Abdelmalek Chergui’s research while affiliated with Ecole Nationale Polytechnique d'Oran and other places

This work is concerned with the cyanide removal from aqueous solution by oxidation with hydrogen peroxide H2O2 catalyzed by copper zinc oxide (CuO-ZnO) nanoparticles prepared by co-precipitation method. The influences of catalyst dose, hydrogen peroxide concentration, temperature, and catalyst stability on cyanide removal were examined. The use of CuO-ZnO nanoparticles made it possible to increase the reaction rate, thus showing good catalytic activity. The cyanide removal percentage was increased after 75 minutes of reaction time from 70% to 100% by raising the catalyst dose from 0.25 g/L to 1.0 g/L. Increasing the temperature from 24 °C to 35 °C enhanced cyanide removal rate, the apparent activation energy was then found to be equal to 48 KJ/mol. The nanocatalyst was used again for four successive times and exhibited good stability. The kinetics of cyanide elimination was found to be pseudo-first order with respect to cyanide.

Cyanide compounds are widely used in some electroplating, chemical, and metallurgical industries. They are often found in their liquid discharges. This work highlights the performance of an activated alumina-supported copper catalyst in the removal of cyanide by oxidation with hydrogen peroxide in aqueous solution. The influence of catalyst dose, initial molar ratio of hydrogen peroxide/cyanides, temperature, and catalyst reuse was studied. The activated alumina-supported copper significantly enhanced the reaction rate showing a good catalytic activity. The efficiency of cyanide elimination was increased after 30 minutes of oxidation from 48% to 98% by increasing the catalyst dose from 1 to 10 g/L. Rising the temperature from 30°C to 40°C promoted cyanide removal. The catalyst can be recycled four times and show good stability. The kinetics of cyanide oxidation was revealed to be pseudo-first-order regarding cyanides. The rate constants as well as the activation energy were determined.

Aspergillus parasiticus (A. parasiticus) CBS 100926 T was used as a biosorbent for the removal of Methylene Blue (MB), Congo Red (CR), Sudan Black (SB), Malachite Green Oxalate (MGO), Basic Fuchsin (BF) and Phenol Red (PR) from aqueous solutions. The batch biosorption studies were carried out as a function of dye concentration and contact time. The biosorption process followed the pseudo-first-order and the pseudo-second-order kinetic models and the Freundlich and Langmuir isotherm models. The resulting biosorbent was characterized by Scanning Electron Microscopy (SEM), X-Ray Diffractometer and Fourier Transformer Infrared Spectroscopy (FTIR) techniques. The results of the present investigation suggest that A. parasiticus can be used as an environmentally benign and low cost biomaterial for the removal of basic and acid dyes from aqueous solution. HIGHLIGHTS • Micro-fungi Aspergillus parasiticus CBS100926T was employed as a new biosorbent for the biosorption of six dyes. • The maximum dye capacity was found to be 131.58 mg/g. • Adsorption processes can reach equilibrium within 120 min. • Adsorption processes follow the pseudo-second-order rate equation. • The results of equilibrium sorption were described through Freundlich isotherm.

Aspergillus parasiticus (A. parasiticus) CBS 100926T was used as a biosorbent for the removal of Methylene Blue (MB), Congo Red (CR), Sudan Black (SB), Malachite Green Oxalate (MGO), Basic Fuchsin (BF) and Phenol Red (PR) from aqueous solutions. The batch biosorption studies were carried out as a function of dye concentration and contact time. The biosorption process followed the pseudo-first-order and the pseudo-second-order kinetic models and the Freundlich and Langmuir isotherm models. The resulting biosorbent was characterized by Scanning Electron Microscopy (SEM), X-Ray Diffractometer and Fourier Transformer Infrared Spectroscopy (FTIR) techniques. The results of the present investigation suggest that A. parasiticus can be used as an environmentally benign and low cost biomaterial for the removal of basic and acid dyes from aqueous solution. HIGHLIGHTS Micro-fungi Aspergillus parasiticus CBS100926T was employed as a new biosorbent for the biosorption of six dyes. The maximum dye capacity was found to be 131.58 mg/g. Adsorption processes can reach equilibrium within 120 min. Adsorption processes follow the pseudo-second-order rate equation. The results of equilibrium sorption were described through Freundlich isotherm.

The present study is concerned with the valorization of date stones for the waste water treatment. Date stones as adsorbent were characterized by X-ray diffraction, FT-IR and SEM, than tested for the adsorption of Cu (II), Zn (II) and Ni (II) from aqueous solotion. The effects of different parameters on the adsorption of metal metals such as the contact time, the initial concentration and the pH of the solution were investigated. The adsorption capacity was highest at pH5. Cu (II) had higher adsorption capacity than Zn (II) and Ni (II). The equilibrium data were fitted using Freundlich and Langmuir isotherm models.

A novel approach has been tried to use both Aspergillus carbonarius (AC) and Penicillium glabrum (PG) fungi for the first time to remove methylene blue (MB) from aqueous solutions. The biosorption was favoured using a biosorbent concentration of 0.33 g/L at pH 8.2. Biosorption kinetics were evaluated for different dye concentrations (5-25 mg/L). The resulting biosorbent was characterised by scanning electron microscopy (SEM), X-ray diffractometer and Fourier transformer infrared spectroscopy (FTIR) techniques. The maximum biosorp-tion capacities of AC and PG for MB were 21.88 mg/g and 16.67 mg/g, respectively at 30°C. The results suggested that A. carbonarius and P. glabrum could be used as biosorbents for the effective removal of methylene blue from dye wastewater in terms of biosorption capacity , availability and low cost.