mohamed G shahien | Beni-Suef University (original) (raw)

Papers by mohamed G shahien

*Corresponding Author: Moaaz K. Seliem, Lecturer, Beni-Suef University, Faculty of Science, Geolo... more *Corresponding Author: Moaaz K. Seliem, Lecturer, Beni-Suef University, Faculty of Science, Geology Department, Egypt. 4423 SYNTHESIS OF NA-A ZEOLITES FROM NATURAL AND THERMALLY ACTIVATED EGYPTIAN KAOLINITE: CHARACTERIZATION AND COMPETITIVE ADSORPTION OF COPPER IONS FROM AQUEOUS SOLUTIONS Moaaz K. Seliem*, E.A. Mohamed, A.Q. Selim, M. G. Shahien and Mostafa R. Abukhadra Beni-Suef University, Faculty of Science, Geology Department, Egypt.

Applied Clay Science, 2011

This study investigated the adsorption of toluene as a non-ionic organic contaminant by organosil... more This study investigated the adsorption of toluene as a non-ionic organic contaminant by organosilicas and organo-clay minerals. Different organic surfactants were used to prepare a variety of MCM-41 molecular sieves at room temperature while cetyltrimethylammonium (CTMA) bromide was used to synthesize MCM-48 mesoporous material under hydrothermal conditions. Organo-clay minerals were synthesized under hydrothermal conditions using synthetic low-charge Na-fluorophlogopite micas with CTMA bromide as organic surfactant. All synthetic organosilicas and organo-clay minerals, the latter including those procured from two commercial sources were characterized by powder X-ray diffraction (XRD) and their toluene sorption properties were investigated. Among organosilicas, MCM-48 exhibited the highest distribution coefficient (Kd) value of toluene (95 ± 9 L/kg). An organo-clay mineral, Nanomer® PGW montmorillonite modified with CTMA bromide (Nanomer® 1.28E) showed the maximum Kd value (345 ± 22...

Construction and Building Materials

This work is the first attempt to study the possibility of incorporating three different types of... more This work is the first attempt to study the possibility of incorporating three different types of Egyptian serpentine aggregates (antigorite, lizardite and chrysotile) with different serpentinization grades as fine and coarse aggregates for normal concrete production. The results of physical and mechanical tests for each type of aggregate were compared to the others. In addition, the effect of serpentinization grade on their mineralogical composition, physico-mechanical and morphological properties of was evaluated and compared. The results were analyzed by using sophisticated tools such as X-ray diffraction, thermogravimetry/ differential thermogravimetry and scanning electron microscopy. The results revealed that the physical, mechanical and microstructural properties of serpentine-based concretes were negatively influenced by the progress of serpentinization and deformation processes. The antigorite aggregate showed the lowest serpentinization grade compared to the others (i.e. l...

Separation and Purification Technology

ABSTRACT

Applied Clay Science, 2010

Mn-kaolinite containing both Mn and Al in the octahedral sheet was prepared under hydrothermal co... more Mn-kaolinite containing both Mn and Al in the octahedral sheet was prepared under hydrothermal conditions of 100–200°C for 6–96h by using Al-nitrate, Mn-carbonate, silicic acid and aqueous solutions of NaOH or KOH. The synthetic phases were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and X-ray Absorption Near Edge Structure (XANES) spectroscopy. The results showed

Materials Research Innovations, 2010

ABSTRACT Mesoporous MCM-41 silica and rice husk composites were synthesised under hydrothermal co... more ABSTRACT Mesoporous MCM-41 silica and rice husk composites were synthesised under hydrothermal conditions using cetyltrimethylammonium bromide (CTAB) as an organic template, aqueous ammonia solution (NH4OH) and rice husk, the latter as a silica source and substrate for the deposition of MCM-41. Both untreated and carbonised rice husks were used for preparing composites at a temperature of 100–120°C for 24–48 h. The as synthesised composites or hybrid materials were characterised by using XRD and SEM and they were found to be useful for the uptake of perchlorate. These composites could be used to separate perchlorate from solutions in column operation without the necessity for their pelletisation because the rice husk substrates are several millimetres in size.

Applied Clay Science, 2013

ABSTRACT

Developments in Precambrian …, 2004

Ophiolites of mid-Neoproterozoic age are abundant in the Arabian-Nubian Shield (ANS) of NE Africa... more Ophiolites of mid-Neoproterozoic age are abundant in the Arabian-Nubian Shield (ANS) of NE Africa and Arabia. ANS ophiolites range in age from 690 to 890 Ma and litter a region that is 3000 km N-S and > 1000 km E-W. In the northern ANS, ophiolites occur as nappe complexes marking suture zones between terranes. Although dismembered and altered, all of the diagnostic components of ophiolites can be found: harzburgite, cumulate ultramafics, layered as well as higher level gabbro and plagiogranite, sheeted dikes, and pillowed basalt. Allochthonous mafic-ultramafic complexes in the southern ANS, in Ethiopia and Eritrea, are interpreted as ophiolites, but are more deformed and metamorphosed than those in the north. Reconstructed ophiolitic successions have crustal thicknesses of 2.5 to 5 km. The ANS ophiolitic mantle was mostly harzburgitic, containing magnesian olivines and spinels that have compositions consistent with extensive melting. Cr# for spinels in ANS harzburgites are mostly > 60, comparable to spinels from modern forearcs and distinctly higher than spinels from mid-ocean ridges and backarc basin peridotites. ANS ophiolites are often associated with a thick (1-3 km) sequence of cumulate ultramafic rocks, which define a transition zone between seismic and petrologic Mohos. These cumulates are dominated by dunite, with subordinate pyroxene-rich lithologies. Cumulate ultramafics transition upwards into layered gabbro. Several crystallization sequences are inferred from ANS transition zones and cumulate gabbro sections. In all samples studied, olivine and spinel crystallized first, followed (in order of decreasing abundance) by cpx-plag, cpxopx-plag, and opx-cpx-plag. ANS ophiolitic lavas mostly define a subalkaline suite characterized by low K and moderate Ti contents, that has both tholeiitic and calc-alkaline affinities and includes a significant, although subordinate, amount of boninites. The lavas are fractionated (mean Mg# = 55) but have higher abundances of Cr (mean = 380 ppm) and Ni (mean = 135 ppm) than would be expected for such a low Mg#. The ANS ophiolitic lavas include both LREE-depleted and LREE-enriched varieties, but as a group are slightly

Raw kaolinite was used as a precursor for several types of modified kaolinite. The modification p... more Raw kaolinite was used as a precursor for several types of modified kaolinite. The modification processes included modification by sodium hydroxide, sodium phosphate, sodium sulfate, CTAB, and sodium acetate. The structural, morphological, and chemical properties of raw kaolinite and the modified products were evaluated using XRD, SEM, TEM, and FT-IR analyses. The modified products were used as adsorbent materials for acidic Congo red dye from aqueous solutions. The adsorption processes were evaluated as a function of reaction time, initial dye concentration, and adsorbent masses. Phosphate-modified kaolinite achieved the best removal results followed by sulfate-modified kaolinite and kaolinite sample modified by CTAB. Kinetic studies indicated that the adsorption equilibrium was obtained after 360 min for the samples, which were modified by NaOH and CTAB, whereas the modified samples that were treated by phosphate, sulfate and, acetate achieve the equilibrium after 240 min. The adsorption by all the products is of chemical nature occurs through energetically heterogeneous surfaces and fitted well with pseudo-second order kinetic model. The equilibrium studies revealed that the adsorption using kaolinite modified by sodium hydroxide, sodium phosphate, and sodium sulfate occurs in monolayer form and represented well by Langmuir model. The estimated q max values are 136.98, 149.25, and 135.13 mg/g for the three products in order. The uptake using modified kaolinite by CTAB and sodium acetate shows more fitting with Tamkin and Freundlich isotherm models rather than with Langmuir model. Graphical Abstract Kaolinite sample was modified by organic and inorganic salts to enhance its adsorption properties. Modified kaolinite samples exhibit changes in the structural and morphological features. The modified samples showed high adsorption capacity than raw kaolinite. Highlights ● Kaolinite was modified by several inorganic and organic salts. ● Effect of modification and the structural and morphological features was investigated. ● The adsorption behavior of the modified products for Congo red dye was addressed. ● The change in the adsorption behavior was studied through kinetic and isotherm studies.

This paper aims to evaluate and upgrade the quality of quartz mining by-products through acid lea... more This paper aims to evaluate and upgrade the quality of quartz mining by-products through acid leaching process. The quartz samples were collected as gold mine by-products from El Sid-Fawakhir gold mine, Qift-Quseir, Eastern Desert, Egypt and characterized using XRF and polarized transmitted optical microscope. The present magnetic mineral impurities were detected using Frantz Isodynamic Tester. Suitability of acid leaching utilizing oxalic acid as an efficient technique for considerable reduction of the associated impurities was evaluated based on Response Surface methodology and face centered central composite design (CCD). The quartz sample was classified as low-quality quartz with low silica content (99.3%) which can't match the requirements of wide range of applications. The main detected impurities are muscovite, biotite, sericite, pyrite and iron oxide. The present magnetic impurities represent about 2.72% of the total sample. The leaching process at the optimum conditions of temperature, time and oxalic acid concentration removes ∼ 36% of the iron. This associated with a clear reduction of other magnetic impurities and noticeable enhancing in the silica content to about 99.56%. Magnetic purification followed by oxalic acid leaching for the quartz samples give better results as the iron content was reduced to about 0.001% and the silica content increased to about 99.9% which match the specifications of most of the typical high technical applications.

From the second order polynomial model, the predicted optimum conditions for maximum removal of s... more From the second order polynomial model, the predicted optimum conditions for maximum removal of safranin (100%) are 365 min contact time, 0.3 g dose, 5 g/l NaCl and pH 6 at initial concentration 127 mg/l.

Refined natural Fe-chromite was characterized by XRD, FT-IR, reflected polarized microscope, XRF ... more Refined natural Fe-chromite was characterized by XRD, FT-IR, reflected polarized microscope, XRF and UV spectrophotometer. Photocatalytic degradation and photo-Fenton oxidation of Congo red dye by Fe-chromite was investigated using 1 mL H 2 O 2. The degradation of dye was studied as a function of illumination time, chromite mass, initial dye concentration, and pH. Fe-chromite acts as binary oxide system from chromium oxide and ferrous oxide. Thus, it exhibits photocatalytic properties under UV illumination and photo-Fenton oxidation after addition of H 2 O 2. The degradation in the presence of H 2 O 2 reached the equilibrium stage after 8 h (59.4%) but in the absence of H 2 O 2 continued to 12 h (54.6%). Photocatalytic degradation results fitted well with zero, first order and second order kinetic model but it represented by second order rather than by the other models. While the photo-Fenton oxidation show medium fitting with the second order kinetic model only. The values of kinetic rate constants for the photo-Fenton oxidation were greater than those for the photocatalytic degradation. Thus, degradation of Congo red dye using chromite as catalyst is more efficient by photo-Fenton oxidation. Based on the response surface analysis, the predicted optimal conditions for maximum removal of Congo red dye by photocatalytic degradation (100%) were 12 mg/l, 0.14 g, 3, and 11 h for dye concentration , chromite mass, pH, and illumination time, respectively. Moreover, the optimum condition for photo-Fenton oxidation of dye (100%) is 13.5 mg/l, 0.10 g, 4, and 10 h, respectively.

Natural bituminous coal was used as a precursor in the synthesis of different modified products. ... more Natural bituminous coal was used as a precursor in the synthesis of different modified products. The modification of coal was performed by treating it with nitric acid (N-coal), coating its surface by zinc oxide nanoparticles (Z-coal), and converting it into porous graphite (PG). The effect of modification processes on the structures, morphologies, and optical properties was followed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR), and UV/VIS spectrophotometer analysis. The surface of N-coal grains becomes smoother than the surface of raw coal grains due to the removal of the associated impurities and the formation of nitrogen function groups. For Z-coal, the whole surface of coal grains appears to be completely covered by agglomerated ZnO nanoparticles of massive density and irregular shapes. The average crystallite size of the formed ZnO is ~22.2 nm and density of dislocations is 2.029 × 10 −3 dislocation/nm 2. Also, the removal of safranin-T dye by natural bituminous coal and its modified forms was investigated as a function of contact time, adsorbent mass, initial dye concentration , and pH value. At pH 8, the PG showed higher efficiency (96%) than Z-coal (93.5%), N-coal (74.5%), and natural coal (62%) after 2 h for 0.1 g on 100 mg/L dye. The obtained results are well fitted by pseudo-second-order kinetic than by intraparticle diffusion and Elovich kinetic models for the adsorption by N-coal, Z-coal, and PG, whereas the adsorp-tion by raw coal is well fitted with both pseudo-second-order and Elovich kinetic models. The Langmuir isotherm model fits well the equilibrium adsorption isotherm of safranin by raw coal and its modified forms. The values of maximum adsorption capacity were calculated for raw coal, N-coal, Z-coal, and PG to be 21.3, 27.4, 32.46, and 33.67 mg/g, respectively. A monolayer model with one energy and a monolayer model with two energies as advanced equilibrium models were investigated for more physical interpretation of the ad-sorption process. The calculated parameters (number of adsorbed molecules per site and number of receptor sites per unit mass) reflected the role of modification processes in the adsorption behavior of safranin.

Synthetic dyes are common water contaminants that impair water quality and cause diseases such as... more Synthetic dyes are common water contaminants that impair water quality and cause diseases such as der-matitis, cancer and dysfunction of kidneys. There is therefore a need for adsorbent materials to remove dyes from water. Here a bentonite/zeolite-NaP composite was synthesized by alkaline treatment of bentonite at 150 °C for 4 h. The composite exhibits nearly cubic zeolite-NaP crystals dispersed throughout bentonite aggregates. This composite has 512 m 2 /g surface area, 387 meq/100 g cation exchange capacity and 5.4 nm average pore diameter. The composite shows high removal efficiency for methylene blue, of 94%, and Congo red, of 93%, after 720 min at an initial concentration of 5 mg/l.

Synthetic dyes are common water contaminants that impair water quality and cause diseases such as... more Synthetic dyes are common water contaminants that impair water quality and cause diseases such as der-matitis, cancer and dysfunction of kidneys. There is therefore a need for adsorbent materials to remove dyes from water. Here a bentonite/zeolite-NaP composite was synthesized by alkaline treatment of bentonite at 150 °C for 4 h. The composite exhibits nearly cubic zeolite-NaP crystals dispersed throughout bentonite aggregates. This composite has 512 m 2 /g surface area, 387 meq/100 g cation exchange capacity and 5.4 nm average pore diameter. The composite shows high removal efficiency for methylene blue, of 94%, and Congo red, of 93%, after 720 min at an initial concentration of 5 mg/l.

Beni-Suef University Journal of Basic and Applied Sciences, 2015

Evaluation of Marwit Rod El Leqah deposit as pegmatite high purity quartz source for advanced app... more Evaluation of Marwit Rod El Leqah deposit as pegmatite high purity quartz source for advanced applications was conducted through the geological, mineralogical and geochemical studies. Elemental analysis of a representative quartz sample showed that the quartz deposits were classified as medium purity quartz with 99.575% average SiO 2 content and about 0.422% (4220 ppm) of accompanied mineral. Field study and petrography investigation using optical polarized transmitted microscope and reflected light microscope revealed that these impurities were mainly found as solid particulates of iron oxide, muscovite, rutile, orthoclase, granitic rafts, and as fluid inclusions as well. Moreover, structural undesirable trace elements were also presented in the quartz sample.

*Corresponding Author: Moaaz K. Seliem, Lecturer, Beni-Suef University, Faculty of Science, Geolo... more *Corresponding Author: Moaaz K. Seliem, Lecturer, Beni-Suef University, Faculty of Science, Geology Department, Egypt. 4423 SYNTHESIS OF NA-A ZEOLITES FROM NATURAL AND THERMALLY ACTIVATED EGYPTIAN KAOLINITE: CHARACTERIZATION AND COMPETITIVE ADSORPTION OF COPPER IONS FROM AQUEOUS SOLUTIONS Moaaz K. Seliem*, E.A. Mohamed, A.Q. Selim, M. G. Shahien and Mostafa R. Abukhadra Beni-Suef University, Faculty of Science, Geology Department, Egypt.

Applied Clay Science, 2011

This study investigated the adsorption of toluene as a non-ionic organic contaminant by organosil... more This study investigated the adsorption of toluene as a non-ionic organic contaminant by organosilicas and organo-clay minerals. Different organic surfactants were used to prepare a variety of MCM-41 molecular sieves at room temperature while cetyltrimethylammonium (CTMA) bromide was used to synthesize MCM-48 mesoporous material under hydrothermal conditions. Organo-clay minerals were synthesized under hydrothermal conditions using synthetic low-charge Na-fluorophlogopite micas with CTMA bromide as organic surfactant. All synthetic organosilicas and organo-clay minerals, the latter including those procured from two commercial sources were characterized by powder X-ray diffraction (XRD) and their toluene sorption properties were investigated. Among organosilicas, MCM-48 exhibited the highest distribution coefficient (Kd) value of toluene (95 ± 9 L/kg). An organo-clay mineral, Nanomer® PGW montmorillonite modified with CTMA bromide (Nanomer® 1.28E) showed the maximum Kd value (345 ± 22...

Construction and Building Materials

This work is the first attempt to study the possibility of incorporating three different types of... more This work is the first attempt to study the possibility of incorporating three different types of Egyptian serpentine aggregates (antigorite, lizardite and chrysotile) with different serpentinization grades as fine and coarse aggregates for normal concrete production. The results of physical and mechanical tests for each type of aggregate were compared to the others. In addition, the effect of serpentinization grade on their mineralogical composition, physico-mechanical and morphological properties of was evaluated and compared. The results were analyzed by using sophisticated tools such as X-ray diffraction, thermogravimetry/ differential thermogravimetry and scanning electron microscopy. The results revealed that the physical, mechanical and microstructural properties of serpentine-based concretes were negatively influenced by the progress of serpentinization and deformation processes. The antigorite aggregate showed the lowest serpentinization grade compared to the others (i.e. l...

Separation and Purification Technology

ABSTRACT

Applied Clay Science, 2010

Mn-kaolinite containing both Mn and Al in the octahedral sheet was prepared under hydrothermal co... more Mn-kaolinite containing both Mn and Al in the octahedral sheet was prepared under hydrothermal conditions of 100–200°C for 6–96h by using Al-nitrate, Mn-carbonate, silicic acid and aqueous solutions of NaOH or KOH. The synthetic phases were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and X-ray Absorption Near Edge Structure (XANES) spectroscopy. The results showed

Materials Research Innovations, 2010

ABSTRACT Mesoporous MCM-41 silica and rice husk composites were synthesised under hydrothermal co... more ABSTRACT Mesoporous MCM-41 silica and rice husk composites were synthesised under hydrothermal conditions using cetyltrimethylammonium bromide (CTAB) as an organic template, aqueous ammonia solution (NH4OH) and rice husk, the latter as a silica source and substrate for the deposition of MCM-41. Both untreated and carbonised rice husks were used for preparing composites at a temperature of 100–120°C for 24–48 h. The as synthesised composites or hybrid materials were characterised by using XRD and SEM and they were found to be useful for the uptake of perchlorate. These composites could be used to separate perchlorate from solutions in column operation without the necessity for their pelletisation because the rice husk substrates are several millimetres in size.

Applied Clay Science, 2013

ABSTRACT

Developments in Precambrian …, 2004

Ophiolites of mid-Neoproterozoic age are abundant in the Arabian-Nubian Shield (ANS) of NE Africa... more Ophiolites of mid-Neoproterozoic age are abundant in the Arabian-Nubian Shield (ANS) of NE Africa and Arabia. ANS ophiolites range in age from 690 to 890 Ma and litter a region that is 3000 km N-S and > 1000 km E-W. In the northern ANS, ophiolites occur as nappe complexes marking suture zones between terranes. Although dismembered and altered, all of the diagnostic components of ophiolites can be found: harzburgite, cumulate ultramafics, layered as well as higher level gabbro and plagiogranite, sheeted dikes, and pillowed basalt. Allochthonous mafic-ultramafic complexes in the southern ANS, in Ethiopia and Eritrea, are interpreted as ophiolites, but are more deformed and metamorphosed than those in the north. Reconstructed ophiolitic successions have crustal thicknesses of 2.5 to 5 km. The ANS ophiolitic mantle was mostly harzburgitic, containing magnesian olivines and spinels that have compositions consistent with extensive melting. Cr# for spinels in ANS harzburgites are mostly > 60, comparable to spinels from modern forearcs and distinctly higher than spinels from mid-ocean ridges and backarc basin peridotites. ANS ophiolites are often associated with a thick (1-3 km) sequence of cumulate ultramafic rocks, which define a transition zone between seismic and petrologic Mohos. These cumulates are dominated by dunite, with subordinate pyroxene-rich lithologies. Cumulate ultramafics transition upwards into layered gabbro. Several crystallization sequences are inferred from ANS transition zones and cumulate gabbro sections. In all samples studied, olivine and spinel crystallized first, followed (in order of decreasing abundance) by cpx-plag, cpxopx-plag, and opx-cpx-plag. ANS ophiolitic lavas mostly define a subalkaline suite characterized by low K and moderate Ti contents, that has both tholeiitic and calc-alkaline affinities and includes a significant, although subordinate, amount of boninites. The lavas are fractionated (mean Mg# = 55) but have higher abundances of Cr (mean = 380 ppm) and Ni (mean = 135 ppm) than would be expected for such a low Mg#. The ANS ophiolitic lavas include both LREE-depleted and LREE-enriched varieties, but as a group are slightly

Raw kaolinite was used as a precursor for several types of modified kaolinite. The modification p... more Raw kaolinite was used as a precursor for several types of modified kaolinite. The modification processes included modification by sodium hydroxide, sodium phosphate, sodium sulfate, CTAB, and sodium acetate. The structural, morphological, and chemical properties of raw kaolinite and the modified products were evaluated using XRD, SEM, TEM, and FT-IR analyses. The modified products were used as adsorbent materials for acidic Congo red dye from aqueous solutions. The adsorption processes were evaluated as a function of reaction time, initial dye concentration, and adsorbent masses. Phosphate-modified kaolinite achieved the best removal results followed by sulfate-modified kaolinite and kaolinite sample modified by CTAB. Kinetic studies indicated that the adsorption equilibrium was obtained after 360 min for the samples, which were modified by NaOH and CTAB, whereas the modified samples that were treated by phosphate, sulfate and, acetate achieve the equilibrium after 240 min. The adsorption by all the products is of chemical nature occurs through energetically heterogeneous surfaces and fitted well with pseudo-second order kinetic model. The equilibrium studies revealed that the adsorption using kaolinite modified by sodium hydroxide, sodium phosphate, and sodium sulfate occurs in monolayer form and represented well by Langmuir model. The estimated q max values are 136.98, 149.25, and 135.13 mg/g for the three products in order. The uptake using modified kaolinite by CTAB and sodium acetate shows more fitting with Tamkin and Freundlich isotherm models rather than with Langmuir model. Graphical Abstract Kaolinite sample was modified by organic and inorganic salts to enhance its adsorption properties. Modified kaolinite samples exhibit changes in the structural and morphological features. The modified samples showed high adsorption capacity than raw kaolinite. Highlights ● Kaolinite was modified by several inorganic and organic salts. ● Effect of modification and the structural and morphological features was investigated. ● The adsorption behavior of the modified products for Congo red dye was addressed. ● The change in the adsorption behavior was studied through kinetic and isotherm studies.

This paper aims to evaluate and upgrade the quality of quartz mining by-products through acid lea... more This paper aims to evaluate and upgrade the quality of quartz mining by-products through acid leaching process. The quartz samples were collected as gold mine by-products from El Sid-Fawakhir gold mine, Qift-Quseir, Eastern Desert, Egypt and characterized using XRF and polarized transmitted optical microscope. The present magnetic mineral impurities were detected using Frantz Isodynamic Tester. Suitability of acid leaching utilizing oxalic acid as an efficient technique for considerable reduction of the associated impurities was evaluated based on Response Surface methodology and face centered central composite design (CCD). The quartz sample was classified as low-quality quartz with low silica content (99.3%) which can't match the requirements of wide range of applications. The main detected impurities are muscovite, biotite, sericite, pyrite and iron oxide. The present magnetic impurities represent about 2.72% of the total sample. The leaching process at the optimum conditions of temperature, time and oxalic acid concentration removes ∼ 36% of the iron. This associated with a clear reduction of other magnetic impurities and noticeable enhancing in the silica content to about 99.56%. Magnetic purification followed by oxalic acid leaching for the quartz samples give better results as the iron content was reduced to about 0.001% and the silica content increased to about 99.9% which match the specifications of most of the typical high technical applications.

From the second order polynomial model, the predicted optimum conditions for maximum removal of s... more From the second order polynomial model, the predicted optimum conditions for maximum removal of safranin (100%) are 365 min contact time, 0.3 g dose, 5 g/l NaCl and pH 6 at initial concentration 127 mg/l.

Refined natural Fe-chromite was characterized by XRD, FT-IR, reflected polarized microscope, XRF ... more Refined natural Fe-chromite was characterized by XRD, FT-IR, reflected polarized microscope, XRF and UV spectrophotometer. Photocatalytic degradation and photo-Fenton oxidation of Congo red dye by Fe-chromite was investigated using 1 mL H 2 O 2. The degradation of dye was studied as a function of illumination time, chromite mass, initial dye concentration, and pH. Fe-chromite acts as binary oxide system from chromium oxide and ferrous oxide. Thus, it exhibits photocatalytic properties under UV illumination and photo-Fenton oxidation after addition of H 2 O 2. The degradation in the presence of H 2 O 2 reached the equilibrium stage after 8 h (59.4%) but in the absence of H 2 O 2 continued to 12 h (54.6%). Photocatalytic degradation results fitted well with zero, first order and second order kinetic model but it represented by second order rather than by the other models. While the photo-Fenton oxidation show medium fitting with the second order kinetic model only. The values of kinetic rate constants for the photo-Fenton oxidation were greater than those for the photocatalytic degradation. Thus, degradation of Congo red dye using chromite as catalyst is more efficient by photo-Fenton oxidation. Based on the response surface analysis, the predicted optimal conditions for maximum removal of Congo red dye by photocatalytic degradation (100%) were 12 mg/l, 0.14 g, 3, and 11 h for dye concentration , chromite mass, pH, and illumination time, respectively. Moreover, the optimum condition for photo-Fenton oxidation of dye (100%) is 13.5 mg/l, 0.10 g, 4, and 10 h, respectively.

Natural bituminous coal was used as a precursor in the synthesis of different modified products. ... more Natural bituminous coal was used as a precursor in the synthesis of different modified products. The modification of coal was performed by treating it with nitric acid (N-coal), coating its surface by zinc oxide nanoparticles (Z-coal), and converting it into porous graphite (PG). The effect of modification processes on the structures, morphologies, and optical properties was followed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR), and UV/VIS spectrophotometer analysis. The surface of N-coal grains becomes smoother than the surface of raw coal grains due to the removal of the associated impurities and the formation of nitrogen function groups. For Z-coal, the whole surface of coal grains appears to be completely covered by agglomerated ZnO nanoparticles of massive density and irregular shapes. The average crystallite size of the formed ZnO is ~22.2 nm and density of dislocations is 2.029 × 10 −3 dislocation/nm 2. Also, the removal of safranin-T dye by natural bituminous coal and its modified forms was investigated as a function of contact time, adsorbent mass, initial dye concentration , and pH value. At pH 8, the PG showed higher efficiency (96%) than Z-coal (93.5%), N-coal (74.5%), and natural coal (62%) after 2 h for 0.1 g on 100 mg/L dye. The obtained results are well fitted by pseudo-second-order kinetic than by intraparticle diffusion and Elovich kinetic models for the adsorption by N-coal, Z-coal, and PG, whereas the adsorp-tion by raw coal is well fitted with both pseudo-second-order and Elovich kinetic models. The Langmuir isotherm model fits well the equilibrium adsorption isotherm of safranin by raw coal and its modified forms. The values of maximum adsorption capacity were calculated for raw coal, N-coal, Z-coal, and PG to be 21.3, 27.4, 32.46, and 33.67 mg/g, respectively. A monolayer model with one energy and a monolayer model with two energies as advanced equilibrium models were investigated for more physical interpretation of the ad-sorption process. The calculated parameters (number of adsorbed molecules per site and number of receptor sites per unit mass) reflected the role of modification processes in the adsorption behavior of safranin.

Synthetic dyes are common water contaminants that impair water quality and cause diseases such as... more Synthetic dyes are common water contaminants that impair water quality and cause diseases such as der-matitis, cancer and dysfunction of kidneys. There is therefore a need for adsorbent materials to remove dyes from water. Here a bentonite/zeolite-NaP composite was synthesized by alkaline treatment of bentonite at 150 °C for 4 h. The composite exhibits nearly cubic zeolite-NaP crystals dispersed throughout bentonite aggregates. This composite has 512 m 2 /g surface area, 387 meq/100 g cation exchange capacity and 5.4 nm average pore diameter. The composite shows high removal efficiency for methylene blue, of 94%, and Congo red, of 93%, after 720 min at an initial concentration of 5 mg/l.

Synthetic dyes are common water contaminants that impair water quality and cause diseases such as... more Synthetic dyes are common water contaminants that impair water quality and cause diseases such as der-matitis, cancer and dysfunction of kidneys. There is therefore a need for adsorbent materials to remove dyes from water. Here a bentonite/zeolite-NaP composite was synthesized by alkaline treatment of bentonite at 150 °C for 4 h. The composite exhibits nearly cubic zeolite-NaP crystals dispersed throughout bentonite aggregates. This composite has 512 m 2 /g surface area, 387 meq/100 g cation exchange capacity and 5.4 nm average pore diameter. The composite shows high removal efficiency for methylene blue, of 94%, and Congo red, of 93%, after 720 min at an initial concentration of 5 mg/l.

Beni-Suef University Journal of Basic and Applied Sciences, 2015

Evaluation of Marwit Rod El Leqah deposit as pegmatite high purity quartz source for advanced app... more Evaluation of Marwit Rod El Leqah deposit as pegmatite high purity quartz source for advanced applications was conducted through the geological, mineralogical and geochemical studies. Elemental analysis of a representative quartz sample showed that the quartz deposits were classified as medium purity quartz with 99.575% average SiO 2 content and about 0.422% (4220 ppm) of accompanied mineral. Field study and petrography investigation using optical polarized transmitted microscope and reflected light microscope revealed that these impurities were mainly found as solid particulates of iron oxide, muscovite, rutile, orthoclase, granitic rafts, and as fluid inclusions as well. Moreover, structural undesirable trace elements were also presented in the quartz sample.