/kg, respectively. The calculated values of Raeq are higher than the average world value (it must be less than 370 Bq/kg). Finally the external hazardous, internal hazardous and Iγr must be less than unity. This means that specific radiation protection program must be applied and implemented during monazite processing.
journal_name
J Environ Radioactjournal_title
Journal of environmental radioactivityauthors
Hamed MM,Hilal MA,Borai EHdoi
10.1016/j.jenvrad.2016.05.028subject
Has Abstractpub_date
2016-10-01 00:00:00pages
166-171eissn
0265-931Xissn
1879-1700pii
S0265-931X(16)30191-6journal_volume
162-163pub_type
杂志文章abstract::Protection of the environment post-mining is a key objective of rehabilitation, especially where runoff and erosion from rehabilitated mine sites could potentially lead to contamination of the surrounding land and watercourses. As part of an overall assessment of the success of rehabilitation at the former Nabarlek ur...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2007.08.015
更新日期:2008-03-01 00:00:00
abstract::A new winter and summer investigation of radon concentrations in parts of the Ogof Ffynnon Ddu system at Penwyllt, South Wales, has been carried out using 100 environmental National Radiological Protection Board track etch detectors. Fifty detectors were installed in the system in December 1998 and again in August 199...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/s0265-931x(01)00029-7
更新日期:2002-01-01 00:00:00
abstract::The Sidi Moussa lagoon, located in western coastal Morocco and ranked as a wetland of biological and ecological importance (Ramsar site), is contaminated due to its proximity to the industrial phosphate plants and other anthropogenic activities around it. This study was carried out to assess the current environmental ...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2020.106464
更新日期:2021-02-01 00:00:00
abstract::Micro-SWIFT SPRAY (MSS) is a 3D Lagrangian particle dispersion model that maintains a good balance between accuracy and computational cost. However, its capabilities for air dispersion modeling in the presence of both complex topography and high building densities have not been investigated for nuclear emergency respo...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2020.106341
更新日期:2020-10-01 00:00:00
abstract::Air samples were taken at various locations around The University of Texas at Austin's TRIGA Mark II research reactor and analyzed to determine the concentrations of 37Ar, 41Ar, and 133Xe present. The measured ratio of 37Ar/41Ar and historical records of 41Ar releases were then utilized to estimate an annual average r...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2016.11.017
更新日期:2017-02-01 00:00:00
abstract::Representative large-scale soil sampling on a regular grid of step width about 1 km was carried out for the first time in the near zone of the Chernobyl accident (radius 36 km). An integrated map of terrestrial 90Sr contamination density in the 30 km exclusion zone (scale 1:200,000) has been created from the analysed ...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/s0265-931x(00)00207-1
更新日期:2001-01-01 00:00:00
abstract::The root uptake of radiocaesium by different plant parts of Swiss chard (Beta vulgaris L. var. cicla), cabbage (Brassica oleracea L. var. capitata) and sweet corn (Zea mays L. var. saccharata) and the potential influence of K-fertilising on the transfer behaviour was studied in allophanic volcanic soils (umbric andoso...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2018.06.003
更新日期:2018-12-01 00:00:00
abstract::The disequilibrium of the grandparent-daughter pair 210Pb (t1/2=22.3 years)-210Po (t1/2=138 days) has been used to estimate the export fluxes of particulate organic carbon in the ocean using particulate-matter-associated 210Po. 210Po is produced from 210Bi, not from 210Pb. The half-life of 210Bi (t1/2=5.01 days) is su...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2019.106024
更新日期:2019-11-01 00:00:00
abstract::Tritium emissions are one of the main concerns with regard to CANDU reactors and Canadian nuclear facilities. After the Fukushima accident, the Canadian Nuclear Regulatory Commission suggested that models used in risk assessment of Canadian nuclear facilities be firmly based on measured data. Procedures for measuremen...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2015.08.021
更新日期:2015-12-01 00:00:00
abstract::Chemical analyses and radioecological methods were combined in order to estimate the sediment accumulation rate in the upper 20 cm depth of the Palmones River estuary. Organic matter, total carbon, C:N and (137)Cs vertical profiles showed changes at 13 cm depth. These changes could be associated with the decrease in r...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/S0265-931X(02)00102-9
更新日期:2003-01-01 00:00:00
abstract::An intercomparison of atmospheric dispersion models has been carried out for a hypothetical accident occurring in a nuclear power plant in the center of Spain. The accident consisted of a steam generator tube rupture, and two radionuclides have been considered for the exercise: 137-Cs and 131-I. Meteorological conditi...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2016.05.027
更新日期:2016-10-01 00:00:00
abstract::The Don River Estuary-Azov Sea system is an extension of the shallow continental shelf area of the Black Sea. A large data set of artificial radionuclides in bottom sediments of the Azov Sea has been compiled in order to examine the storage and migration of radionuclides within this highly restricted inland sea and to...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/s0265-931x(01)00081-9
更新日期:2002-01-01 00:00:00
abstract::Crude steel production in China made up the majority of the global output, at 49.5% in 2014. High temperature smelting processes result in the release of natural radionuclides, including radon gas and other air pollutants into the atmosphere. This paper conducts an analysis of the raw materials, end products and flue ...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2018.08.002
更新日期:2018-12-01 00:00:00
abstract::Radon (222Rn), a radioactive gas with a half-life of 3.82 days, is continuously emanated from soil, rocks, and water by the radioactive decay of 226Ra. Radon-222 is released from the ground into the atmosphere, where it is transported mainly by turbulent diffusion or convection. For precise measurement of radon-222 at...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2017.02.008
更新日期:2017-05-01 00:00:00
abstract::The potential use of mycorrhiza as a bioremediation agent for soils contaminated by radiocesium was evaluated in a greenhouse experiment. The uptake of (137)Cs by cucumber, perennial ryegrass, and sunflower after inoculation with a commercial arbuscular mycorrhizal (AM) product in soils contaminated with (137)Cs was i...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2012.08.004
更新日期:2013-01-01 00:00:00
abstract::Plants are used as representative reference biota for the biological assessment of environmental risks such as ionizing radiation due to their immobility. This study proposed a faster, more economical, and more effective method than conventional cytogenetic methods for the biological dosimetry of ionizing radiation in...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2017.11.007
更新日期:2018-01-01 00:00:00
abstract::The Southern Yellow Sea (SYS) is suffering from the increasing environment problems, such as the recurrent algal bloom. The 210Po/210Pb disequilibrium is very useful for assessing particulate organic matter dynamics during phytoplankton blooming. In this study, 23 surface samples were collected from the SYS after the ...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2019.05.017
更新日期:2019-10-01 00:00:00
abstract::During 1998 regional surveys were conducted to evaluate natural radiation exposure of people in the vicinity of the six Spanish nuclear power stations. Indoor radon, external gamma dose rates outdoors and indoors and radioactivity in soil were measured in these surveys. The highest mean annual effective dose to the po...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2004.08.008
更新日期:2005-01-01 00:00:00
abstract::The migration of the uranium (U) in high-level radioactive waste that is held in deep geological repositories via fractures in deep granite aquifers is a serious safety concern, thus, this study investigates the effect of fracture filling materials designed to mitigate these concerns. Geochemical analysis was conducte...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2020.106440
更新日期:2020-12-01 00:00:00
abstract::A total of 88 seawater samples were collected during two Russian research expeditions (April-May 2011 and August-September 2012) to the Sea of Japan, the Oyashio Current region near Kuril Islands and the Kuroshio-Oyashio transition area in the western North Pacific Ocean. The observations were made aboard the R/V Pave...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2014.03.016
更新日期:2014-09-01 00:00:00
abstract::It is well known that the marine organisms are used as biological indicators for environmental pollution studies. Among these studies, the research on oxidative stress has been increasing in recent years. In this study, mussels (Mytilus galloprovincialis) and fish (Solea solea) samples were collected seasonally from İ...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2018.03.018
更新日期:2018-09-01 00:00:00
abstract::The spatial distribution and behaviour of the global fallout (137)Cs in the tropical, subtropical and equatorial soil-plant systems were investigated at several upland sites in Brazil selected according to their climate characteristics, and to the agricultural importance. To determine the (137)Cs deposition density, u...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2007.07.017
更新日期:2008-02-01 00:00:00
abstract::This paper reports the output of a consensus symposium organized by the International Union of Radioecology in November 2015. The symposium gathered an academically diverse group of 30 scientists to consider the still debated ecological impact of radiation on populations and ecosystems. Stimulated by the Chernobyl and...
journal_title:Journal of environmental radioactivity
pub_type: 共识发展会议,杂志文章
doi:10.1016/j.jenvrad.2016.03.021
更新日期:2016-07-01 00:00:00
abstract::The European Commission's Joint Research Centre organizes proficiency tests (PT) on radon-in-water measurements. In order to optimize sampling, transport and measurement methods many tests and small scale proficiency tests have been performed. The waters from natural springs, wells were sampled on-site in glass bottle...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2018.11.012
更新日期:2019-02-01 00:00:00
abstract::A biokinetic model is presented that simulates the uptake and release of (99)Tc by the European lobster (Homarus gammarus). This organism is of significant radioecological interest since lobsters, in contrast to most other organisms, have a high affinity for (99)Tc. The model is designed to represent annually averaged...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/S0265-931X(03)00002-X
更新日期:2003-01-01 00:00:00
abstract::The dispersion of 222Rn from the planned remediation of the Ranger U mine in the wet-dry tropics of Northern Australia was modelled. Dry and wet season contour maps of 222Rn dose normalised to 226Ra activity concentration in the proposed waste rock substrate on the remediated landform were developed. Three example exp...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2018.07.024
更新日期:2018-12-01 00:00:00
abstract::Data on radionuclide transfer to domestic chickens and ducks obtained from research performed in the former Soviet Union were reviewed to provide transfer coefficient values (Ff) to poultry and edible egg contents. The majority of the data are from experiments with (90)Sr and (137)Cs, reflecting the importance of thes...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章,评审
doi:10.1016/j.jenvrad.2009.06.009
更新日期:2009-10-01 00:00:00
abstract::In this work we present the results of a 2-year survey of indoor radon variations in four cities of Lahijan, Ardabil, Sar-Ein and Namin in North and Northwest Iran. We used both passive and active measurements by solid state nuclear track detectors (SSNTDs) with CR-39 polycarbonate and PRASSI Portable radon Gas Survey...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2007.01.013
更新日期:2007-01-01 00:00:00
abstract::The interactions of soil disaggregation with radionuclide erosion were studied under controlled conditions in the laboratory on samples from a loamy silty-sandy soil. The fate of 134Cs and 85Sr was monitored on soil aggregates and on small plots, with time resolution ranging from minutes to hours after contamination. ...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2004.02.004
更新日期:2004-01-01 00:00:00
abstract::Most commercially based activated charcoal radon collectors were designed for use in indoor environments. However, at present, they are often used for research in radon surveys in unique environments, such as in the bathrooms, underground areas, mines, caves and tunnels. In these environments, the relative humidity wo...
journal_title:Journal of environmental radioactivity
pub_type: 杂志文章
doi:10.1016/j.jenvrad.2004.03.037
更新日期:2005-01-01 00:00:00