The El-Salam canal in Egypt is considered an important stream of fresh water for the agricultural sector that extends from the Nile River to Sinai, while it is subjected to several anthropogenic stresses. In this study, five-georeferenced stations (named from S1 to S5) were monitored along the El-Salam Canal before El-Sahara of the Suez Canal, via the estimation of the WQ index based on major cations and anions analysis including salinity hazard, permeability index, residual sodium carbonate, magnesium hazard, sodium percentage, sodium adsorption ratio, Kelley index, potential salinity, total hardness, and irrigation water quality index (IWQI). The sequence of average concentration of cations in water were Na⁺ > Ca²⁺ > Mg²⁺ > K⁺. The major cations constitute around 60% of the total dissolved salts. While the sequence of major anions in water were SO₄²⁻ > HCO₃⁻ > Cl⁻ > CO₃²⁻. These cations and anions showed an increasing trend from S1 (intake of the canal) to S5 (before El-Sahara) of the El-Salam Canal. Moreover, the order of heavy metals was Zn < Cd < Cr < Ni < Fe < Mn < Co < Cu < Pb. According to the US EPA (1999) guidelines, the levels of Fe and Zn in the El-Salam Canal are within the permissible limits for drinking and irrigation purposes, while Mn, Pb, Cu, Co, Ni, Cr, and Cd were detected at higher concentrations than those recommended. The value of IWQI in water samples varied from 40.26 to 114.82. The samples of S1 showed good water, the samples of region S2 (after mixing with Faraskour drainage) showed poor water quality, samples of regions S3 (after mixing with the El-Serw drain waters) and S5 (before El-Sahara) fell under the very poor water category and samples of region S4 (after mixing with the Hadous drainage) showed unsuitable water. Croplands irrigated with such water will not be exposed to any alkaline risks but will be exposed to the risk of salinity, which is more severe after mixing at the S3 and S4 sites. It is recommended to treat the drainage water before mixing with the irrigation water of El-Salam Canal to raise the suitability of irrigation water for crops, particularly for the Hadous drain.

In this study, a natural low-coast, efficient, and eco- bio-sorbent plant material (Ludwigia stolonifera), with both parts of the root and shoot, were studied for the removal of the cationic metal ions, lead Pb²⁺ and chromium Cr⁶⁺, via batch mode experiments to evaluate their maximum adsorption capacity, and held a comparison between the used bio-sorbent roots and shoots, based on the highest bio-sorption potential. Optimization of the bio-sorption parameters, such as contact time, pH, bio-sorbent (root and shoot) dosage, and initial ion concentration was conducted. The results indicated that 1.6 g of the used bio-sorbent shoot material removed 81.4% of Pb²⁺, and 77% of Cr⁶⁺ metal ions from liquid media under the conditions of 100 ppm of initial metal ions concentration at room temperature for 60 min of contact time with the static condition. Different isotherms and kinetic models were fit to the experimental data to understand the nature of the bio-sorption process. The experimental data were best fit by the pseudo-second-order kinetic model with a high correlation coefficient (R² = 0.999), which reveals the chemisorption nature of the bio-sorption process. The chemical and structural analysis of the used bio-sorbent, before and after Cr⁶⁺ and Pb²⁺ bio-sorption, were performed using different techniques of characterization, such as Scanning Electron Microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The used bio-sorbent proved to be a low-cost, efficient, and eco-friendly material to remove heavy metal ions from aqueous solutions.

Melanin as a natural polymer is found in all living organisms, and plays an important role in protecting the body from harmful UV rays from the sun. The efficiency of fungal biomass (Aureobasidium pullulans) and its extracellular melanin as Cr(VI) biosorbents was comparatively considered. The efficiency of Cr(VI) biosorption by the two sorbents used was augmented up to 240 min. The maximum sorption capacities were 485.747 (fungus biomass) and 595.974 (melanin) mg/g. The practical data were merely fitted to both Langmuir and Freundlich isotherms. The kinetics of the biosorption process obeyed the pseudo-first-order. Melanin was superior in Cr(VI) sorption than fungal biomass. Furthermore, four independent variables (contact time, initial concentration of Cr(VI), biosorbent dosage, and pH,) were modeled by the two decision trees (DTs). Conversely, to equilibrium isotherms and kinetic studies, DT of fungal biomass had lower errors compared to DT of melanin. Lately, the DTs improved the efficacy of the Cr(VI) removal process, thus introducing complementary and alternative solutions to equilibrium isotherms and kinetic studies. The Cr(VI) biosorption onto the biosorbents was confirmed and elucidated through FTIR, SEM, and EDX investigations. Conclusively, this is the first report study attaining the biosorption of Cr(VI) by biomass of A. pullulans and its extracellular melanin among equilibrium isotherms, kinetic study, and algorithmic decision tree modeling.

The discharge of synthetic dyes into aquatic ecosystems poses a critical threat to environmental and human health, necessitating urgent, cost-effective, and sustainable remediation strategies. This study addresses a practical yet underexplored question in biosorption research: Is the additional energy and processing cost of converting plant-based materials from micro- to Micron-sized porous particles scale justified by a significantly higher dye removal performance? To answer this, we systematically investigate two underutilized and readily available plant species—Zygophyllum coccineum (Zygo) and Calotropis procera (Cal)—as biosorbents for methylene blue (MB) removal from wastewater. Biosorbents at both micro- and Micron-sized porous particles scale were prepared via mechanical ball milling and thoroughly characterized using SEM, XRD, BET, FTIR, and TGA to ensure powerful structural and compositional validation. Ball milling is overall an environmentally friendly and resource-efficient preparation method, facilitating solid waste recycling and cleaner synthesis with lower chemical emissions. The main environmental and economic drawback is relatively high energy consumption, particularly for large-scale or prolonged operations, but this can be managed through process optimization and proper equipment maintenance. When integrated with energy-saving strategies and dust control, ball milling provides a sustainable, circular alternative to conventional, more polluting approaches to material processing and biosorbent preparation. Characterization confirmed enhanced surface area and porosity in Micron-sized porous particles scale materials (e.g., Micron-sized porous particles-Cal: 86.91 m²/g), directly correlating with increased adsorption efficiency. Adsorption experiments, optimized across batch experiments (dose: 0.5 g/L, pH 7, time: 180 min), demonstrated that Micron-sized porous particles-Cal achieved up to 99.5% MB removal at room temperature, significantly outperforming its microscale equivalent and many reported biosorbents. Adsorption data fitting to Langmuir and Freundlich isotherms, and pseudo-second-order kinetics confirmed the presence of both monolayer adsorption and chemisorption-driven mechanisms. Importantly, we integrated an XGBoost machine learning model to predict adsorption performance with high accuracy (MSE: 0.08, RMSE: 0.28, MAE: 0.15), revealing dosage and pH as dominant factors. This predictive modeling framework not only validated experimental findings but also demonstrated its potential for minimizing trial-and-error in process optimization. By highlighting comparative between processing cost and performance gain, and embedding predictive analytics into material design, this work offers a rigorous, scalable, and environmentally sustainable blueprint for dye removal. It establishes a decision-making basis for whether Micron-sized porous particles-sizing of plant biosorbents is scientifically and industrially justified, contributing both scientific insight and practical guidance to the field of wastewater treatment.