Zineb Kassab

The widespread presence of diclofenac (DCF) in wastewater poses significant environmental and health risks, requiring advanced treatment strategies that go beyond conventional methods.

The advancement of sustainable carbon materials necessitates the implementation of scalable and environmentally benign processing methodologies that circumvent energy-intensive graphitization and the utilization of fossil-derived precursors.

The objective of this research is to develop environmentally friendly, risk-free and effective adsorbent composite beads that remove Cu(II) ions from aqueous solutions using cost-effective biopolymers (Carboxymethylcellulose (CMC) and sodium alginate (AL)). The synthesized hydrogel beads (AL@CMC) were dried using two drying modes, namely air-drying and freeze-drying, and characterized using scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Brunauer–Emmett–Teller (BET) analysis. The study investigated factors such as pH, adsorbent dosage, reaction time, Cu(II) ions concentration, and temperature to elucidate the adsorption mechanisms involved in removing copper ions. The results indicated that the hydrogel exhibited a maximum adsorption capacity of 99.05 mg·g⁻¹, which is highly competitive compared to previous studies; the AL@CMC beads prepared in this work show a significantly higher adsorption capacity, improved stability due to the interpenetrated biopolymer network, and a clear enhancement from freeze-drying, which greatly increases porosity and active surface area. In addition, the pseudo-second-order nonlinear kinetic model best described the experimental data, implying the chemical nature of the adsorption process. Furthermore, the thermodynamic studies revealed that the adsorption process was endothermic, spontaneous, and homogenous. A Monte Carlo simulation model was utilized to ensure compatibility with the adsorption mechanism, in order to delve deeper into the intricacies of the adsorption process and gain a more comprehensive understanding of its underlying mechanisms and behavior. In conclusion, the prepared hydrogel beads proved to be an effective adsorbent for efficiently removing copper ions, making them a promising solution for addressing Cu(II) ion pollution.

In the current work, a novel carbonaceous composite was successfully synthesized via pyrolysis utilizing lignin extracted from Raw Stipa Tenacissima fibers, locally referred to as Alfa fibers, combined with clay. This composite material was developed with the aim of enhancing the removal efficiency of anionic dyes from wastewater, particularly methyl orange (MO), which is commonly used in the textile industry and known for its persistence in aquatic environments. A comprehensive physicochemical characterization of the adsorbent was conducted to know its surface and structural properties. Zeta potential analysis provided insight into the surface charge behavior, The Brunauer-Emmett-Teller method revealed a significant increase in specific surface area postcarbonization, which correlates with improved adsorption performance. The successful incorporation of carbon on the clay surface was further confirmed by EDX mapping, indicating a uniform and stable distribution of carbonaceous matter throughout the composite matrix. The adsorption performance of the material was evaluated through batch adsorption experiments. Key operational parameters such as adsorbent dosage, contact time, initial dye concentration, temperature, and pH were optimized to identify the conditions leading to maximum removal efficiency. Kinetic modeling indicated that the adsorption behavior closely followed the pseudo-first-order model, suggesting that the process is governed by physisorption mechanisms. A remarkable improvement in adsorption capacity was observed upon carbonization, with the composite exhibiting a maximum equilibrium adsorption capacity (Q_e) of 228.58 mg/g, compared to 110.07 mg/g for pristine clay. To gain molecular-level insights into the adsorption mechanism, density functional theory calculations and Monte Carlo simulations were employed. These theoretical investigations revealed stronger binding affinities of MO molecules on the composite surface, primarily driven by electrostatic interactions and hydrogen bonding between the dye molecules and the surface functional groups introduced during carbonization.