Browsing by Author "Ouazene, Naima"

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Equilibrium and Kinetic Modelling of Astrazon Yellow Adsorption by Sawdust: Effect of Important Parameters
(2010) Ouazene, Naima; Sahmoune, Mohamed Nasser
This paper aims to investigate the sorption of Astrazon yellow (A.Y.) onto sawdust (Aleppo pine tree), a forest waste as that acts as a low-cost adsorbent. In our experiments, the batch sorption is studied with respect to solute concentration, contact time, adsorbent dose, particle size and pH. The adsorption process attains equilibrium within 300 minutes. The extent of dye removal decreased with increasing particle size and increased with increasing contact time, adsorbent dose and pH. The equilibrium data were analysed by the Langmuir and Freundlich isotherms. The characteristic parameters for each isotherm were determined. By considering the experimental results and adsorption models applied in this study, it can be concluded that equilibrium data were represented well by the Langmuir isotherm equation. Maximum adsorption capacity calculated at 293K was 81.8 mg/g. Five kinetic models (pseudo-first order, pseudo-second order, fractional power, Elovich and intraparticle diffusion kinetic equations) were used to predict the adsorption rate constants. The kinetics of adsorption of the basic dye followed both Elovich and pseudo-second order kinetics, and intraparticle diffusion was not the sole rate-controlling step. The effective diffusion of Astrazon yellow in sawdust according to Boyd Model was 24.22 .10􀀀12 m2/S. In order to reveal the adsorption characteristic of sawdust samples, SEM and FTIR spectra analyses were carried out. The results show that sawdust (Aleppo pine tree) can be an alternative low-cost adsorbent for removing cationic dyes from wastewater.
Machine learning algorithms prediction of methyl orange removal by Fenton oxidation process
(Springer Science and Business Media, 2025) Ouazene, Naima; Harrar, Khaled; Gharbi, Amine; Zahi, Salah Eddine; Mokrane, Said; Mokrane, Hind
Fenton oxidation, an advanced oxidation process (AOP), effectively mineralizes azo dyes, mitigating their environmental impact. The Fenton oxidation process (Fe2⁺/H₂O₂) was employed for the degradation of methyl orange (MO) under varying operational conditions, with its efficiency assessed through chemical oxygen demand (COD) analysis. This study aims to develop predictive models for MO degradation efficiency using four machine learning (ML) algorithms: Gaussian process regression (GPR), multilayer perceptron (MLP), decision tree (DT), and support vector regression (SVR). These models were developed and validated using 42 experimental data points obtained under controlled conditions. Experimental findings revealed a 99% COD removal at an initial MO concentration of 125 mg/L, optimized at pH 3.5, [Fe2⁺] = 25 mg/L, reaction time = 90 min, and a molar ratio of [H₂O₂]/[MO] = 42.5. The predictive accuracy of the ML models was evaluated using the coefficient of determination (R2) and root mean square error (RMSE). The GPR model demonstrated the highest predictive performance (R2 = 0.970), followed by DT (R2 = 0.964). The MLP and SVM models exhibited slightly lower predictive capacities, with R2 values of 0.946 and 0.910, respectively. Feature importance analysis indicated that reaction time was the most significant parameter influencing COD removal, underscoring the necessity of its optimization in practical applications. The integration of ML-based predictive modeling with AOPs provides a robust approach for enhancing wastewater treatment efficiency. The outcomes of this study hold particular relevance for water reuse applications in arid and semiarid regions, where effective pollutant removal is critical for sustainable water resource management
Mass-transfer processes in the adsorption of cationic dye by sawdust
(Wiley, 2012) Sahmoune, Mohamed Nasser; Ouazene, Naima
Adsorption kinetic and equilibrium studies of cationic dye namely, Astrazon Yellow (AY) from aqueous solution at various initial dye concentration (15–50 mg/l), pH (2–9), particle size <1600 μm on Aleppo pine-tree sawdust were studied in a batch mode operation. Batch studies revealed that the potential of Aleppo pine-tree sawdust in dye removal was dependant on initial pH and initial dye concentration. In order to select the main rate-limiting step in the overall uptake mechanism, a single external mass transfer diffusion model, Urano and Tachikawa model and intraparticle diffusion model were used. The external mass transfer rate constant β was found to be 8.5 10-5 m-1 at initial concentration 50 mg/l of AY and 1.14 10-4 m-1 at initial concentration 15 mg/l of AY. It was observed multi-linearity in the shape of the intraparticle diffusion plot. The two phases in the intraparticle diffusion plot suggest that the sorption process proceeds by surface sorption and an intraparticle diffusion stage. The effective diffusion coefficients Di were found to be 3.88 10-11 cm2/s and 4.2 10-11 cm2/s for initial concentration of AY of 15 mg/l and 50 mg/l respectively, indicating a poor intraparticle diffusion into Aleppo pine-tree sawdust . AY sorption onto sawdust was mainly located on the surface. The equilibrium isotherms were analysed using the Langmuir, Freundlich, Temkin and Elovich models. It was seen that the sorption data fitted to Langmuir, Freundlich, Temkin and the Elovich isotherms, but they were very well described by the Langmuir model.
Medicinal product (Paracetamol) removal by adsorption in aqueous solution; Investigation of kinetic parameters, equilibrium and mass transfer
(Technology Publishing Group, 2022) Ouazene, Naima; Belhaneche-Bensemra, N.; Khelifi, A.; Benbatta, A.
The adsorption behavior of the medicinal product, paracetamol, using commercial activated carbon in aqueous solution was investigated. In this work, the study of equilibrium, kinetics as well as the idenorder kinetics with R2 = 0.99 for the three studied concentrations. Two mathematical models were tested in order to determine the limiting step of the mass transfer of the paracetification of the mass transfer stages that occur in adsorption were carried out.It was found that the appropriate isotherm model for the equilibrium process was the Langmuir, and the monolayer adsorption capacity was found to be 104.17mg.g-1 at 298 K. The result of the adsorption kinetics shows that the adsorption maximum was reached at 60 min and follows the linear form of the pseudo second tamol adsorption process onto activated carbon. The results showed that the adsorption process was governed by external diffusion