scholarly journals Radiological and physicochemical properties of red mud based geopolymers

2018 ◽  
Vol 33 (2) ◽  
pp. 188-194
Author(s):  
Ivana Boskovic ◽  
Snezana Nenadovic ◽  
Ljiljana Kljajevic ◽  
Ivana Vukanac ◽  
Nadezda Stankovic ◽  
...  

A significant amount of red mud generated as a by-product of the Bayer process in the aluminum industry may cause environmental problems if appropriate treatment is not carried out. The presented research dealt with the possibility of application of red mud as a pigment or as raw material for use in the construction material industry. In relation to the aim of this work, the physicochemical characterization was performed and the natural radioactivity of red mud as an industrial waste and a geopolymer sample based on it was determined. The presented research is a contribution to the potential solution for environmental protection through the synthesis of possible construction material based on red mud. The radiological hazard orginating from 226Ra, 232Th, and 40K in the samples was assesed throught the absorbed dose rate and the annual effective dose rate, calculated in accordance with the UNSCEAR 2010 report. Physicochemical characterization of all samples was conducted using X-ray diffraction and diffuse reflectance infrared Fourier transform spectroscopy.

2018 ◽  
Vol 68 (330) ◽  
pp. e155
Author(s):  
M. Ivanović ◽  
Lj. Kljajević ◽  
M. Nenadović ◽  
N. Bundaleski ◽  
I. Vukanac ◽  
...  

The aim of this study was determination of physical-chemical and radiological characteristics of kaolin and products of alkali-activated thermally treated kaolin (geopolymer). Also, the objective of presented research was to investigate the possibility of kaolin application as a pigment or as a raw material for obtaining geopolymer materials as a relatively new ones in a building material industry. Physicochemical characterization of one set of samples was conducted using X-ray diffraction (XRD), Fourier transform infra - red (FTIR) and X-ray photoelectron spectroscopy (XPS). Activity concentration of naturally occurring radionuclides in kaolin, metakaolin and geopolymer were determined. The absorbed dose rate (D) and the annual effective dose rate (EDR), calculated in accordance with the UNSCEAR 2000 report, are also presented in this paper. Kaolin was heat-treated on 750oC and specific activity of natural radionuclide in metakaolin increased up to 1.6, while measured specific activities in geopolymer were the lowest.


2019 ◽  
Vol 188 (1) ◽  
pp. 98-108
Author(s):  
F O Wanjala ◽  
N O Hashim ◽  
D Otwoma ◽  
C Nyambura ◽  
J Kebwaro ◽  
...  

Abstract The activity concentration of radionuclides 238U, 232Th and 40K in soil and the absorbed dose rate (ADRA) at 1 m above the ground in Ortum was determined. The activity concentration in soils ranged from 33 to 85, 20 to 67 and 148–1019 Bq kg–1, respectively with an average of 40 ± 1.43, 56 ± 1.46 and 425 ± 19.24 Bq kg–1, respectively. The activity concentration of 232Th and 238U was found to reduce with increasing depth while that of 40K increased with increasing depth. The average activity concentration in soil was higher than the world average values. The average ADRA in air at 1 m above the ground was found to be 112 ± 29.6 nGy h–1. The soil and rocks in Ortum are recommended for use because the activity concentration of the terrestrial radionuclides is lower than the recommended threshold values.


2018 ◽  
Vol 53 (4) ◽  
pp. 265-278 ◽  
Author(s):  
S. Penabei ◽  
D. Bongue ◽  
P. Maleka ◽  
T. Dlamini ◽  
Saïdou ◽  
...  

In order to assess the levels of natural radioactivity and the associated radiological hazards in some building materials of the Mayo-Kebbi region (Chad), a total of nineteen samples were collected on the field. Using a high resolution γ-ray spectrometry system, the activity concentrations of radium (226Ra), thorium (232Th) and potassium (40K) in these samples have been determined. The measured average activity concentrations range from 0.56 ± 0.37 Bq kg−1 to 435 ± 7 Bq kg−1, 1.3 ± 0.6 Bq kg−1 to 50.6 ± 1.1 Bq kg−1 and 4.3 ± 2.0 Bq kg−1 to 840 ± 9 Bq kg−1, for 226Ra, 232Th and 40K, respectively. The highest 226Ra average activities is found in soil brick samples of Zabili. The highest mean value of 232Th and 40K concentrations are found in soil brick samples of Madajang. The activity concentration and the radium equivalent activity (Raeq) have been compared to other studies done elsewhere in the world. Their average values are lower than most of those of countries with which the comparison has been made. Were also evaluated, the external radiation hazard index, the internal radiation hazard index, the indoor air absorbed dose rate, the outdoor air absorbed dose rate, the activity utilization index, the annual effective dose, the annual gonadal dose equivalent, the representative level index, as well as, the excess lifetime cancer risk. In accordance with the criterion of the Organization for Economic Cooperation and Development, our results show that soil brick samples of Zabili and Madajang increases the risk of radiation exposure, thereby the possibility of developing cancer by people living in this environment. Based on these findings, brick samples from Zabili and Madajang are not recommended for construction purposes. All other sample materials have properties that are acceptable for use as building materials in terms of radiation hazard.


2001 ◽  
Author(s):  
J M Carson ◽  
P B Holman ◽  
R B K Shives ◽  
K L Ford ◽  
C T Harper ◽  
...  

2020 ◽  
Vol 24 (3) ◽  
pp. 435-442 ◽  
Author(s):  
M. Atipo ◽  
O. Olarinoye ◽  
B. Awojoyogbe ◽  
M. Kolo

Mineral mining and milling can be a source of national economic and technological development. However, mining of minerals has been confirmed to disturb the natural distribution of radioisotopes in the soil, air and water bodies in the biota. In an attempt to evaluate the radiological burden resulting from tin mining activities at Rayfield-Du area of Jos, the background gamma-radiation level in the mine was measured via a well calibratedhand-held dosimeter placed at 1 m above ground level. The mean absorbed dose rate, annual effective dose rate and excess lifetime cancer risk for the mine was 0.83 μSvh-1; 1.44 mSv-1 and 0.005 respectively. Generally, dose rates were higher in the mine pits and processing areas as compared to administrative areas of the mine. The mean measured dose rate and calculated dose parameters for the mine were all high when compared to the regulatory limit for public exposure. The potential of developing radiation-induced health defects as a result of high radiation absorbed dose rate by the miners and dwellers around the mine is highly probable.  Keywords: Gamma-radiation; mine; absorbed dose rate; radiation exposure.


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