Rajaa Bassam

Growing concerns about environmental pollution and the sustainability of conventional nanomaterial synthesis have accelerated interest in plant-based routes for nanoparticle production. This review provides an in-depth analysis of more than 290 peer-reviewed research and review articles published between 2010 and 2025, extracted from the Web of Science and Scopus databases, on the green synthesis of metallic and metal oxide nanoparticles using plant extracts, with particular emphasis on their characterization and application in water treatment. Plant-derived phytochemicals serve as natural reducing and stabilizing agents, enabling nanoparticle formation without hazardous reagents. Key physicochemical characterization techniques, including UV–Visible spectroscopy, X-ray diffraction, Fourier Transform Infrared spectroscopy, scanning and transmission electron microscopy, and energy-dispersive X-ray analysis, are evaluated for their roles in confirming nanoparticle structure, morphology, surface chemistry, and optical behavior. The review focuses on water purification applications, highlighting adsorption and photocatalytic degradation as the most extensively investigated removal pathways. Particular attention is given to widely studied material classes such as silver, zinc oxide, titanium dioxide, and iron-based nanoparticles, which demonstrate effective removal of heavy metals, synthetic dyes, pesticides, and pharmaceutical residues. Current limitations related to synthesis reproducibility, mechanistic understanding, stability, and scalability are critically discussed. The review concludes by identifying priority research directions, including standardized synthesis protocols, deeper chemical analysis of plant extracts, and the integration of green nanoparticles into immobilized and membrane-based systems to advance their practical implementation in sustainable water treatment technologies.

Leachate accumulation is a major concern for municipal solid waste (MSW) landfills as it causes potential harm to public health and poses a significant threat to surface water and local groundwater systems. This article presents the results of analyses on malodorous treatment at the solid waste landfill located in Casablanca, Morocco, using bio-deodorization as a pre-treatment technology. The main goal of this study is to remove odorous gases from landfill leachate. Microbial strains of Bacillus and Pseudomonas were seeded in a leachate pond to treat the odorous emissions from landfill leachate and consequently improve environmental quality and human health. After 28 days of seeding, the results showed that the addition of Bacillus and Pseudomonas greatly reduced the concentration of chemical oxygen demand (COD), biological oxygen demand (BOD5) and the ionic concentration of NH4+ to approximately 27.928 mg/L, 11550.3 mg/L and 1533 mg/L, respectively, with lower energy consumption, resulting in an average overall operational cost of 53.97 USD/m3. In addition, a significant reduction in total nitrogen (32.80%), nitrites (NO2–) (99.82%), nitrates (NO3–) (46.81%) and total phosphorus (49.50%) concentrations was also achieved at a post-treatment environmental pH of 8.5. These findings extend the field of application of biological deodorization and provide new insights into malodorous treatment methods.

In this study, a new reactor was carried out to recover UV solar radiation to degrade the methylene blue (MB) and methyl orange (MO) dyes using the raw phosphate doped by TiO₂. The raw phosphate (Pht), TiO₂, and TiO₂/doped phosphate (TiO₂/Pht) were characterized by several techniques to determine their physicochemical properties. The performance of MB and MO photocatalytic degradation was very high around 88% for MO and 99% for MB using 1 g of TiO₂/Pht at midday. This new process is capable of degrading the high concentrations of dyes in water, especially the azo dyes which are hard to treat.

Heavy metals are the most dangerous inorganic pollutants Due to their bioaccumulation and their nonbiodegradability, for this, several studies have focused on the recovery of these metals from water using different techniques. In this context, our study consists of evaluating an efficient and eco-friendly pathway of competitive recovery of heavy metals (Cd, Cr and As) from aqueous solutions by adsorption using raw rock. This adsorbent was characterized before and after the adsorption process by several techniques. The multi-metals adsorption process in the batch mode was undertaken to evaluate the effect of adsorbent mass, contact time, pH, Temperature, and initial heavy metals concentration. The kinetic data were analyzed using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic models. According to the modeling of the experimental results, the adsorption kinetics of heavy metals were adapted to the pseudo-second-order model. The adsorption isotherms were evaluated by the Langmuir and Freundlich isotherm models. The experimental isotherm data of heavy metals were better fitted with the Langmuir model rather than Freundlich isotherm models. The maximum experimental adsorption capacities (Q_max) predicted by the Langmuir model are 15.23 mg/g for Cd (II), 17.54 mg/g for Cr (VI) and 16.36 mg/g for As (III). The values of thermodynamic parameters revealed that the heavy metals adsorption was exothermic, favorable, and spontaneous in nature. The desorption process of heavy metals showed that this raw rock had excellent recycling capacity. Based on the results, these untreated clays can be used as inexpensive and environmentally friendly adsorbents to treat water contaminated by heavy metals.

The aim of this study is the valorization of the Moroccan clays (QC-MC and QC-MT) from the Middle Atlas region as adsorbents for the treatment of water contaminated by cadmium Cd (II) ions. The physicochemical properties of natural clays are characterized by ICP-MS, XRD, FTIR, and SEM techniques. The adsorption process is investigated as a function of adsorbent mass, solution pH, contact time, temperature, and initial Cd (II) ion concentration. The kinetic investigation shows that the adsorption equilibrium of Cd (II) ions by both natural clays is reached after 30 min for QC-MT and 45 min for QC-MC and fits well to a pseudo-second-order kinetic model. The isotherm study is best fitted by a Freundlich model, with the maximum adsorption capacity determined by the linear form of the Freundlich isotherm being 4.23 mg/g for QC-MC and 5.85 mg/g for QC-MT at 25°C. The cadmium adsorption process was thermodynamically spontaneous and exothermic. The regeneration process showed that these natural clays had excellent recycling capacity. Characterization of the Moroccan natural clays before and after the adsorption process through FTIR, SEM, XRD, and EDX techniques confirmed the Cd (II) ion adsorption on the surfaces of both natural clay adsorbents. Overall, the high adsorption capacity of both natural clays for Cd (II) ions removal compared to other adsorbents motioned in the literature indicated that these two natural adsorbents are excellent candidates for heavy metal removal from aqueous environments.