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The scarcity of water resources with increasing demand made the evaluation of groundwater quality an urgent matter. Thus statistical analyses and hydrochemical models were conducted on 111 wells sampled from Pleistocene aquifer at Qena Governorate. Multivariate statistics revealed mixed processes affecting groundwater chemistry. Such processes expressed in terms of four rotated factors; these are mineralization (salinization), anthropogenic surface recharge, dissolution of ferromagnesian minerals, and oxidation factor. Aquifer salinization is evidenced by a lateral change in the basic hydrochemical characteristics from low mineralized Ca–HCO 3 , Mg–HCO 3 , and Na–HCO 3 water types to highly mineralized Ca–Cl, Mg–Cl, and Na–Cl facies. Chloride-water species are associated with high-impact areas of chloride-rich sediments (dissolution of overlain saline sediments and marine Pliocene clay underneath). Piper diagram indicates desert wells are dominantly affected by saltwater intrusion from deep aquifers along fault planes under over-pumping. On other hand, shallow wells are the most affected by surface activities. Likewise, wells located in the vicinity of the industrial zone and sites of wastewater disposal. This raises questions about desert reclamation strategy and its impact on groundwater quality; hence this approach can be used as a basic tool for reviewing desert reclamation management strategies. Quaternary freshwater aquifer in Egypt was exposed to salinization under desert reclamation, via dissolution of marine deposits and intrusion from deeper aquifers. • Quaternary aquifer salinization under desert reclamation was recorded. • Anthropogenic activity is assumed to be the first step in the salinization mechanism. • The aquifer is salinized via the dissolution of salt-bearing sediments. • Saline deep water intrusion under over-pumping is another salinization factor. [ABSTRACT FROM AUTHOR]

River sediments have great impact on water and aquatic life quality. Geochemical and mineralogical composition of River Nile sediments (13 samples) were investigated to differentiate between geogenic and anthropogenic sources of harmful elements at Assiut Governorate, Egypt. The Sediment Quality Index (SQI) and pollution indices were applied. Mineralogically, sediments composed mainly of Quartz (72.3%) followed by Na-albite, anorthite and montmorillonite. Chemical composition is governed by SiO 2 (62.57%) supporting mineralogical composition. Geochemical interrelation indicated the anthropogenic source of As, Cd, and Co as well as the mixed source (geogenic and anthropogenic) of Cr, Cu, Ni, and Zn. Pollution indices showed the minor enrichment of sediments with Cd, Zn, and Cr, moderate pollution with Ni and moderate to severe pollution with Co. Based on SQI, the sediments generally were of good quality with only emerged harmful impact of Cr. Finally, the Nile Sediments quality must be monitored regularly to emphasize the protection of the Nile's environment. • The main mineral in Nile sediments is Quartz followed by albite and montmorillonite. • Cd and Co are the main hazardous metals in the Nile sediments. • Quality indices indicated the acceptable quality of the Nile sediments. • The quality of the Nile sediments degraded from south to north. [ABSTRACT FROM AUTHOR]

This study focuses on the assessment of surface soils from industrially polluted region (El Tebbin) of southern Cairo, Egypt. The impact of agricultural, residential and industrial land use on soils developed from Nile river sediments has significantly compromised their function. Previous evidence has shown that the food chain is contaminated and enhances risk of contaminant exposure of the residential communities. This study investigates factors controlling potentially toxic element (PTE) distribution (Co, Ni, Pb, Cd, Zn, Cr and Cu) in El Tebbin soils and provide estimates of their mobility and bioavailability. The PTE concentrations are characterised by high variability as result of the variety of natural and anthropogenic influences. Highest spatial variability is found for Zn, Cd, Pb and Cu (C.V = 260.0%, 280.4%, 140.8% and 159.6% respectively) and enrichment factors indicate strong anthropogenic inputs. For Co and Ni, relatively low spatial variability (C.V = 65.8% and 45.0% respectively) with depletion in Ni suggests a relatively minor contribution from anthropogenic sources. For Cr, a more uniform distribution pattern showing depletion to minimal enrichment across the study area (C.V = 19.2%) reflects almost exclusive lithogenic control. Using principle component analysis (PCA) to explore concentration data reveals that the major inputs affecting PTE distribution are modified by primary soil properties (texture and pH). Their relative bioavailability (identified through sequential chemical extraction) relates strongly to local input sources. Those elements dominated by lithogenic input (Ni and Co) were found predominantly in soil residual fractions (95.6% and 90.5% respectively), while elements with stronger anthropogenic contributions (Cd, Zn, Pb and Cu) showed much higher portion in the more mobile and bioavailable fractions obtained from sequential chemical extraction, with average proportions of the totals being 62.6%, 57%, 40.7% and 39.2% respectively. Those PTEs with strong anthropogenic influence are potentially much more mobile for bioaccumulation in food chain with increased health risk for exposed residents and are confirmed by elevated concentrations of Cd, Zn, Pb and Cu recorded in local plant species. The main pollution sources were further highlighted by cluster analysis and showed vehicle traffic and specific industrial activities but which varied significantly from site to site. The identification of sources through the approach developed here allows prioritisation of monitoring and regulatory decisions by the local government to reduce further environmental exposure of the local population. [ABSTRACT FROM AUTHOR]

The electronic revolution in recent years points out the importance of rare earth elements (REEs) and trace elements (TEs) in these strategic industries. This study aimed to assess REEs and TEs in black shales from Duwi Formation of two mines, Um Al-Huwaitat and Hamadat, located in the Safaga-Qussier region. The chemical results indicated oxic marine along with warm and humid climate conditions of this sediment deposition. Um Al-Huwaitat Mine was highly enriched with total REEs (average 255.3–325.3 ppm) than Hamadat (average 157–207.4 ppm). Thus, it revealed that the total REEs decreased from Safaga to Qussier direction. The average content of REEs has nearly the same decreasing order of elements; they are arranged in decreasing order: Ce> Y> La> Nd> Sc> Sm and Ce> Y> La> Nd> Sc> Sm for Hamadat and Um El-Huwaitat Mines, respectively. The REEs and TEs concentrations are normalized to the UCC to investigate their distribution patterns. REEs and TEs concentration in the studied samples were higher than UCC, especially Y, Sc, Cs, Co, Zn, Zr, Mo, Cd, Hf, Ta, W, Bi, Se, Br, I, Th and U. The enrichment factor showed that Um Al-Huwaitat black shale is extremely enriched with Y, Cs, Sr, Mo, Cd, W, Bi, Se, I and U; and very high enriched with Ce, Nd, Sc, Co, and Br. La, Sm, Cr, Mn, Ni, Zn, and Th revealed significant enrichment. Clay minerals, especially montmorillonite, have been the major contributor to the enrichment of shale with REEs and TEs. Such findings point towards shale mineralisation with these elements. The current results shed light on the benefit optimization of ceased phosphate mines in the study area through using the associated black shale deposits as a source of REEs and TEs. • Duwi Formation contain mineralized black shale. • Black shale is enriched with rare earth and trace elements. • Re-used the ceased phosphorite mines for extracting associate black shale. [ABSTRACT FROM AUTHOR]