Radwa Elsalamony - Academia.edu (original) (raw)

Papers by Radwa Elsalamony

Journal of Environmental Chemical Engineering, 2021

Abstract This work was undertaken to provide a new potent route for wastewater treatment by devel... more Abstract This work was undertaken to provide a new potent route for wastewater treatment by developing a hybrid photocatalyst from waste rice straw. On this basis, rice straw-based SiO2 was utilized as a platform to synthesize a ternary β-Ga2O3-TiO2-SiO2 nanocomposite with type-I heterojunction band alignment using the mechanochemical method. The categorical factorial design was employed to optimize the synergistic effect between adsorption and photocatalytic performance of the nanocomposite towards removing p-nitrophenol (PNP) from wastewater under various experimental conditions. The optimization results indicated the negligible impact of catalyst dose ( X c ) and total dissolved solids ( X T D S ) on the photocatalysis with the increase of pre-adsorption time (Xads) from 60 to 180 min. In contrast, the adsorption/photocatalytic performance of ꞵ-Ga2O3-TiO2-SiO2 was found to be dependent on the solution pH ( X p H , with a percentage contribution (PC) of 26.1 %) due to its effect on the photocatalyst surface charge and the dissociation process of PNP molecules. At optimum conditions ( X c = 4.0 g/L, X p H = 6.0, X T D S = 1000 mg/L, and Xads = 180 min), the β-Ga2O3-TiO2-SiO2 exhibited high efficiency to degrade 92.4 ± 3.8 % and 68.65 ± 4.3 % of PNP (25 mg/L) after 120 min UV and visible irradiation, with kinetic rates (k) of 0.62 and 0.53 mg/(g.min), respectively. This improved performance was due to the synergism between (i) the high adsorption of PNP (k = 0.017 mg/(g.min)) on SiO2 and (ii) the effective separation of photogenerated charges between ꞵ-Ga2O3 and TiO2. The high-performance stability (up to 3 cycles) of β-Ga2O3-TiO2-SiO2 was also demonstrated towards UV/visible-induced photodegradation of organic contaminants in real petrochemical wastewater.

Journal of Water Process Engineering, 2017

A photo-catalyst of mesoporous silicate SBA-15 doped with 15%MoO 3 was synthesized by modified so... more A photo-catalyst of mesoporous silicate SBA-15 doped with 15%MoO 3 was synthesized by modified sol-gel process and then characterized by SBET, XRD, HRTEM/EDX, TGA and optical techniques. The photo-catalytic performances of 15%Mo/SBA-15 were tested in the photo-remediation of wastewater composed of multi-organic pollutants (i.e., aromatics, phenols, and dyes) at different light sources of visible (400 nm), UVB (316 nm)and UVC (254 nm) irradiation. The photo-catalytic activities of the 15%Mo/SBA-15 were considerably greater under UVC irradiation, which is coincident with 15%Mo/SBA-15 calculated band gap of 3.5 eV. Further, wastewater treatment rate was ranked in the order of aromatic > phenolic > dyes with the rate of 95%, 69%, and 14%, respectively after 120 min UVC irradiation time. A statistical analysis, using both parametric (one way ANOVA) and nonparametric (Kruskal-Wallis) methodologies, were developed to validate the experimental comparison between neat SBA-15 and 15%Mo/SBA-15 based on structural properties, light intensity and the type of organic contaminants are the key factors influencing the photo-catalytic degradation rate. The kinetic rate of the wastewater photo-catalytic remediation was found to be ranked in the order of benzene > anthracene > pyrene > naphthalene within aromatic contaminants, hydroxyphenyl ≈ chlorophenols > phenol within the phenolic group, and no significant difference between methyl orange and methyl red within dyes contaminants over 15%Mo/SBA-15. Results suggested that the developed 15%Mo/SBA-15 could be used as efficient photocatalysts for the treatment of petroleum and petrochemical wastewater with aromatic and phenolic hazardous, but not efficient for the treatment of textile wastewater pollutants.

Journal of Sol-Gel Science and Technology, 2017

A series of zinc-doped titania–silica tricomposites (Zn/xTi–SiO2) with different Ti-molar ratios ... more A series of zinc-doped titania–silica tricomposites (Zn/xTi–SiO2) with different Ti-molar ratios were prepared by sol–gel method. Zn+2 ions of 25 wt% were doped on the photo-catalysts using wet impregnation method. The as-synthesized Zn/xTi–SiO2 nano-catalysts were characterized through N2-adsorption–desorption, X-ray diffraction, transmission electron microscope, fourier transform infrared, dynamic light scatterings, photoluminescence, and diffuse reflectance techniques. Photo-catalytic degradation of phenol (PhOH) under 8-W ultraviolet C irradiation was examined. 96% removal was achieved in 150 min by using Zn/20Ti–SiO2. The kinetic study revealed that photo-degradation of PhOH follows pseudo-first order reaction mechanism, where the rate constant was 77.4 × 10−3 min−1. One-way analysis of variance, as well as Student’t-test at α = 0.05 level (95% confidence interval) was performed to comparing the means of the results obtained.Graphical Abstract

Canadian Chemical Transactions, 2014

Rice straw ash (RSA)-based composites, containing titania (TiO 2 , 50%) or copper phthalocyanine ... more Rice straw ash (RSA)-based composites, containing titania (TiO 2 , 50%) or copper phthalocyanine complex (CuPc, 1.0%) or TiO 2-CuPc combination, were prepared in disc-shaped forms. Mechano-mixing of TiO 2 could develop the mesoporous nature of the composites. TiO 2 existed as nanoparticles of average sizes in the range, 16-20 nm, homogeneously dispersed on the surface of the ash matrix. Compression of the solids using polymer binder led to only a small decrease in surface parameters, pore dimensions and average size of contained silica nanocrystallites. The composites discs were applied in the adsorption and photo-catalytic degradation (using visible light) of methylene blue (MB) dye, at ambient temperature and neutral pH. The rate of adsorption of MB on the studied composites deceased, according to the second order kinetic model, in the order: RSA-TiO 2-CuPc > RSA-TiO 2 > RSA > RSA-CuPc. TiO 2 or TiO 2-CuPc combination enhanced the rate of MB adsorption due to development of the composite surface characteristics. The rate of visible-photodegradation of MB, in terms of the first order kinetic model, deceased in the order: RSA ≈ RSA-TiO 2 > RSA-CuPc > RSA-TiO 2-CuPc. TiO 2 , by generated hydroxyl radicals (. OH) and superoxide radicals (. O 2-) and CuPc complex, by generated singlet oxygen (1 O 2) through photosensitization role, could activate the rice straw ash toward the MB photo-degradation in aqueous solutions. Some retardation in photocatalytic degradation rate observed in presence of hybrids derived from CuPc and TiO 2 was attributed to probable recombination of most of electrons donated by the bound CuPc with positive holes of tita nia.

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2016

ABSTRACT The performance of 0.5% wt Rh/γ-AL2O3 catalyst for the dry reforming of natural gas usin... more ABSTRACT The performance of 0.5% wt Rh/γ-AL2O3 catalyst for the dry reforming of natural gas using carbon dioxide has been studied. The response surface methodology (RSM) is used to study the effect of two different operating parameters, namely the hourly space velocity at the levels 18,000, 36,000, 45,000, and 60,000 ccg−1 h−1 and the reaction temperature at the levels 600, 700, and 800°C, on the conversion of the different components comprising commercial natural gas. The RSM is used to illustrate such effect in the three dimensions and shows the location of the optimum for the conversion or production of each component.

Journal of Porous Materials, 2016

Here in, a series of titanium-modified mesoporous silica (Ti-SBA-15) was prepared by grafting tit... more Here in, a series of titanium-modified mesoporous silica (Ti-SBA-15) was prepared by grafting titanium isopropoxide. The as-synthesized Ti-SBA-15 nanocatalysts were characterized through N 2-adsorptiondesorption, XRD, TGA/DSC, TEM and EDX techniques. Sonocatalytic and sonophoto-catalytic degradation of Eriochrome Black T (EBT) dye were investigated. 88.7 % removal was achieved in 70 min by using 5 % Ti-SBA-15 through sonophotocatalytic degradation under visible light irradiation. The kinetic study revealed that photo-degradation of EBT follows pseudo-first order reaction mechanism, where the rate constant was 27.4 9 10-3 min-1 .

Journal of Water Process Engineering, 2016

Wastewater from petroleum refineries contains toxic, carcinogenic and recalcitrant chlorophenols.... more Wastewater from petroleum refineries contains toxic, carcinogenic and recalcitrant chlorophenols. This comes with the mandatory environmental aspect of the recycling of the organic wastes. This work aimed to prepare; fluorapatite (FAP) by a simple calcination process of waste animal bones (ABs), ZnO nanoparticles by a wet chemical method and ZnO/FAP binary oxide nano-bio-composite by a simple mechano-mixing technique and study their photo-catalytic degradation properties on chlorophenols. The obtained catalysts were characterized by high-resolution X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscope, Brunauer Emmett-Teller and Barret-Joyner-Halenda methods and N 2 adsorption-desorption isotherms. The three prepared catalysts showed excellent photo-catalytic degradation activity under UV-irradiation towards 3-chlorphenol and 2,3-dichlorphenol. The photo-degradation followed the Langmuir-Hinshelwood L-H kinetic model with R 2 ≥ 0.962; however, the rate constant was strongly affected by the type of the catalyst and chlorophenols. New proposed mathematical correlations were elucidated to assess the relationship between the cumulative removal of the studied chlorophenols and the production of their photocatalytic oxidation intermediates. In the view of the ubiquity, environmental compatibility, and cost-effectiveness; the prepared green FAP from ABs as a readily available, sustainable and cheap waste byproduct of food industry proved to be a favorable photo-catalyst for remediating petroleum refineries wastewater. In an attempt to enhance the photo-catalytic degradation activities of ZnO towards the chlorophenols, the mechano-mixing process suggested a new approach to produce commercial amounts of nano-biocomposites of ZnO/FAP nanostructures with high quality and suitable structural and morphological features that would revolutionize the field of biomaterials.

Chemistry and Materials Research, 2014

TiO 2 nanopowder, loaded with copper, was prepared under both impregnation and co-precipitation m... more TiO 2 nanopowder, loaded with copper, was prepared under both impregnation and co-precipitation methods. The morphology and structure of TiO 2 were studied by XRD, TEM, FTIR and BET techniques. The photocatalytic activity of samples was studied by monitoring the degradation of nitro phenol, using a UV-visible spectrophotometer. Total organic compound measurements showed that p-nitrophenol photodegradation efficiency reached 46% after 150 min over Cu-TiO 2 catalysts.

World Journal of Engineering and Technology, 2016

New J. Chem., 2016

In-situ inverse-emulsion polymerization and crosslinking of acrylamide in presence of metal oxide... more In-situ inverse-emulsion polymerization and crosslinking of acrylamide in presence of metal oxides nanoparticles producing core/shell hydrogel nanocomposites for water decolorization.

RSC Adv., 2015

Currently, 80% of global energy is supplied by carbon-based fossil fuels, which has led to concer... more Currently, 80% of global energy is supplied by carbon-based fossil fuels, which has led to concerns over the environmental impact of increasing atmospheric CO2 levels and has sparked ever-growing interest in renewable energy sources.

Journal of Nanofluids, 2015

The aim of this research is to investigate the stability of titania nanofluid by utilizing the ef... more The aim of this research is to investigate the stability of titania nanofluid by utilizing the effect of gamma irradiation on the preparation of nano titania. Nanofluids with 0.0075–0.25 wt% TiO2 loadings nanoparticles were prepared using a two-step method. Ultrasonic processing was applied to allow the homogeneity and Sodium Dodecyl Sulfate (SDS) as anionic surfactant which added to increase the stability of the prepared samples under this investigation. Several characterization techniques were adopted to visualize the stability and sedimentation rate of the prepared nanofluids viz., UV–vis spectrometry, particle size distribution, zeta potential, transmission electron microscopy (TEM) and sedimentation photo capturing. The results revealed that nanofluid prepared using TiO2 irradiated with gamma radiation during preparation are the most stable suspension within 37 days. In addition, photocatalytic activity of nanofluids was examined using Methylene Blue dye (MB) as hazardous compound. It was found that using the same amount of TiO2 sample, the TiO2 nanofluid exhibited higher catalytic efficiency for this reaction.

Reforming of natural gas with carbon dioxide to produce synthesis gas (H2 + CO) has been investig... more Reforming of natural gas with carbon dioxide to produce synthesis gas (H2 + CO) has been investigated over rhodium (0.5 wt. %) supported on γ- alumina catalyst. The detection of both major and minor components in the natural gas before and after reforming, in addition to the produced synthesis gas, requires a high sensitive gas chromatograph. This research aims to study the effect of the space velocity and temperature on the conversion of carbon dioxide and all the components of the natural gas. The space velocity 18000 mL g-1 h-1 and the temperature 800oC are the optimum operating conditions giving the highest conversion of both the natural gas and carbon dioxide, but the space velocity 36000 mL g-1 h-1 and the temperature at 700oC are the preferred conditions for production of the synthesis gas (H2 + CO).

Catalytic reforming of natural gas with carbon dioxide to produce syngas has been investigated ov... more Catalytic reforming of natural gas with carbon dioxide to produce syngas has been investigated over ruthenium (0.5 wt %) supported on γ-alumina. Capillary gas chromatography was used to detect and evaluate the hydrocarbons and non-hydrocarbons in the natural gas before and after reaction. This research aims to study the effect of the space velocity and temperature on the conversion of carbon dioxide and all the components of the natural gas. The space velocity 36000 ml g-1h-1 and the temperature 800oC are the optimum operating conditions giving the highest conversion of both the methane and carbon dioxide, but the space velocity 18000 ml g-1 h-1 and the temperature at 800oC are the preferred conditions for production of the hydrogen and carbon monoxide (synthesis gas).

The activities of Cu/TiO 2 prepared by a gamma-ray irradiation and Cu-doped TiO 2 sample prepared... more The activities of Cu/TiO 2 prepared by a gamma-ray irradiation and Cu-doped TiO 2 sample prepared by a sol-gel method in photodegradation of methyl orange dye were examined. Structural and properties of the solids investigated have been studied using XRD, EDX, TEM, FTIR and BET techniques. The particles of the prepared TiO 2 have high surface area and an anatase phase structure. The remaining concentrations of 10 ppm MO at PH 1 reaches 0.13 and 2.25 ppm after 120 min under UV irradiation using 0.15g/L of Cu/TiO 2 and Cu-TiO 2 catalysts respectively.

Journal of Water Process Engineering, 2015

Factorial experiments with five factors; stirring rate, process time and temperature, initial dye... more Factorial experiments with five factors; stirring rate, process time and temperature, initial dye concentration and biosorbent dosage at three levels were conducted based on central composite design of experiments to investigate their effect on Basic Blue 41 dye biosorption onto bioethanol fermentation spent waste biomass of Saccharomyces cerevisiae. A highly statistically significant quadratic model at 95% confidence level (p < 0.0001,R 2 0.9612andR 2 adj 0.9386) was developed to charcterize the influence of these variables on biosorption effeciency. Response surface methodology was employed to optimize the process, recording maximum biosorption % of ≈94% (23.5 mg/g) under static condition, within 14 h at 20 • C using 0.6% biosorbent in an initial dye solution of 150 mg/L. Approximately 92% of adsorbed dye was desorbed by elution with self-clean acid TiO 2 hydrosol (pH 2) and the regenerated biosorbent was employed for four successive cycles. The photo-catalytic degradation of the desorbed dye under ultraviolet illumination (8 W) followed the pseudo first order kinetic model (R 2 0.9687) with apparent rate constant K app of ≈0.0043 min −1. The proposed integrating biosorption with self-clean desorption and photo-catalytic degradation process, resulted in no secondary pollution in the form of any concentrated wastes, thus has important environmental and economic aspects.

Egyptian Journal of Petroleum, 2014

Two nano-titania catalysts were prepared using two economically varying titanium precursors: tita... more Two nano-titania catalysts were prepared using two economically varying titanium precursors: titanium tetrachloride (A) and titanium isopropoxide (B). The catalysts were calcined at temperatures of 500°C, 600°C and 700°C and characterized using X-ray diffraction (XRD), electron diffraction (ED), BET surface properties and high resolution transmission microscopy (HRTEM). The calcined catalysts were found to differ markedly in their physical characters and TiO 2 phases produced as well as their photocatalytic activities. The anatase titania phase diminished from 100% to 83% in TiO 2 A but from 64% to zero in TiO 2 B via temperature increase from 500°C to 700°C, due to transforming anatase to rutile. The brookite TiO 2 phase only appeared (17%) in catalyst B500. In general, the catalyst of choice is A600 by virtue of many compositional, economical and catalytic advantages.

Materials for Renewable and Sustainable Energy, 2014

In this work, the influence of metal type (Ni and Co) and preparation method (co-precipitation an... more In this work, the influence of metal type (Ni and Co) and preparation method (co-precipitation and impregnation) on catalytic gasoline steam reforming (CGSR) using nano-Al 2 O 3 support were studied at different reaction temperature (500-800°C). The structure and surface properties of fresh and spent catalysts were tested by different characterization tools such as TGA, TPR, XRD, HRTEM, BET surface areas and Raman spectroscopy. Results show that product distribution is dependent on both preparation method and metal type. Co/Al 2 O 3 is the most selective catalyst for hydrogen production from GSR reaction; H 2 selectivity reached 70 % over this catalyst at 800°C. While, when considering hydrogen production and carbon deposition in the meantime, Ni/Al 2 O 3 is the best one because of the generation of non-deactivating carbon on its surface. CO conversion represented as CO 2 /(CO ? CO 2) is an indication of the WGS reaction, over all of the prepared catalysts, WGS reaction was preferred at low temperature. On the other hand, we can show that Ni catalysts favor WGS reaction more than that of co catalyst. Moreover, a higher thermal stability and graphitization degree of deposit carbon were obtained on Ni-Al 2 O 3 and Co/Al 2 O 3. Keywords Gasoline reforming Á Carbon deposition Á Hydrogen production Á Nano-Al 2 O 3 catalysts

Arabian Journal of Chemistry, 2017

Ru doped titania was prepared by the impregnation method and examined for the photocatalytic degr... more Ru doped titania was prepared by the impregnation method and examined for the photocatalytic degradation of 2-chlorophenol at ambient conditions. Ru/TiO 2 photocatalysts with metal loadings of 0.2, 0.4, 0.6 and 0.8 wt% were prepared and characterized using TEM, XRD, FTIR, S BET and EDX analyses. The degradation of 2-chlorophenol (2-CP) in the aqueous phase was investigated under irradiation at 254 nm, employing either photodegradation in the presence of titania, Ru doped titania or photolysis, to compare the efficiency of these photoinduced advanced oxidation techniques. Photocatalysis under visible irradiation was also investigated. The removal efficiency arrived at 50% using 0.2% Ru/TiO 2 catalyst.

RSC Adv., 2015

The catalytic activity of a metal free nano-particle, whose size ranged from 1–10 nm, was studied... more The catalytic activity of a metal free nano-particle, whose size ranged from 1–10 nm, was studied in ethanol steam reforming reaction for hydrogen production.

Journal of Environmental Chemical Engineering, 2021

Abstract This work was undertaken to provide a new potent route for wastewater treatment by devel... more Abstract This work was undertaken to provide a new potent route for wastewater treatment by developing a hybrid photocatalyst from waste rice straw. On this basis, rice straw-based SiO2 was utilized as a platform to synthesize a ternary β-Ga2O3-TiO2-SiO2 nanocomposite with type-I heterojunction band alignment using the mechanochemical method. The categorical factorial design was employed to optimize the synergistic effect between adsorption and photocatalytic performance of the nanocomposite towards removing p-nitrophenol (PNP) from wastewater under various experimental conditions. The optimization results indicated the negligible impact of catalyst dose ( X c ) and total dissolved solids ( X T D S ) on the photocatalysis with the increase of pre-adsorption time (Xads) from 60 to 180 min. In contrast, the adsorption/photocatalytic performance of ꞵ-Ga2O3-TiO2-SiO2 was found to be dependent on the solution pH ( X p H , with a percentage contribution (PC) of 26.1 %) due to its effect on the photocatalyst surface charge and the dissociation process of PNP molecules. At optimum conditions ( X c = 4.0 g/L, X p H = 6.0, X T D S = 1000 mg/L, and Xads = 180 min), the β-Ga2O3-TiO2-SiO2 exhibited high efficiency to degrade 92.4 ± 3.8 % and 68.65 ± 4.3 % of PNP (25 mg/L) after 120 min UV and visible irradiation, with kinetic rates (k) of 0.62 and 0.53 mg/(g.min), respectively. This improved performance was due to the synergism between (i) the high adsorption of PNP (k = 0.017 mg/(g.min)) on SiO2 and (ii) the effective separation of photogenerated charges between ꞵ-Ga2O3 and TiO2. The high-performance stability (up to 3 cycles) of β-Ga2O3-TiO2-SiO2 was also demonstrated towards UV/visible-induced photodegradation of organic contaminants in real petrochemical wastewater.

Journal of Water Process Engineering, 2017

A photo-catalyst of mesoporous silicate SBA-15 doped with 15%MoO 3 was synthesized by modified so... more A photo-catalyst of mesoporous silicate SBA-15 doped with 15%MoO 3 was synthesized by modified sol-gel process and then characterized by SBET, XRD, HRTEM/EDX, TGA and optical techniques. The photo-catalytic performances of 15%Mo/SBA-15 were tested in the photo-remediation of wastewater composed of multi-organic pollutants (i.e., aromatics, phenols, and dyes) at different light sources of visible (400 nm), UVB (316 nm)and UVC (254 nm) irradiation. The photo-catalytic activities of the 15%Mo/SBA-15 were considerably greater under UVC irradiation, which is coincident with 15%Mo/SBA-15 calculated band gap of 3.5 eV. Further, wastewater treatment rate was ranked in the order of aromatic > phenolic > dyes with the rate of 95%, 69%, and 14%, respectively after 120 min UVC irradiation time. A statistical analysis, using both parametric (one way ANOVA) and nonparametric (Kruskal-Wallis) methodologies, were developed to validate the experimental comparison between neat SBA-15 and 15%Mo/SBA-15 based on structural properties, light intensity and the type of organic contaminants are the key factors influencing the photo-catalytic degradation rate. The kinetic rate of the wastewater photo-catalytic remediation was found to be ranked in the order of benzene > anthracene > pyrene > naphthalene within aromatic contaminants, hydroxyphenyl ≈ chlorophenols > phenol within the phenolic group, and no significant difference between methyl orange and methyl red within dyes contaminants over 15%Mo/SBA-15. Results suggested that the developed 15%Mo/SBA-15 could be used as efficient photocatalysts for the treatment of petroleum and petrochemical wastewater with aromatic and phenolic hazardous, but not efficient for the treatment of textile wastewater pollutants.

Journal of Sol-Gel Science and Technology, 2017

A series of zinc-doped titania–silica tricomposites (Zn/xTi–SiO2) with different Ti-molar ratios ... more A series of zinc-doped titania–silica tricomposites (Zn/xTi–SiO2) with different Ti-molar ratios were prepared by sol–gel method. Zn+2 ions of 25 wt% were doped on the photo-catalysts using wet impregnation method. The as-synthesized Zn/xTi–SiO2 nano-catalysts were characterized through N2-adsorption–desorption, X-ray diffraction, transmission electron microscope, fourier transform infrared, dynamic light scatterings, photoluminescence, and diffuse reflectance techniques. Photo-catalytic degradation of phenol (PhOH) under 8-W ultraviolet C irradiation was examined. 96% removal was achieved in 150 min by using Zn/20Ti–SiO2. The kinetic study revealed that photo-degradation of PhOH follows pseudo-first order reaction mechanism, where the rate constant was 77.4 × 10−3 min−1. One-way analysis of variance, as well as Student’t-test at α = 0.05 level (95% confidence interval) was performed to comparing the means of the results obtained.Graphical Abstract

Canadian Chemical Transactions, 2014

Rice straw ash (RSA)-based composites, containing titania (TiO 2 , 50%) or copper phthalocyanine ... more Rice straw ash (RSA)-based composites, containing titania (TiO 2 , 50%) or copper phthalocyanine complex (CuPc, 1.0%) or TiO 2-CuPc combination, were prepared in disc-shaped forms. Mechano-mixing of TiO 2 could develop the mesoporous nature of the composites. TiO 2 existed as nanoparticles of average sizes in the range, 16-20 nm, homogeneously dispersed on the surface of the ash matrix. Compression of the solids using polymer binder led to only a small decrease in surface parameters, pore dimensions and average size of contained silica nanocrystallites. The composites discs were applied in the adsorption and photo-catalytic degradation (using visible light) of methylene blue (MB) dye, at ambient temperature and neutral pH. The rate of adsorption of MB on the studied composites deceased, according to the second order kinetic model, in the order: RSA-TiO 2-CuPc > RSA-TiO 2 > RSA > RSA-CuPc. TiO 2 or TiO 2-CuPc combination enhanced the rate of MB adsorption due to development of the composite surface characteristics. The rate of visible-photodegradation of MB, in terms of the first order kinetic model, deceased in the order: RSA ≈ RSA-TiO 2 > RSA-CuPc > RSA-TiO 2-CuPc. TiO 2 , by generated hydroxyl radicals (. OH) and superoxide radicals (. O 2-) and CuPc complex, by generated singlet oxygen (1 O 2) through photosensitization role, could activate the rice straw ash toward the MB photo-degradation in aqueous solutions. Some retardation in photocatalytic degradation rate observed in presence of hybrids derived from CuPc and TiO 2 was attributed to probable recombination of most of electrons donated by the bound CuPc with positive holes of tita nia.

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2016

ABSTRACT The performance of 0.5% wt Rh/γ-AL2O3 catalyst for the dry reforming of natural gas usin... more ABSTRACT The performance of 0.5% wt Rh/γ-AL2O3 catalyst for the dry reforming of natural gas using carbon dioxide has been studied. The response surface methodology (RSM) is used to study the effect of two different operating parameters, namely the hourly space velocity at the levels 18,000, 36,000, 45,000, and 60,000 ccg−1 h−1 and the reaction temperature at the levels 600, 700, and 800°C, on the conversion of the different components comprising commercial natural gas. The RSM is used to illustrate such effect in the three dimensions and shows the location of the optimum for the conversion or production of each component.

Journal of Porous Materials, 2016

Here in, a series of titanium-modified mesoporous silica (Ti-SBA-15) was prepared by grafting tit... more Here in, a series of titanium-modified mesoporous silica (Ti-SBA-15) was prepared by grafting titanium isopropoxide. The as-synthesized Ti-SBA-15 nanocatalysts were characterized through N 2-adsorptiondesorption, XRD, TGA/DSC, TEM and EDX techniques. Sonocatalytic and sonophoto-catalytic degradation of Eriochrome Black T (EBT) dye were investigated. 88.7 % removal was achieved in 70 min by using 5 % Ti-SBA-15 through sonophotocatalytic degradation under visible light irradiation. The kinetic study revealed that photo-degradation of EBT follows pseudo-first order reaction mechanism, where the rate constant was 27.4 9 10-3 min-1 .

Journal of Water Process Engineering, 2016

Wastewater from petroleum refineries contains toxic, carcinogenic and recalcitrant chlorophenols.... more Wastewater from petroleum refineries contains toxic, carcinogenic and recalcitrant chlorophenols. This comes with the mandatory environmental aspect of the recycling of the organic wastes. This work aimed to prepare; fluorapatite (FAP) by a simple calcination process of waste animal bones (ABs), ZnO nanoparticles by a wet chemical method and ZnO/FAP binary oxide nano-bio-composite by a simple mechano-mixing technique and study their photo-catalytic degradation properties on chlorophenols. The obtained catalysts were characterized by high-resolution X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscope, Brunauer Emmett-Teller and Barret-Joyner-Halenda methods and N 2 adsorption-desorption isotherms. The three prepared catalysts showed excellent photo-catalytic degradation activity under UV-irradiation towards 3-chlorphenol and 2,3-dichlorphenol. The photo-degradation followed the Langmuir-Hinshelwood L-H kinetic model with R 2 ≥ 0.962; however, the rate constant was strongly affected by the type of the catalyst and chlorophenols. New proposed mathematical correlations were elucidated to assess the relationship between the cumulative removal of the studied chlorophenols and the production of their photocatalytic oxidation intermediates. In the view of the ubiquity, environmental compatibility, and cost-effectiveness; the prepared green FAP from ABs as a readily available, sustainable and cheap waste byproduct of food industry proved to be a favorable photo-catalyst for remediating petroleum refineries wastewater. In an attempt to enhance the photo-catalytic degradation activities of ZnO towards the chlorophenols, the mechano-mixing process suggested a new approach to produce commercial amounts of nano-biocomposites of ZnO/FAP nanostructures with high quality and suitable structural and morphological features that would revolutionize the field of biomaterials.

Chemistry and Materials Research, 2014

TiO 2 nanopowder, loaded with copper, was prepared under both impregnation and co-precipitation m... more TiO 2 nanopowder, loaded with copper, was prepared under both impregnation and co-precipitation methods. The morphology and structure of TiO 2 were studied by XRD, TEM, FTIR and BET techniques. The photocatalytic activity of samples was studied by monitoring the degradation of nitro phenol, using a UV-visible spectrophotometer. Total organic compound measurements showed that p-nitrophenol photodegradation efficiency reached 46% after 150 min over Cu-TiO 2 catalysts.

World Journal of Engineering and Technology, 2016

New J. Chem., 2016

In-situ inverse-emulsion polymerization and crosslinking of acrylamide in presence of metal oxide... more In-situ inverse-emulsion polymerization and crosslinking of acrylamide in presence of metal oxides nanoparticles producing core/shell hydrogel nanocomposites for water decolorization.

RSC Adv., 2015

Currently, 80% of global energy is supplied by carbon-based fossil fuels, which has led to concer... more Currently, 80% of global energy is supplied by carbon-based fossil fuels, which has led to concerns over the environmental impact of increasing atmospheric CO2 levels and has sparked ever-growing interest in renewable energy sources.

Journal of Nanofluids, 2015

The aim of this research is to investigate the stability of titania nanofluid by utilizing the ef... more The aim of this research is to investigate the stability of titania nanofluid by utilizing the effect of gamma irradiation on the preparation of nano titania. Nanofluids with 0.0075–0.25 wt% TiO2 loadings nanoparticles were prepared using a two-step method. Ultrasonic processing was applied to allow the homogeneity and Sodium Dodecyl Sulfate (SDS) as anionic surfactant which added to increase the stability of the prepared samples under this investigation. Several characterization techniques were adopted to visualize the stability and sedimentation rate of the prepared nanofluids viz., UV–vis spectrometry, particle size distribution, zeta potential, transmission electron microscopy (TEM) and sedimentation photo capturing. The results revealed that nanofluid prepared using TiO2 irradiated with gamma radiation during preparation are the most stable suspension within 37 days. In addition, photocatalytic activity of nanofluids was examined using Methylene Blue dye (MB) as hazardous compound. It was found that using the same amount of TiO2 sample, the TiO2 nanofluid exhibited higher catalytic efficiency for this reaction.

Reforming of natural gas with carbon dioxide to produce synthesis gas (H2 + CO) has been investig... more Reforming of natural gas with carbon dioxide to produce synthesis gas (H2 + CO) has been investigated over rhodium (0.5 wt. %) supported on γ- alumina catalyst. The detection of both major and minor components in the natural gas before and after reforming, in addition to the produced synthesis gas, requires a high sensitive gas chromatograph. This research aims to study the effect of the space velocity and temperature on the conversion of carbon dioxide and all the components of the natural gas. The space velocity 18000 mL g-1 h-1 and the temperature 800oC are the optimum operating conditions giving the highest conversion of both the natural gas and carbon dioxide, but the space velocity 36000 mL g-1 h-1 and the temperature at 700oC are the preferred conditions for production of the synthesis gas (H2 + CO).

Catalytic reforming of natural gas with carbon dioxide to produce syngas has been investigated ov... more Catalytic reforming of natural gas with carbon dioxide to produce syngas has been investigated over ruthenium (0.5 wt %) supported on γ-alumina. Capillary gas chromatography was used to detect and evaluate the hydrocarbons and non-hydrocarbons in the natural gas before and after reaction. This research aims to study the effect of the space velocity and temperature on the conversion of carbon dioxide and all the components of the natural gas. The space velocity 36000 ml g-1h-1 and the temperature 800oC are the optimum operating conditions giving the highest conversion of both the methane and carbon dioxide, but the space velocity 18000 ml g-1 h-1 and the temperature at 800oC are the preferred conditions for production of the hydrogen and carbon monoxide (synthesis gas).

The activities of Cu/TiO 2 prepared by a gamma-ray irradiation and Cu-doped TiO 2 sample prepared... more The activities of Cu/TiO 2 prepared by a gamma-ray irradiation and Cu-doped TiO 2 sample prepared by a sol-gel method in photodegradation of methyl orange dye were examined. Structural and properties of the solids investigated have been studied using XRD, EDX, TEM, FTIR and BET techniques. The particles of the prepared TiO 2 have high surface area and an anatase phase structure. The remaining concentrations of 10 ppm MO at PH 1 reaches 0.13 and 2.25 ppm after 120 min under UV irradiation using 0.15g/L of Cu/TiO 2 and Cu-TiO 2 catalysts respectively.

Journal of Water Process Engineering, 2015

Factorial experiments with five factors; stirring rate, process time and temperature, initial dye... more Factorial experiments with five factors; stirring rate, process time and temperature, initial dye concentration and biosorbent dosage at three levels were conducted based on central composite design of experiments to investigate their effect on Basic Blue 41 dye biosorption onto bioethanol fermentation spent waste biomass of Saccharomyces cerevisiae. A highly statistically significant quadratic model at 95% confidence level (p < 0.0001,R 2 0.9612andR 2 adj 0.9386) was developed to charcterize the influence of these variables on biosorption effeciency. Response surface methodology was employed to optimize the process, recording maximum biosorption % of ≈94% (23.5 mg/g) under static condition, within 14 h at 20 • C using 0.6% biosorbent in an initial dye solution of 150 mg/L. Approximately 92% of adsorbed dye was desorbed by elution with self-clean acid TiO 2 hydrosol (pH 2) and the regenerated biosorbent was employed for four successive cycles. The photo-catalytic degradation of the desorbed dye under ultraviolet illumination (8 W) followed the pseudo first order kinetic model (R 2 0.9687) with apparent rate constant K app of ≈0.0043 min −1. The proposed integrating biosorption with self-clean desorption and photo-catalytic degradation process, resulted in no secondary pollution in the form of any concentrated wastes, thus has important environmental and economic aspects.

Egyptian Journal of Petroleum, 2014

Two nano-titania catalysts were prepared using two economically varying titanium precursors: tita... more Two nano-titania catalysts were prepared using two economically varying titanium precursors: titanium tetrachloride (A) and titanium isopropoxide (B). The catalysts were calcined at temperatures of 500°C, 600°C and 700°C and characterized using X-ray diffraction (XRD), electron diffraction (ED), BET surface properties and high resolution transmission microscopy (HRTEM). The calcined catalysts were found to differ markedly in their physical characters and TiO 2 phases produced as well as their photocatalytic activities. The anatase titania phase diminished from 100% to 83% in TiO 2 A but from 64% to zero in TiO 2 B via temperature increase from 500°C to 700°C, due to transforming anatase to rutile. The brookite TiO 2 phase only appeared (17%) in catalyst B500. In general, the catalyst of choice is A600 by virtue of many compositional, economical and catalytic advantages.

Materials for Renewable and Sustainable Energy, 2014

In this work, the influence of metal type (Ni and Co) and preparation method (co-precipitation an... more In this work, the influence of metal type (Ni and Co) and preparation method (co-precipitation and impregnation) on catalytic gasoline steam reforming (CGSR) using nano-Al 2 O 3 support were studied at different reaction temperature (500-800°C). The structure and surface properties of fresh and spent catalysts were tested by different characterization tools such as TGA, TPR, XRD, HRTEM, BET surface areas and Raman spectroscopy. Results show that product distribution is dependent on both preparation method and metal type. Co/Al 2 O 3 is the most selective catalyst for hydrogen production from GSR reaction; H 2 selectivity reached 70 % over this catalyst at 800°C. While, when considering hydrogen production and carbon deposition in the meantime, Ni/Al 2 O 3 is the best one because of the generation of non-deactivating carbon on its surface. CO conversion represented as CO 2 /(CO ? CO 2) is an indication of the WGS reaction, over all of the prepared catalysts, WGS reaction was preferred at low temperature. On the other hand, we can show that Ni catalysts favor WGS reaction more than that of co catalyst. Moreover, a higher thermal stability and graphitization degree of deposit carbon were obtained on Ni-Al 2 O 3 and Co/Al 2 O 3. Keywords Gasoline reforming Á Carbon deposition Á Hydrogen production Á Nano-Al 2 O 3 catalysts

Arabian Journal of Chemistry, 2017

Ru doped titania was prepared by the impregnation method and examined for the photocatalytic degr... more Ru doped titania was prepared by the impregnation method and examined for the photocatalytic degradation of 2-chlorophenol at ambient conditions. Ru/TiO 2 photocatalysts with metal loadings of 0.2, 0.4, 0.6 and 0.8 wt% were prepared and characterized using TEM, XRD, FTIR, S BET and EDX analyses. The degradation of 2-chlorophenol (2-CP) in the aqueous phase was investigated under irradiation at 254 nm, employing either photodegradation in the presence of titania, Ru doped titania or photolysis, to compare the efficiency of these photoinduced advanced oxidation techniques. Photocatalysis under visible irradiation was also investigated. The removal efficiency arrived at 50% using 0.2% Ru/TiO 2 catalyst.

RSC Adv., 2015

The catalytic activity of a metal free nano-particle, whose size ranged from 1–10 nm, was studied... more The catalytic activity of a metal free nano-particle, whose size ranged from 1–10 nm, was studied in ethanol steam reforming reaction for hydrogen production.