souad djerad | Badji Mokhtar - Annaba University (original) (raw)

Papers by souad djerad

Transition Metal Chemistry, 2024

Nanocrystalline (CoMn) 50 Ni 50 powders were prepared by the mechanical alloying process in a hig... more Nanocrystalline (CoMn) 50 Ni 50 powders were prepared by the mechanical alloying process in a high-energy planetary ball mill under an argon atmosphere. Morphology, structure, microstructure, and magnetic properties were investigated using scanning electron microscopy, X-ray diffraction, and magnetometry. The (CoMn) 50 Ni 50 powders exhibit a highly disordered solid solution with a lattice parameter of a = 0.3542(4) nm, and undergo a ferromagnetic to paramagnetic transition at a Curie temperature of about 700 K. Different magnetic parameters were extracted from the approach to magnetic saturation. The electronic structure of the ferromagnetic powders was performed by the self-consistent ab initio calculations based on the Korringa-Kohn-Rostocker (KKR) method combined with the Coherent Potential Approximation (CPA). The total DOS is mainly due to the 3d-like states of the constituent elements Co, Mn, and Ni. The powders were tested in the discoloration reaction of Methylene Blue under different operation conditions via a heterogeneous Fenton-like process.

Industrial & Engineering Chemistry Research, Jun 22, 2010

ABSTRACT In this study, the dissolution of CoO from CoO/Al2O3 catalyst with HCl, H2SO4, and HNO3 ... more ABSTRACT In this study, the dissolution of CoO from CoO/Al2O3 catalyst with HCl, H2SO4, and HNO3 solutions was investigated in a batch reactor employing parameters that were expected to affect the dissolution rate of cobalt, such as stirring speed, temperature, and acid concentration. It was found that 99.82% of cobalt was dissolved after 4 h with HCl at 2 M, 75 °C, and a liquid-to-solid ratio (l/s) of 100 mL/g, while only 31.96% and 13.57% cobalt dissolutions were reached with H2SO4 and HNO3, respectively, under the same operation conditions. The difference in dissolution rates was due to the presence of different anions (Cl−, NO3−, and HSO4−) involved in the surface reactions. Dissolution kinetic of cobalt was examined according to a heterogeneous model. It was found that the dissolution rate was controlled by surface chemical processes in all cases.

DESALINATION AND WATER TREATMENT

In this study, the complexity of sodium ascorbate as a reducing reagent for copper by executing r... more In this study, the complexity of sodium ascorbate as a reducing reagent for copper by executing reactions with different ascorbate concentrations at 30°C and a copper concentration at 5 mM was emphasized. It was found that increasing the molar ratio of n ascorbate /n Cu2+ from 1:1 to 10:1 prolonged the time for the completion of the reduction from 30 to 300 min, respectively. The reactions were investigated by the cyclic voltammetry method and the products were characterized by scanning electron microscopy and X-ray diffraction analyses. The synthesized materials obtained with molar ratios of 1:1 and 10:1 were composed of 55.47% Cu + 44.53% Cu 2 O (labeled as As1) and 73.66% Cu + 26.34% Cu 2 O (labeled as As10), respectively. Both products were tested for their ability to discolor Basic Red 29 via the Fenton reaction. The discoloration of the dye was more rapid with As1, due to the higher Cu 2 O content.

Rev. Sci. Technol., Synthèse, 2022

Dans ce travail, une poudre de cuivre a été synthétisée avec une méthode écocompatible basée sur... more Dans ce travail, une poudre de cuivre a été synthétisée avec une méthode écocompatible basée sur la réduction d’une solution de sulfate de cuivre avec
l’ascorbate de sodium (vitamine C). La poudre obtenue est composée
majoritairement de cuivre métallique (Cu) avec la présence mineure de cuprite
(Cu2O). Le produit obtenu a été utilisé pour générer in-situ H2O2/
•OH via une
réaction d’oxydo-réduction se produisant en milieu aqueux acide entre le
cuivre et l’oxygène dissout dans l’eau. Le cuivre a été utilisé dans une réaction
de décoloration du méthyl orange (MO). Les résultats ont montré que
l’utilisation 30 mg du cuivre à 60 °C a totalement décoloré le MO au bout de
90 min. L’application des ultrasons à 40 kHz et l’ajout de H2O2 à 6 mM à
fortement réduit le temps pour la décoloration totale à 6 min

physica status solidi (a)

Desalination and Water Treatment, 2011

An experimental study is presented on facilitated transport of copper (II) cations through a bulk... more An experimental study is presented on facilitated transport of copper (II) cations through a bulk liquid membrane containing di(2-ethylhexyl) phosphoric acid (D2EHPA) in dichloromethane. The effects of different parameters on copper transport through the membrane such as the carrier concentration, pH of the product and feed phases, stirring speed and temperature were investigated. It was found that copper transport was greatly affected by stirring speed and the pH of both aqueous phases, while temperature influenced weakly the copper transport. The extraction of copper from ammoniacal solution was very fast reaching 100% after just 1 h while only 2% of copper remained into the membrane at the end of the operation.

Canadian Journal of Chemistry

A two-level full factorial design with interactions effectively used to screen for parameters imp... more A two-level full factorial design with interactions effectively used to screen for parameters impacting the degradation of Direct Red 89 (DR 89) by thermally activated persulfate. Four variables were identified as critical: reaction temperature (T), persulfate concentration ([PS]), initial pH of medium (pH) and initial DR 89 concentration ([DR89]i). The fit goodness of the reduced model tested by performing plots of descriptive statistic, residuals versus predicted responses, normal probability versus residuals and observed versus predicted values, as well as examining the ANOVA table. The observed and the predicted response values of the reduced model exhibited a good correlation, with R2, R2adj, Q2 and ‘p’ of 0.990, 0.983, 0.968 and 0.000, respectively. To determine optimal operating parameters, the desirability function utilized, and it determined to be 0.988 with a predicted response of 99.89% for an initial DR 89 concentration of 51.96 mg/L, a persulfate concentration of 12 mM,...

Environmental Research and Technology, 2020

Copper(II) ions (Cu 2+) in copper sulfate solutions (CuSO4) can be reduced with several carbohydr... more Copper(II) ions (Cu 2+) in copper sulfate solutions (CuSO4) can be reduced with several carbohydrates to produce copper metal powder. In this study glucose was used as a reducing agent. The big challenge in this study was to find the optimum conditions for copper ions reduction because they were entwined with positive conditions for degradation and hydrolyses of sugar (D-glucose). For that reason, the impact of several parameters on these conditions was investigated in a series of experiments in this research study. The glucose concentration (0.2-1.6M), the temperature (30-70 °C), initial sodium hydroxide concentration (0.2-0.4M), the role of adding sulfuric acid (H2SO4) at different volumes (0.6-3 mL) and the addition of ascorbic acid at different doses (4-20 mL) were the considered key parameters that were studied in this research. The synthesis of copper was restricted due to organic acid build up and reactions of the degradation products and copper. Under optimum conditions using glucose as a reducing agent, maximum of 48% of copper ions were transformed to copper metal (Cu). By adding ascorbic acid at the end of the experiment process, reduction efficiency was 100% where total and complete copper reduction was achievable. Most of solid particles were analyzed and the characterization and nature of the produced solid was achieved by X-Ray Diffraction.

The catalytic reduction of NO x under different oxygen concentrations leading to different NO/NO ... more The catalytic reduction of NO x under different oxygen concentrations leading to different NO/NO 2 compositions has been studied in the presence of V3W9Ti and V8W9Ti catalysts in a tubular flow reactor. The results have shown that increasing O 2 concentration leads to increase the NO x reduction in low temperature range [150-275 °C]. Slight effect of O 2 concentration on NO x conversion was observed at higher temperatures. SCR reaction also occurred in the absence of gaseous oxygen but with low NO conversion indicating the strong redox properties of both catalysts. Aged catalysts exhibited relative good activities in NO x reduction. This is probably due to the sol gel method used for the preparation of the catalysts known to improve the catalysts properties.

In this study, the leaching of NiO from NiO/α-Al2O3 catalyst in acidic (HCl, HNO3 and H2SO4) and ... more In this study, the leaching of NiO from NiO/α-Al2O3 catalyst in acidic (HCl, HNO3 and H2SO4) and ammoniacal ((NH4)2CO3 and CH3COONH4) media was investigated. The effects of leachant concentration, liquid/solid ratio, stirring speed and temperature were studied. It was found that 100% of nickel was dissolved after 30 min of reaction with HCl at 2M, 80°C and liquid/solid ratio of 50 mL/g, while HNO3 and H2SO4 dissolved 77.15 and 46.12%, respectively, under the same operation conditions. Mixing two strong acids led to a synergetic effect on nickel leaching at the beginning of the reactions followed by a rapid stabilization in dissolution. Ammoniacal leaching was less efficient than acidic one registering 41.43% with ammonium carbonate and 29.16% with ammonium acetate after 180 min. However, the addition of chloride to ammonium carbonate led to totally dissolve NiO. © 2017 Process Engineering Journal.

Environmental Research and Technology, 2020

Development of enhanced methods for copper particles synthesis is crucial for the improvement of ... more Development of enhanced methods for copper particles synthesis is crucial for the improvement of material science and technology. Therefore, in this study a successful synthesis of copper metal was achieved by chemical reduction. Ascorbic acid was used as a reducing agent. In the presence of soda, copper sulphate pentahydrated (CuSO4, 5H2O) with acid ascorbic at 60 °C of temperature produced metallic copper powder with the total degradation (100%) of copper ions (Cu 2+). The presence of hydroxide ions (OH-) is necessary to achieve and improve the chemical reduction reaction. Several parameters, as reducing agent volume, reaction temperature and soda quantity were investigated and checked their impact in this research study. The obtained powder was washed and dried in the fresh air then analysed by X-ray diffraction.

Journal of the Iranian Chemical Society, 2020

MATTER: International Journal of Science and Technology, 2017

Industrial & Engineering Chemistry Research, 2010

Desalination, 2008

The discharge of heavy metals into the environment is a serious problem facing numerous industrie... more The discharge of heavy metals into the environment is a serious problem facing numerous industries. Heavy metals tend to accumulate in living organisms causing various diseases and disorders. So the search for extraction techniques to remove those heavy metals are of increasing interest. Liquid membranes have shown great potential in this way, especially in cases where metal concentrations are relatively low and other techniques cannot be applied efficiently. A comparative kinetic study of the facilitated counter transport of copper ion through bulk liquid membranes containing D2EHPA, CYANEX 272 and LIX 984N as carriers and protons as counter ions is carried out is this paper. The transport kinetic was analysed by means of a kinetic model involving two consecutive irreversible first-order reactions. The rate constants of the extraction and stripping reactions and the maximum transport fluxes of copper(II) through the bulk liquid membrane were determined for the three carriers.

Corrosion Science, 2014

The processes of aluminum degradation in HCl, H 2 SO 4 , HNO 3 and NaOH solutions were investigat... more The processes of aluminum degradation in HCl, H 2 SO 4 , HNO 3 and NaOH solutions were investigated in static and agitated media. The effects of concentration, temperature, and mixture of acids were studied. The dissolution of aluminum was faster in NaOH and HCl than in H 2 SO 4 and HNO 3. The activation energies were 86.5 and 52.4 kJ/mol for Al dissolved in HCl and NaOH respectively. An inhibiting effect on Al dissolution was observed with the mixture HCl + HNO 3 regardless of the conditions used while a synergetic effect was observed with the mixture H 2 SO 4 + HCl using acids at 4 M.

Chemical Engineering Journal, 2009

Catalysis Communications, 2009

The present paper presents a simple method for the reliable preparation of nano-scaled ZrO 2. In ... more The present paper presents a simple method for the reliable preparation of nano-scaled ZrO 2. In this wet synthesis, a stable Zr sol is produced by using a mixture of Zr(OC 3 H 7) 4 , HNO 3 and H 2 O. Precipitation is firstly achieved when ammoniac conditions are adjusted. Zirconia is formed by annealing the gel-like product at 200°C resulting in agglomerated particles. De-agglomeration is simply achieved by ultrasonic exposure leading to particles of about 60 nm revealing a BET surface area of 150 m 2 /g. The beneficial effect of this nano-sized material as compared to bulk ZrO 2 is shown in SCR using corresponding Fe 2 O 3 /ZrO 2 patterns.

Lebanese Science Journal, 2008

Reactivity of Cu2O-Cu in the Discoloration of Methylene Blue via a Heterogeneous Fenton-Like Process, 2021

In this study, copper particles were synthesized by using sodium ascorbate as a green reducing ag... more In this study, copper particles were synthesized by using sodium ascorbate as a green reducing agent under atmospheric conditions. The product was micron-sized and mainly formed by metallic copper Cu with a minor presence of Cu2O. The product was used as a catalyst in the discoloration of methylene blue in a heterogeneous Fenton-like process in which H2O2 was produced in situ. The effect of different parameters such as copper loading, dye concentration, pH of the solution, and the temperature was studied. The total discoloration was achieved after 42 min with 30 mg of copper at 60 °C and pH= 3. The amount of H2O2 produced in situ during methylene blue discoloration was evidenced by the permanganate method. It was found the formation of 110 µM after 40 min. The external addition of H2O2 at 0.001 M reduced the time for total discoloration to 10 min and the application of 40 kHz ultrasounds reduced the time further to 6 min.

Transition Metal Chemistry, 2024

Nanocrystalline (CoMn) 50 Ni 50 powders were prepared by the mechanical alloying process in a hig... more Nanocrystalline (CoMn) 50 Ni 50 powders were prepared by the mechanical alloying process in a high-energy planetary ball mill under an argon atmosphere. Morphology, structure, microstructure, and magnetic properties were investigated using scanning electron microscopy, X-ray diffraction, and magnetometry. The (CoMn) 50 Ni 50 powders exhibit a highly disordered solid solution with a lattice parameter of a = 0.3542(4) nm, and undergo a ferromagnetic to paramagnetic transition at a Curie temperature of about 700 K. Different magnetic parameters were extracted from the approach to magnetic saturation. The electronic structure of the ferromagnetic powders was performed by the self-consistent ab initio calculations based on the Korringa-Kohn-Rostocker (KKR) method combined with the Coherent Potential Approximation (CPA). The total DOS is mainly due to the 3d-like states of the constituent elements Co, Mn, and Ni. The powders were tested in the discoloration reaction of Methylene Blue under different operation conditions via a heterogeneous Fenton-like process.

Industrial & Engineering Chemistry Research, Jun 22, 2010

ABSTRACT In this study, the dissolution of CoO from CoO/Al2O3 catalyst with HCl, H2SO4, and HNO3 ... more ABSTRACT In this study, the dissolution of CoO from CoO/Al2O3 catalyst with HCl, H2SO4, and HNO3 solutions was investigated in a batch reactor employing parameters that were expected to affect the dissolution rate of cobalt, such as stirring speed, temperature, and acid concentration. It was found that 99.82% of cobalt was dissolved after 4 h with HCl at 2 M, 75 °C, and a liquid-to-solid ratio (l/s) of 100 mL/g, while only 31.96% and 13.57% cobalt dissolutions were reached with H2SO4 and HNO3, respectively, under the same operation conditions. The difference in dissolution rates was due to the presence of different anions (Cl−, NO3−, and HSO4−) involved in the surface reactions. Dissolution kinetic of cobalt was examined according to a heterogeneous model. It was found that the dissolution rate was controlled by surface chemical processes in all cases.

DESALINATION AND WATER TREATMENT

In this study, the complexity of sodium ascorbate as a reducing reagent for copper by executing r... more In this study, the complexity of sodium ascorbate as a reducing reagent for copper by executing reactions with different ascorbate concentrations at 30°C and a copper concentration at 5 mM was emphasized. It was found that increasing the molar ratio of n ascorbate /n Cu2+ from 1:1 to 10:1 prolonged the time for the completion of the reduction from 30 to 300 min, respectively. The reactions were investigated by the cyclic voltammetry method and the products were characterized by scanning electron microscopy and X-ray diffraction analyses. The synthesized materials obtained with molar ratios of 1:1 and 10:1 were composed of 55.47% Cu + 44.53% Cu 2 O (labeled as As1) and 73.66% Cu + 26.34% Cu 2 O (labeled as As10), respectively. Both products were tested for their ability to discolor Basic Red 29 via the Fenton reaction. The discoloration of the dye was more rapid with As1, due to the higher Cu 2 O content.

Rev. Sci. Technol., Synthèse, 2022

Dans ce travail, une poudre de cuivre a été synthétisée avec une méthode écocompatible basée sur... more Dans ce travail, une poudre de cuivre a été synthétisée avec une méthode écocompatible basée sur la réduction d’une solution de sulfate de cuivre avec
l’ascorbate de sodium (vitamine C). La poudre obtenue est composée
majoritairement de cuivre métallique (Cu) avec la présence mineure de cuprite
(Cu2O). Le produit obtenu a été utilisé pour générer in-situ H2O2/
•OH via une
réaction d’oxydo-réduction se produisant en milieu aqueux acide entre le
cuivre et l’oxygène dissout dans l’eau. Le cuivre a été utilisé dans une réaction
de décoloration du méthyl orange (MO). Les résultats ont montré que
l’utilisation 30 mg du cuivre à 60 °C a totalement décoloré le MO au bout de
90 min. L’application des ultrasons à 40 kHz et l’ajout de H2O2 à 6 mM à
fortement réduit le temps pour la décoloration totale à 6 min

physica status solidi (a)

Desalination and Water Treatment, 2011

An experimental study is presented on facilitated transport of copper (II) cations through a bulk... more An experimental study is presented on facilitated transport of copper (II) cations through a bulk liquid membrane containing di(2-ethylhexyl) phosphoric acid (D2EHPA) in dichloromethane. The effects of different parameters on copper transport through the membrane such as the carrier concentration, pH of the product and feed phases, stirring speed and temperature were investigated. It was found that copper transport was greatly affected by stirring speed and the pH of both aqueous phases, while temperature influenced weakly the copper transport. The extraction of copper from ammoniacal solution was very fast reaching 100% after just 1 h while only 2% of copper remained into the membrane at the end of the operation.

Canadian Journal of Chemistry

A two-level full factorial design with interactions effectively used to screen for parameters imp... more A two-level full factorial design with interactions effectively used to screen for parameters impacting the degradation of Direct Red 89 (DR 89) by thermally activated persulfate. Four variables were identified as critical: reaction temperature (T), persulfate concentration ([PS]), initial pH of medium (pH) and initial DR 89 concentration ([DR89]i). The fit goodness of the reduced model tested by performing plots of descriptive statistic, residuals versus predicted responses, normal probability versus residuals and observed versus predicted values, as well as examining the ANOVA table. The observed and the predicted response values of the reduced model exhibited a good correlation, with R2, R2adj, Q2 and ‘p’ of 0.990, 0.983, 0.968 and 0.000, respectively. To determine optimal operating parameters, the desirability function utilized, and it determined to be 0.988 with a predicted response of 99.89% for an initial DR 89 concentration of 51.96 mg/L, a persulfate concentration of 12 mM,...

Environmental Research and Technology, 2020

Copper(II) ions (Cu 2+) in copper sulfate solutions (CuSO4) can be reduced with several carbohydr... more Copper(II) ions (Cu 2+) in copper sulfate solutions (CuSO4) can be reduced with several carbohydrates to produce copper metal powder. In this study glucose was used as a reducing agent. The big challenge in this study was to find the optimum conditions for copper ions reduction because they were entwined with positive conditions for degradation and hydrolyses of sugar (D-glucose). For that reason, the impact of several parameters on these conditions was investigated in a series of experiments in this research study. The glucose concentration (0.2-1.6M), the temperature (30-70 °C), initial sodium hydroxide concentration (0.2-0.4M), the role of adding sulfuric acid (H2SO4) at different volumes (0.6-3 mL) and the addition of ascorbic acid at different doses (4-20 mL) were the considered key parameters that were studied in this research. The synthesis of copper was restricted due to organic acid build up and reactions of the degradation products and copper. Under optimum conditions using glucose as a reducing agent, maximum of 48% of copper ions were transformed to copper metal (Cu). By adding ascorbic acid at the end of the experiment process, reduction efficiency was 100% where total and complete copper reduction was achievable. Most of solid particles were analyzed and the characterization and nature of the produced solid was achieved by X-Ray Diffraction.

The catalytic reduction of NO x under different oxygen concentrations leading to different NO/NO ... more The catalytic reduction of NO x under different oxygen concentrations leading to different NO/NO 2 compositions has been studied in the presence of V3W9Ti and V8W9Ti catalysts in a tubular flow reactor. The results have shown that increasing O 2 concentration leads to increase the NO x reduction in low temperature range [150-275 °C]. Slight effect of O 2 concentration on NO x conversion was observed at higher temperatures. SCR reaction also occurred in the absence of gaseous oxygen but with low NO conversion indicating the strong redox properties of both catalysts. Aged catalysts exhibited relative good activities in NO x reduction. This is probably due to the sol gel method used for the preparation of the catalysts known to improve the catalysts properties.

In this study, the leaching of NiO from NiO/α-Al2O3 catalyst in acidic (HCl, HNO3 and H2SO4) and ... more In this study, the leaching of NiO from NiO/α-Al2O3 catalyst in acidic (HCl, HNO3 and H2SO4) and ammoniacal ((NH4)2CO3 and CH3COONH4) media was investigated. The effects of leachant concentration, liquid/solid ratio, stirring speed and temperature were studied. It was found that 100% of nickel was dissolved after 30 min of reaction with HCl at 2M, 80°C and liquid/solid ratio of 50 mL/g, while HNO3 and H2SO4 dissolved 77.15 and 46.12%, respectively, under the same operation conditions. Mixing two strong acids led to a synergetic effect on nickel leaching at the beginning of the reactions followed by a rapid stabilization in dissolution. Ammoniacal leaching was less efficient than acidic one registering 41.43% with ammonium carbonate and 29.16% with ammonium acetate after 180 min. However, the addition of chloride to ammonium carbonate led to totally dissolve NiO. © 2017 Process Engineering Journal.

Environmental Research and Technology, 2020

Development of enhanced methods for copper particles synthesis is crucial for the improvement of ... more Development of enhanced methods for copper particles synthesis is crucial for the improvement of material science and technology. Therefore, in this study a successful synthesis of copper metal was achieved by chemical reduction. Ascorbic acid was used as a reducing agent. In the presence of soda, copper sulphate pentahydrated (CuSO4, 5H2O) with acid ascorbic at 60 °C of temperature produced metallic copper powder with the total degradation (100%) of copper ions (Cu 2+). The presence of hydroxide ions (OH-) is necessary to achieve and improve the chemical reduction reaction. Several parameters, as reducing agent volume, reaction temperature and soda quantity were investigated and checked their impact in this research study. The obtained powder was washed and dried in the fresh air then analysed by X-ray diffraction.

Journal of the Iranian Chemical Society, 2020

MATTER: International Journal of Science and Technology, 2017

Industrial & Engineering Chemistry Research, 2010

Desalination, 2008

The discharge of heavy metals into the environment is a serious problem facing numerous industrie... more The discharge of heavy metals into the environment is a serious problem facing numerous industries. Heavy metals tend to accumulate in living organisms causing various diseases and disorders. So the search for extraction techniques to remove those heavy metals are of increasing interest. Liquid membranes have shown great potential in this way, especially in cases where metal concentrations are relatively low and other techniques cannot be applied efficiently. A comparative kinetic study of the facilitated counter transport of copper ion through bulk liquid membranes containing D2EHPA, CYANEX 272 and LIX 984N as carriers and protons as counter ions is carried out is this paper. The transport kinetic was analysed by means of a kinetic model involving two consecutive irreversible first-order reactions. The rate constants of the extraction and stripping reactions and the maximum transport fluxes of copper(II) through the bulk liquid membrane were determined for the three carriers.

Corrosion Science, 2014

The processes of aluminum degradation in HCl, H 2 SO 4 , HNO 3 and NaOH solutions were investigat... more The processes of aluminum degradation in HCl, H 2 SO 4 , HNO 3 and NaOH solutions were investigated in static and agitated media. The effects of concentration, temperature, and mixture of acids were studied. The dissolution of aluminum was faster in NaOH and HCl than in H 2 SO 4 and HNO 3. The activation energies were 86.5 and 52.4 kJ/mol for Al dissolved in HCl and NaOH respectively. An inhibiting effect on Al dissolution was observed with the mixture HCl + HNO 3 regardless of the conditions used while a synergetic effect was observed with the mixture H 2 SO 4 + HCl using acids at 4 M.

Chemical Engineering Journal, 2009

Catalysis Communications, 2009

The present paper presents a simple method for the reliable preparation of nano-scaled ZrO 2. In ... more The present paper presents a simple method for the reliable preparation of nano-scaled ZrO 2. In this wet synthesis, a stable Zr sol is produced by using a mixture of Zr(OC 3 H 7) 4 , HNO 3 and H 2 O. Precipitation is firstly achieved when ammoniac conditions are adjusted. Zirconia is formed by annealing the gel-like product at 200°C resulting in agglomerated particles. De-agglomeration is simply achieved by ultrasonic exposure leading to particles of about 60 nm revealing a BET surface area of 150 m 2 /g. The beneficial effect of this nano-sized material as compared to bulk ZrO 2 is shown in SCR using corresponding Fe 2 O 3 /ZrO 2 patterns.

Lebanese Science Journal, 2008

Reactivity of Cu2O-Cu in the Discoloration of Methylene Blue via a Heterogeneous Fenton-Like Process, 2021

In this study, copper particles were synthesized by using sodium ascorbate as a green reducing ag... more In this study, copper particles were synthesized by using sodium ascorbate as a green reducing agent under atmospheric conditions. The product was micron-sized and mainly formed by metallic copper Cu with a minor presence of Cu2O. The product was used as a catalyst in the discoloration of methylene blue in a heterogeneous Fenton-like process in which H2O2 was produced in situ. The effect of different parameters such as copper loading, dye concentration, pH of the solution, and the temperature was studied. The total discoloration was achieved after 42 min with 30 mg of copper at 60 °C and pH= 3. The amount of H2O2 produced in situ during methylene blue discoloration was evidenced by the permanganate method. It was found the formation of 110 µM after 40 min. The external addition of H2O2 at 0.001 M reduced the time for total discoloration to 10 min and the application of 40 kHz ultrasounds reduced the time further to 6 min.