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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.