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This environmental engineering study was conducted to investigate and correlate the fundamental mineralogical compositions of phosphate rock in the Hazm Al-Jalamid area of Saudi Arabia at different layers originating from an open-pit mine. Microbial communities within these layers and the associated correlations between the mineralogical compositions at different geological and textural profiles were investigated. Three representative phosphaterock layers, upper, middle, and lower, were investigated. The dominated crystal structure of the upper layer was calcite, while dolomite, and quartz were in middle and lower layers, respectively. In contrast, Phosphate concentrations reached levels around 3.12%, 7.66%, and 3.92% of the overall content of representative samples in the upper, middle, and lower layers, respectively. The same trends were observed for both fluorapatite and phosphorus pentoxide. The microbiome of the phosphate-ore samples was evaluated. The phylum Proteobacteria dominated the upper and middle layers, while the well-known phosphate-solubilizing bacteria species Pseudomonas putida were present at 46% and 50% in both the upper and middle layers, respectively. In contrast, the actinobacterium Saccharopolyspora flava dominated the lower layer. Increasing selective phyla and species that associated with the elevated content of phosphorus from one layer to another within mine enhanced the understating of these microorganisms as extremophiles.

Water resources are increasingly polluted by toxic heavy metals such as Cadmium (Cd). Cd is particularly dangerous because it accumulates in living organisms leading to diseases affecting the kidneys, bones and lungs. As a result, researchers have been developing effective techniques to remove harmful heavy metals. Currently, purification techniques in Saudi Arabia and other parts of the world are inefficient and costly; thus, the development of a cheap, readily available, and natural material for the removal of Cd is of great interest. This work highlights the adsorptive potential of local Saudi bentonite clay extracted from Khulais region in western Saudi Arabia in the removal of toxic Cd(II) from aqueous solutions. We successfully synthesized bentonite clay beads that can be inserted in columns for filtering purposes. The effects of contact time, bentonite mass, PH, temperature, bentonite treatment (washing and calcinations), and the adsorptive potential of bentonite were evaluated. The results show excellent adsorptive capacity of bentonite.

Gulf countries are often affected by dust storms which have a significant influence on the environment and public health. The present work examines the radioactivity content in the intense dust storm occurred over Gulf countries on 1 April 2015. The results showed that the average value of 137Cs in dust samples (±SD) is 14.4 ± 1.6 Bq/kg, which is almost two orders of magnitude larger than those in soil samples. 7Be was detected with a considerable amount only in dust samples. The activity concentrations of the natural radionuclides (234,238U, 228,230,232Th, 226,228Ra and 40K) in dust samples were found to be approximately two to three times higher than the corresponding values in soil samples, which is attributed to the abundance of the finest particle size in the dust samples. Also, the activity ratios and the correlations between the detected radionuclides were investigated to assess the origin and activities associated with any variation of the radionuclides in the environment. Moreover, the total annual effective dose due to ingestion of dust was estimated to be 89.7 and 34.9 nSv for infants and adults, respectively, which is well below the world average internal dose of 290 µSv. The main contributor to the annual effective dose was 228Ra, which contributes ~69.6 and 43.3% for infants and adults, respectively, followed by: 226Ra » 232,230,228Th > 234,238U > 40k, 137Cs » 7Be. [ABSTRACT FROM AUTHOR]

Grade 92 steel (9Cr-2W) is a ferritic-martensitic steel with good mechanical and thermal properties. It is being considered for structural applications in Generation IV reactors. Still, the irradiation performance of this alloy needs more investigation as a result of the limited available data. The irradiation performance investigation of Grade 92 steel would contribute to the understanding of engineering aspects including feasibility of application, economy, and maintenance. In this study, Grade 92 steel was irradiated by iron ion beam to 10, 50, and 100 dpa at 30 and 500 °C. In general, the samples exhibited good radiation damage resistance at these testing parameters. The radiation-induced hardening was higher at 30 °C with higher dislocation density; however, the dislocation density was less pronounced at higher temperature. Moreover, the irradiated samples at 30 °C had defect clusters and their density increased at higher doses. On the other hand, dislocation loops were found in the irradiated sample at 50 dpa and 500 °C. Further, the irradiated samples did not show any bubble or void. [ABSTRACT FROM AUTHOR]

This study aims to assess the committed effective dose due to the intake of 210 Po from the consumption of fish in Arabian Gulf countries. Twenty different kinds of fish, which represent the most common fish species consumed in the Arabian Gulf countries, were analyzed using alpha spectrometer technique. 210 Po activity concentrations in fish samples were found to vary over a wide range from 0.1 to 14.7 Bq kg -1 fresh weight. This variation of 210 Po concentrations between various type of fish samples might be attributed to the feeding type pattern and the size of fish. The annual committed effective dose due to ingestion of 210 Po in fish species for adults in the Arabian Gulf countries was estimated and found to vary from 38 μSv in Bahrain to 85 μSv in Oman with an average value of 59 μSv. These values are considered relatively high compared to those reported in some other regions. However, it is still much lower than the world average ingestion dose due to natural radiation sources., (Copyright © 2018 Elsevier Ltd. All rights reserved.)