The Oligocene–Pleistocene aquifer system in West Mallawi, El Minya Governorate, Egypt, serves as a critical groundwater resource supporting domestic, agricultural, and industrial activities in a region characterized by aridity and scarce surface water availability. Rapid population growth and increasing dependence on groundwater for irrigation have intensified concerns about aquifer depletion and deteriorating water quality. This study provides one of the first comparative hydrochemical assessments of groundwater quality between 2016 and 2024 in the under-monitored West Mallawi aquifer, integrating established multivariate statistical and geochemical modeling techniques within a consistent analytical framework to evaluate changes between two sampling campaigns. Key physicochemical parameters—including pH, electrical conductivity (EC), total dissolved solids (TDS), and major ion concentrations—were evaluated using geochemical modeling, multivariate statistics, and water-quality indices (WQI). Results indicate a marked decline in groundwater quality between the two sampling periods; because the dataset comprises two discrete campaigns rather than a continuous time series, these results describe a comparative change between 2016 and 2024 rather than a verified long-term trend. While pH remained relatively stable (7.6–7.8), EC increased from 1217 to 1327 µS/cm and TDS from 779 to 849 mg/L, both exceeding WHO (2022) drinking-water limits and the Egyptian national standards. Chloride concentrations rose sharply (110 → 287 mg/L), whereas sulfate levels decreased markedly (298 → 89 mg/L). The dominant hydrochemical facies, SO₄–Cl–Na, reflects evaporation, evaporite dissolution, and minor carbonate interaction as key controlling processes. Multivariate analysis of physicochemical variables showed an increase in the variance explained by PC1 from 49.9% (2016) to 60.9% (2024), consistent with an increased influence of salinity-related hydrochemical processes. Groundwater quality deteriorated, with WQI classifications shifting from predominantly Good (WQI 0–50) in 2016 to predominantly Very Poor (WQI 75–100) in 2024. Irrigation water quality also deteriorated due to rising salinity (2490- 3980 µS/cm) hazards. Furthermore, the proportion of samples meeting FAO livestock and poultry water-quality standards decreased from 95.3% (41/43 samples) in 2016 to 86.0% (37/43 samples) in 2024, underscoring mounting salinity stress on agricultural practices. Elevated Cl⁻/HCO3− ratios in 25 samples as of 2024 are indicative of moderate to severe contamination, although, in the absence of independent tracers (e.g., nitrate or isotopic data), this attribution should be regarded as a plausible inference rather than a confirmed source diagnosis. These findings point to increasing vulnerability of the Oligocene–Pleistocene aquifer between the two study periods and underscore the value of sustainable groundwater management and continuous, higher-frequency monitoring to safeguard water resources in West Mallawi.
Antimicrobial photodynamic therapy is one of the effective strategies for facing the resistance of pathogenic microorganisms of traditional antibiotics. In connection with this, new effective compounds are being sought, increasing their biological activity upon irradiation. In this work, a new polypropylene imine (PPI) from the first generation was synthesized and modified with 1,8-naphthalimide, to which a sulfonyl chloride group (D1) was introduced at the C-4 atom, from which after interaction with glucosamine, a dendrimer containing a sulphonamide group (D2) was obtained. The photophysical characteristics of dendrimer D2 were investigated in five organic solvents of different polarity and aqueous media. It was found that the absorption and fluorescence maxima are slightly affected by the polarity of the solvents. Excimer and monomeric fluorescence were also recorded with dendrimer D2 in an aqueous solution …
The need to conserve water is important, as it is predicted that in approximately 20 years there will be a global water shortage. In Mexico and the rest of the world, scientists are constantly looking for methods to help conserve and improve the processes used to treat the wastewater generated and reuse it safely. In this work, Tilapia fish scales modified with acetic acid were used for the removal of heavy metals from model water. For this experiment, the following adsorbent dose range was applied: 0.4 g to 1 g; the pH ranged from 4 to 7; and the contact time varied between 60 and 120 min. A threefactor experimental design was considered, including variables such as the adsorbent dose, contact time, and pH, each at three levels. The chemical modification produced a more porous surface on the flakes, facilitating metal adsorption, as confirmed by morphological and physicochemical analyses. The results obtained confirmed the removal of 94 and 83% of Cd(II) and Pb(II) metal ions, respectively, with an bioadsorbent dose of 1 g at a pH of 4 and a contact time of 120 min for Cd(II) and an adsorbent dose of 0.4 g, a pH of 4, and a contact time of 90 min for Pb(II), with an initial concentration of 200 mg/L for both metals. The Brunauer–Emmett–Teller (BET) analysis results provide critical insights into the textural properties of modified fish scales. The modified fish scales have great potential for removing heavy metals from industrial wastewater.
This study reports the synthesis and performance of a novel nanocomposite, CS@nZVI-CMC NC, consisting of zero-valent iron nanoparticles cross-linked to chitosan and coated to carboxymethyl cellulose. Also, the novelty of this work has been proven by eliminating several heavy metals and pesticides from aqueous solutions and drinking water simultaneously. The NC structure, morphology, size, and functional groups were investigated using advanced techniques such as TEM, SEM, XRD, FTIR, and BET. It showed that the surface area of the NC is found to be 127.95 m2 /g and a pore volume of 0.659 cm3 /g. A spherical shape of the nanoparticles with an average size of 8 ± 2 nm was obtained. The functional groups of the NC such as the –NH, –OH, –C––O, and –CN were demonstrated using the FTIR analysis. The NC shows 96.91 %, 90.00 %, 60.61 %, 52.73 %, and 40.43 % simultaneous removal of Cr(VI), As(V), Cd(II), Pb(II) and Mn(II), respectively. Also, it demonstrates a significant simultaneous elimination of organochlorine pesticides: DDE, heptachlor, endrin aldehyde, endosulfan, and heptachlor epoxide, being 98.52 %, 94.01 %, 70.98 %, 65.39 %, and 63.02 % the elimination percentage, respectively. In addition, the NC exhibited the highest removal (77.09 %) of parathion methyl when simultaneously removing several organophosphorus pesticides. Adsorption mechanisms for the targeted pollutants were also studied, and adsorption and electron transfer were the predominant mechanisms. Therefore, this novel NC could be a promising water and wastewater treatment adsorbent.
