Nile River is the valued natural and exclusive source of fresh water in Egypt, where the drinking water supply is limited to the river. The water quality of 24 sites between Aswan and Cairo along the Nile was investigated. To evaluate the suitability of water for aquatic life and drinking purposes, the indices of water quality (WQI), heavy metal pollution (HPI) and contamination (Cd) were computed. The water quality variations were mainly related to inorganic nutrients and heavy metals, where, the sites affected by intensive load of urban, agricultural and industrial wastewater showed serious deterioration of water quality compared with other sites. The anthropogenic impact sites showed high HPI and Cd values and associated with high risks, where, most of the studied metals often exceeded the drinking water and aquatic life limits. The aquatic WQI indicated that the Nile water quality deteriorated and extended from poor to marginal, while drinking WQI varied from marginal to good. Accordingly, the river becoming unfit for aquatic life and the situation is getting worse by decreases in the water budget from the Nile in Egypt by building of the Grand Ethiopian Renaissance Dam, where the dilution strength of the Nile system will reduce

The concentration of some heavy metals Fe, Mn, Cu, Zn, Pb, Cd and Hg in various vegetables (roots, stems, leafy, fruits, cereals and legumes) grown in four major industrial and urban cities (Tabouk, Riyadh, Damamm and Jazan) in Kingdom of Saudi Arabia was assessed using atomic absorption spectrophotometer. The obtained results declared that concentrations of major studied metals were exceeding than the recommended maximum acceptable levels proposed by the Joint FAO/WHO Expert Committee on Food Additives. Leafy vegetables were found to contain the highest metals values especially parsley (543.2 and 0.048μg/g for Fe and Hg respectively), Jews mallow (94.12 and 33.22μg/g for Mn and Zn respectively), spinach (4.13μg/g for Cd). While peas in legumes group maintained the highest Zn content 71.77μg/g and finally cucumber had the highest Pb content 6.98μg/g on dry matter basis. High concentrations of heavy metals in different parts of the vegetables might be related to their concentration in the polluted air with industrial activities especially in middle and eastern districts. The study concludes that atmospheric depositions and marketing systems of vegetables play a significant role in elevating the levels of heavy metals in vegetables having potential health hazards to consumers of locally produced foodstuffs

The enhancing breakdown of dyes using facile, novel and eco-friendly photocatalyst without remaining any hazards secondary intermediates from the dye species regarded one of the most challenges to the healthy world. A novel facile method was used to synthesize reduced graphene oxide (rGO) with various doping ratios of silver nanoparticles (Ag NPs) and applied as photocatalyst to enhancing removal of Congo red (CR) dye using UV light irradiation from aqueous solution. Some characterization features such as UV-diffuse reflectance spectra, TEM, SEM, FTIR, X-ray diffraction, and EDX were measured to demonstrate the energy gap, morphology, size distribution, crystalline nature, phase structure, and elemental compositions of as-synthesized nanoparticles. The effect of some important factors such as pH of solution, initial CR concertation (Co), amount of rGO@Ag (g) and contact time (t) were studied to detect the optimum adsorption condition. The results indicated that, the maximum CR dye photodegradation is obtained at pH 7, 120 min, 50 mg/L initial CR concentration and 0.4 g/L photocatalyst dosage. The photodegradation data declared that, the higher the Ag doping ratio, the higher the degrading efficiency. Isotherm and kinetic studies showed that Langmuir and Freundlich models and the pseudo-second-order model are well fitting the adsorption process with maximum CR adsorption values ranging between 86.95 and 98.04 mg/L with corresponding R² > 0.99.

Increasing concern about environmental pollution attracts researchers to develop eco-friendly, low-cost, and sustainable approaches for green biosynthesis of nanoparticles to overcome pollutants. This study focuses on the green synthesis of ceria NPs using Spirulinaplatensis extract as a stabilizing and reducing agent. Characterization measurements, such as optical properties, X-ray diffraction, SEM, TEM, and FT-IR spectroscopy, confirmed the successful synthesis of crystalline and stable ceria NPs with well-defined morphological features. The calculated bandgaps energy of pure ceria, green CeO₂@Sp 2:1, and CeO₂@Sp 1:1 were 3.3, 3.15, and 2.94 eV, respectively. The as-synthesized and green ceria NPs showed an excellent degradation efficacy of MB dye under UV irradiation. Furthermore, the green ceria NPs showed high photodegradation efficiency of MB dye (R% = 86.2 and 88.8%) than pure ceria (R% = 76.4%) at certain specific conditions (pH = 11, contact time = 90 min, catalyst dose = 0.3 g/L and MB dye initial concentration = 100 mg/L). The isothermal constants confirmed that the degradation of MB dye is well-fitted with the Freundlich isotherm model (R² > 0.99) better than the Langmuir model (R² < 0.8). The kinetics models revealed a rapid degradation rate of MB dye, which follows pseudo-second-order models with C_e values ranging from 83.33 to 89.29 mg/g, with R² > 0.99. These results indicated the potential applicability and promising avenue for developing advanced ceria NPs for wastewater treatment applications.