759 results on '"Mahmoud, Mohamed E."'
Search Results
302. A novel bionanocomposite from doped lipase enzyme into magnetic graphene oxide-immobilized-cellulose for efficient removal of methylene blue and malachite green dyes.
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Mahmoud, Mohamed E., El-Sharkawy, Rehab M., and Ibrahim, Ghada A.A.
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MALACHITE green , *LIPASES , *IMMOBILIZED enzymes , *POLLUTION , *GRAPHENE , *CELLULOSE , *METHYLENE blue - Abstract
[Display omitted] • A novel Magnetic graphene oxide@Cellulose@Lipase bionanocomposite is assembled. • 23.80–32.69 nm is the detected range of particle size in MGO@Cellulose@Lipase. • Factors optimization for removal of MB and MG dyes from water. • Evaluations of isotherm-kinetic models and thermodynamic parameters. • Reusability and removal of MB and MG dyes from real water samples are reported. Immobilized biosorbents with enzymes have become a topic of interest in the fields of environmental and energy science owing to their numerous advantages such as ease of separation, non-toxicity, biocompatiblity, high activity, and regeneration capability for further reuse. In this respect, lipase from Candida rugose was selected to covalently immobilize onto a supporting matrix of magnetic graphene oxide-immobilized-cellulose via glutaraldehyde to produce a magnetic bionanocomposite (MGO@Cellulose@Lipase) for the effective removal of methylene blue (MB) and malachite green (MG) from water as two target cationic pollutants. The as-synthesized bionanocomposite was characterized by various techniques to confirm the structure composition, surface morphology, thermal and magnetic properties. The SEM and HR-TEM examinations referred to good homogeneity and surface porosity with 23.80–32.69 nm as the identified particle size. Based on the BET analysis, MGO@Cellulose@Lipase exhibited a mesoporous structure with a mean pore size 11.56 nm, while the VSM results showed that the prepared bionanocomposite particles exhibited a saturation magnetization value 14.78 emu/g. To evaluate the adsorption performance of the newly designed bionanocomposite, batch adsorption experiments was carried out, under the influence and impact of various experimental controlling parameters. The adsorption correlations of MB and MG pollutants were fitted to Langmuir isotherm and pseudo -second order kinetics. The maximum computed adsorption capacity (q max) for MB and MG were 66.79 and 51.87 mg/g, respectively. Thermodynamic studies confirmed the spontaneity and the endothermic nature of the adsorption process. Moreover, excellent removal efficiency of MB and MG by MGO@Cellulose@Lipase after five consecutive adsorption–desorption cycles were confirmed as 97.43% and 87.60%, respectively. The validity and applicability of MGO@Cellulose@Lipase in removal of MB and MG pollutants from real water samples were characterized in the range 95.09–96.24% and 91.01–92.58%, respectively. Therefore, the outlined results prove that the MGO@Cellulose could be used as a promising carrier alternative for enzymes immobilization and the assembled MGO@Cellulose@Lipase bionanocomposite was also characterized as an innovative green material for solving the environmental dye pollution. [ABSTRACT FROM AUTHOR]
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- 2022
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303. Recent progress of metal organic frameworks-derived composites in adsorptive removal of pharmaceuticals.
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Mahmoud, Mohamed E., Elsayed, Sarah M., Mahmoud, Safe ELdeen M.E., Nabil, Gehan M., and Salam, Mohamed Abdel
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ORGANIC conductors , *ORGANOMETALLIC compounds , *WATER purification , *POROUS materials , *DRUGS , *DRUG disposal - Abstract
In this review article, the historical, structural and stability features of MOFs are described. Removal of most commonly used pharmaceuticals from water by the action of MOFS are also surveyed and covered. In addition, the future developments of MOFs in pharmaceuticals removal are pointed out. [Display omitted] In the last two years, excessive amounts of antibiotics and other drugs were used to minimize the symptoms of COVID-19 as well as other newly discovered modified viruses. This has daily resulted in generation and release of substantial amounts of these drugs and their metabolites to water systems as hazardous pollutants. Upon entrance of such pharmaceutical residues into water, they incorporate, interfere and uptake by a number of activities. That is why; pharmaceutical residues or pollutants in wastewater must be effectively removed before being evacuated to environments. Water treatment via adsorption technique is highly recommended due to the wide varieties of adsorbents, biosorbents and nanosorbents with their various advantages as cost effective, high surface area, excellent binding ability and superior capacity for all pollutants. Metal-organic frameworks (MOFs) and MOFs-derived composites are representing an important class of adsorbents as porous or spongy materials and thus, recently attracted research interests and industrial applications in different disciplines. The reasons for such high global performance of developed MOFs-derived composites are mainly devoted to their incorporated characteristics as high surface area, tunable micro-porosity, spongy like structures and low density-formed skeleton. Therefore, MOFs-derived composites are regarded as perfect functional porous materials for removal of various pollutants as pharmaceuticals and drugs. For this reason, the present review is devoted to cover the recent applications of modified and functionalized MOFs-derived composites for adsorbing various types of pharmaceuticals from water and wastewater. The future developments of MOFs-derived composites are also pointed out to summarize the major gaps as guidelines for progress of MOFs-derived materials in the coming few decades. [ABSTRACT FROM AUTHOR]
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- 2022
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304. Chromium speciation, selective extraction and preconcentration by alumina-functionalised 2-pyridenecarboxyladehyde thiosemicarbazone
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Mahmoud, Mohamed E., primary, Yakout, Amr A., additional, Ahmed, Somia B., additional, and Osman, Maher M., additional
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- 2008
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305. Speciation, selective extraction and preconcentration of chromium ions via alumina-functionalized-isatin-thiosemicarbazone
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Mahmoud, Mohamed E., primary, Yakout, Amr A., additional, Ahmed, Somia B., additional, and Osman, Maher M., additional
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- 2008
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306. Development of a Method for Chromium Speciation by Selective Solid Phase Extraction and Preconcentration on Alumina-Functionalized Thiosemicarbazide
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Mahmoud, Mohamed E., primary, Yakout, Amr A., additional, Ahmed, Somia B., additional, and Osman, Maher M., additional
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- 2008
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307. Improved removal and decolorization of C.I. anionic reactive yellow 145 A dye from water in a wide pH range via active carbon adsorbent-loaded-cationic surfactant.
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Mahmoud, Mohamed E., Nabil, Gehan M., El-Mallah, Nabila M., and Karar, Shimaa B.
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COLOR removal (Sewage purification) ,REACTIVE dyes ,CATIONIC surfactants ,ADSORPTION kinetics ,LANGMUIR isotherms ,FREUNDLICH isotherm equation - Abstract
A fast and highly efficient method was developed for decolorization of C.I. anionic reactive yellow 145 A dye from wastewater under a wide pH range (1.0–13.0) using a loaded cationic surfactant on the surface of an active carbon adsorbent (HTAB-AC). The efficiency of dye removal by the proposed adsorbent was studied by the batch equilibrium technique under the influence of various controlling experimental factors such as adsorbent dosage, contact time, and initial dye concentration. The determined percentage removal values of reactive yellow 145 A dye by (HTAB-AC) adsorbent in the examined solutions were found 92.5–99.6, 90.7–98.1, and 88.5–96.9% for 120, 150, and 180 mg L−1solutions, respectively. The equilibrium of removal (93.0–96.0%) was established at 20.0 min of shaking time. The effects of other system variables were evaluated and the adsorption behavior was investigated by the Langmuir and Freundlich models. Adsorption kinetic data were tested using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. Successful removal (90.2–97.6%) was accomplished in the presence of various pH values from real industrial wastewater samples. [ABSTRACT FROM PUBLISHER]
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- 2015
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308. ANTIBACTERIAL ACTIVITY OF FUROQUINOLONE ALKALOIDS AGAINST POTATO SOFT ROT BACTERIUM, Erwinia carotovora FROM Ruta chalepensis LEAVES
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Emam, Ahmed M., primary and Mahmoud, Mohamed E., additional
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- 2005
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309. Pre-Concentration of Cadmium, Mercury and Lead from Natural Water Samples by Silica Gel Functionalized Purpald as a New Chelating Matrix for Metal Sorption
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Mahmoud, Mohamed E., primary and Al-Saadi, Mohammed S. M., additional
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- 2005
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310. Characterization of Surface Modification, Thermal Stability, and Metal Selectivity Properties of Silica Gel Phases‐Immobilized Dithiocarbamate Derivatives
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Mahmoud, Mohamed E., primary, El‐Essawi, Mohyi M., additional, and Fathallah, Eiman M. I., additional
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- 2004
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311. Comparative Study of the Reactivity and Selectivity Characteristics of Three Silica Gel Phases—Immobilized‐8‐Hydroxyquinoline for Separation and Pre‐concentration of Chromium (III) from Water Samples
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Mahmoud, Mohamed E., primary and Soliman, Ezzat M., additional
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- 2003
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312. Correction to: Functional surface homogenization of nanobiochar with cation exchanger for improved removal performance of methylene blue and lead pollutants
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Mahmoud, Safe ELdeen M. E., Ursueguia, David, Mahmoud, Mohamed E., Abdel-Fattah, Tarek M., and Díaz, Eva
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- 2023
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313. COMPARISON OF METAL SORPTION PROPERTIES OF THREE SILICA GEL PHASES—PHYSICALLY ADSORBED AND CHEMICALLY IMMOBILIZED- 1-AMINOANTHRAQUINONE
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Mahmoud, Mohamed E., primary
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- 2002
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314. STUDY OF THE SELECTIVITY CHARACTERISTICS INCORPORATED INTO PHYSICALLY ADSORBED ALUMINA PHASES. II. MERCAPTONICOTINIC ACID AND POTENTIAL APPLICATIONS AS SELECTIVE STATIONARY PHASES FOR SEPARATION, EXTRACTION, AND PRECONCENTRATION OF LEAD(II) AND COPPER(II)
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Mahmoud, Mohamed E., primary
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- 2002
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315. Reactivity of Thioglycolic Acid Physically and Chemically Bound to Silica Gel as New Selective Solid Phase Extractors for Removal of Heavy Metal Ions From Natural Water Samples
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Soliman, Ezzat M., primary, Mahmoud, Mohamed E., additional, and Ahmed, Salwa A., additional
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- 2002
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316. Microwave adsorption of lead from water using lanthanum iron sulfide nanocomposite.
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Abdelwahab, Mohamed S. and Mahmoud, Mohamed E.
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LEAD removal (Water purification) , *IRON sulfides , *WATER use , *LANTHANUM , *NANOCOMPOSITE materials , *ADSORPTION isotherms - Abstract
A novel, quick approach to the synthesis of the monoclinic lanthanum iron sulfide La 32.66 Fe 11 S 60 nanocomposite was employed for water contamination remediation for the first time. One of the most harmful contaminants in the water is lead. La 32.66 Fe 11 S 60 nanocomposite is utilized to remove lead from water by adsorption under the pH, contact time, sorbent quantity, ion concentration of metal, and ion interference. The produced nanocomposite La 32.66 Fe 11 S 60 has been identified using scanning electron microscopic (SEM) and X-ray diffraction (XRD). The highest metal capacity was achieved at pH 5 and 20 s for the lead with 2450 μmol g−1. Kinetic analysis and adsorption isotherm analysis shows were studied in this work. • Preparation of La 32.66 Fe 11 S 60 nanocomposite al low temperature comparing with other synthesis methods. • Adsorption of Pb(II) from water using La 32.66 Fe 11 S 60 nanocomposite. • Adsorption process utilized rapid and efficient microwave irridiation technique. • Factor optimization for uptake of Pb(II) with La 32.66 Fe 11 S 60 nanocomposite. • Determination of kinetic and adsorption isotherm models. [ABSTRACT FROM AUTHOR]
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- 2022
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317. Synthesis, characterization and structure effects on selectivity properties of silica gel covalently bonded diethylenetriamine mono- and bis-salicyaldehyde and naphthaldehyde Schiff,s bases towards some heavy metal ions
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Soliman, Ezzat M, primary, Mahmoud, Mohamed E, additional, and Ahmed, Salwa A, additional
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- 2001
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318. Tandem mass spectrometry of some nitropyridylaryl sulfides
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Saad, Esmat F., primary, El-Hegazy, Fatma El-Zahraa M., additional, Mahmoud, Mohamed E., additional, and Hamed, Ezzat A., additional
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- 2000
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319. Mass Spectral Study of Some Phenyl-mono and Dinitropyridyl Sulfide, Ether, Amine and Sulfone Derivatives
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El-Hegazy, Fatima El-Zahara M., primary, Mahmoud, Mohamed E., additional, Saad, Esmat F., additional, and Hamed, Ezzat A., additional
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- 1997
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320. Comparison of Metal Uptake Properties of Silica Gel-Bound Ion Exchangers and Some Amine Derivatives
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Mahmoud, Mohamed E., primary
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- 1996
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321. Studies of hydrogen/deuterium exchange of monodeuteriophenol in fused-silica capillary columns using gas chromatography-mass spectrometry
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Mahmoud, Mohamed E., primary
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- 1996
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322. Adjusted pH for the Selective Separation of Cadmium from Lead by Nano-Active Silica-Functionalized-[Bmim Tf 2 N ] Ionic Liquid.
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Mahmoud, Mohamed E. and Al-bishri, Hassan M.
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HYDROGEN-ion concentration , *SEPARATION (Technology) , *CADMIUM , *LEAD , *SILICA , *IONIC liquids , *METAL ions , *AQUEOUS solutions - Abstract
A method is described for the selective separation and extraction of cadmium-lead from aqueous solutions by tuning the pH value between 1.0 and 7.0. A modified nano-active silica sorbent was loaded with 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide hydrophobic ionic liquid, [Bmim+Tf2N−] and used in this work. The pH value was found to play a significant role in the sorption capacity of Cd(II) and Pb(II). In pH 1.0, the metal capacity values were characterized as 1.40 and 0.30 mmol g−1for Cd(II) and Pb(II), respectively. In pH 7.0, Cd(II) and Pb(II) switched their capacity values to 0.65 and 1.00 mmol g−1, respectively. An anion exchange mechanism was proposed in solution with pH 1.0 for exchange of chloroanionic cadmium species by [Tf2N−]. The sorptive separation processes of Cd(II) and Pb(II) were studied and evaluated under the influence of various controlling factors. The potential applications of modified nano-silica sorbent for selective sorptive removal and separation of Cd(II) from Pb(II) in water samples was successfully accomplished by adjusting the pH value of the contact solution between 1.0 and 7.0. The results of this study indicated an efficient extraction behavior of the two examined metal ions. [ABSTRACT FROM AUTHOR]
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- 2013
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323. High performance SiO2-nanoparticles-immobilized-Penicillium funiculosum for bioaccumulation and solid phase extraction of lead
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Mahmoud, Mohamed E., Yakout, Amr A., Abdel-Aal, Hany, and Osman, Maher M.
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PENICILLIUM , *BIOACCUMULATION , *SOLID phase extraction , *SILICA , *NANOPARTICLES , *HYDROGEN-ion concentration , *PHASE equilibrium , *SURFACE chemistry - Abstract
Abstract: Novel biosorbent systems were designed, investigated and implemented for bioaccumulation of Pb(II) from aqueous solutions. These are based on the combination of SiO2-nanoparticles (N-Si) with Penicillium funiculosum fungus (Pen) for the formation of (N-Si-Pen) as well as heat inactivated Penicillium funiculosum (Pen). The SiO2-nanoparticles were also investigated as a solid sorbent phase. Surface characterization and immobilization were examined and confirmed by using FT-IR and SEM analysis. A batch equilibrium technique was used to follow-up the adsorption processes of lead under the effect of pH, contact time, sorbent dosage and initial metal concentration. The maximum capacity values were 1200.0 and 1266.7μmolg−1 for (Pen) and (N-Si-Pen), respectively at pH 5. Sorption equilibria were established in ∼20min and their data were well described by Langmuir, Freundlich and Dubinin–Radushkevich models. The potential applications of these biosorbents for extraction of Pb(II) from real samples contaminated with lead, were successfully accomplished. [Copyright &y& Elsevier]
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- 2012
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324. Surface loaded 1-methyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM + Tf 2 N − ] hydrophobic ionic liquid on nano-silica sorbents for removal of lead from water samples
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Mahmoud, Mohamed E.
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LEAD removal (Water purification) , *IMIDAZOLES , *SURFACE chemistry , *IONIC liquids , *HYDROPHOBIC surfaces , *SILICA , *SORBENTS , *SCANNING electron microscopy , *SOLID phase extraction - Abstract
Abstract: This paper demonstrates, for the first time, that 1-methyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM + Tf 2 N − ] hydrophobic ionic liquid can be potentially used as an excellent medium for solid phase extraction of Pb(II) from water matrices. In this work, [EMIM + Tf 2 N − ] was directed to synthesize two newly modified nano-silica sorbents. The first modified sorbent was based on surface derivatization via physical adsorption of [EMIM + Tf 2 N − ] onto active nano-silica particles (10–20nm) for the formation of [NSi-OH-EMIM + Tf 2 N − ]. The second sorbent was prepared by the direct reaction of [EMIM + Tf 2 N − ] with amino modified nano-silica particles for the preparation of [NSi-NH 2 -EMIM + Tf 2 N − ]. Surface modification of nano-silica particles was characterized and confirmed by surface coverage determination as well as instrumental analysis by using a scanning electron microscope (SEM), FT-IR and thermal analysis. The capability of newly modified nano silica sorbents for extraction of lead (II) without the need for a partition chelating intermediate was studied and optimized under different controlling variables including the effect of Pb(II) concentration, sorbent dose, pH of contact medium, shaking time, interfering anions and cations. The potential applications of [NSi-OH-EMIM + Tf2N−] and [NSi-NH 2 -EMIM + Tf 2 N − ] for solid phase extraction of Pb(II) from real water matrices via multi-stage micro-column separation were also studied and evaluated. [ABSTRACT FROM AUTHOR]
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- 2011
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325. Recent advances in adsorptive removal and catalytic reduction of hexavalent chromium by metal–organic frameworks composites.
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Mahmoud, Mohamed E., Elsayed, Sarah M., Mahmoud, Safe ELdeen M.E., Aljedaani, Reham O., and Salam, Mohamed Abdel
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HEXAVALENT chromium , *HEAVY metals , *CATALYTIC reduction , *METAL-organic frameworks , *TRANSITION metal ions , *CHROMIUM ions , *POROUS materials , *PHOTOREDUCTION - Abstract
[Display omitted] • Brief history and definition of metal organic frameworks (MOFs). • Structural composition and combination of MOFs in Cr (VI) removal. • State-of-the-art for adsorptive removal of Cr (VI) by MOFs composites. • State-of-the-art for catalytic reduction of Cr (VI) by MOFs composites. • Future in-depth understanding of the recent advances of MOFs composites. Metal-organic frameworks (MOFs) as porous or spongy materials have recently attracted research interests and industrial applications in different disciplines owing to the well-known characteristics as high surface area, good stability, low density-formed skeleton, spongy like structures and tunable micro-porosity. The reactivity of MOFs derivatives and composites are directly referred to their structural composition and combination of the major two constituents, namely transition metal ions and ligands. Therefore, MOFs are regarded as perfect functional porous materials for applications in removal of metal ions, catalytic reduction of toxic pollutants, sensing and detection of a number of analytes. Toxic heavy metals (Cr, As, Cd, Hg and Pb) and their species in water represent a prevalent environmental problem and their complete removal from water by conventional treatment methods is sometimes very expensive and tedious. Therefore, it is necessary to find out and design more efficient treatment techniques for removal of toxic heavy metals. Hexavalent chromium is a highly toxic and carcinogenic species which recently attracted an increasing number of focused publications on removal process by adsorption and catalytic reductive techniques. For this reason, the present review is devoted to cover the state-of-the-art for application of modified and functionalized MOFs composites for hexavalent chromium removal in order to provide the necessary basis for future in-depth understanding of the recent advances in this field. The additional focus of this review is also extended to canvass a variety of modified MOFs composites in the photocatalytic reduction and conversion of hexavalent chromium ions (highly toxic) into trivalent chromium species (less toxic). [ABSTRACT FROM AUTHOR]
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- 2022
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326. An innovative amino-magnetite@graphene oxide@amino-manganese dioxide as a nitrogen-rich nanocomposite for removal of Congo red dye.
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Mahmoud, Mohamed E., Amira, Mohamed F., Azab, Mayar M.H.M., and Abdelfattah, Amir M.
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CONGO red (Staining dye) , *IRON oxides , *NANOCOMPOSITE materials , *DYES & dyeing - Abstract
Design and assembly of a novel nanocomposite with efficient incorporated functional groups as well as superior adsorption behavior is a challenging aspect and generally aimed in the research and application fields which are focused on removal of organic, inorganic and biological pollutants. Appreciable amounts of colored wastewater are produced due to the existence of some dyes in water even at very low concentration levels which are known as highly toxic and undesirable pollutants. Therefore, the current study is devoted to assemble a novel nanocomposite for removal Congo red (CR) dye based on the intercalation of graphene oxide (GO) with amino-nanomagnetite (Fe 3 O 4 -NH 2) and amino-nanomanganese dioxide (MnO 2 -NH 2) for the fabrication of NH 2 -Fe 3 O 4 -GO-MnO 2 -NH 2 by microwave assisted synthesis technique. The as-prepared NH 2 -Fe 3 O 4 -GO-MnO 2 -NH 2 nanocomposite was explored for removal of Congo red (CR, anionic dye) from aqueous matrices. The produced NH 2 -Fe 3 O 4 -GO-MnO 2 -NH 2 along with its constituent counterparts was investigated by FT-IR, SEM, BET, XRD and TGA for characterization and structure confirmation. Experimental studies were performed to figure out the impact of pH and CR dye was found to reach the maximum removal efficiency at pH 2. The variation in NH 2 -Fe 3 O 4 -GO-MnO 2 -NH 2 dosage, shaking time, temperature and initial dye concentration were also optimized to achieve the maximum removal percentages of CR. The best fitting of kinetic model was referred to pseudo -second order. The linear and nonlinear isotherm models to evaluate the CR removal performance by NH 2 -Fe 3 O 4 -GO-MnO 2 -NH 2 were examined and found to best fitted to Langmuir model. Thermodynamic parameters, viz., ΔHo, ΔGo, and ΔSo were also estimated to confirm spontaneous and endothermic adsorption behaviors. Excellent CR dye extraction percentages (96–100%) were achieved from various water samples by applying the optimum conditions. Consequently, NH 2 -Fe 3 O 4 -GO-MnO 2 -NH 2 nanocomposite is believed to exhibit high potential in water remediation for dye removal. [Display omitted] • Design and microwave assembly of a novel NH 2 -Fe 3 O 4 -GO-MnO 2 -NH 2 nanocomposite • High surface reactivity and characteristics of NH 2 -Fe 3 O 4 -GO-MnO 2 -NH 2 • Optimum removal of Congo red (CR) dye at pH 2 • Best fitting to pseudo -second order kinetics and Langmuir model • Excellent CR dye extraction percentages (96–100%) from tap, sea and wastewater [ABSTRACT FROM AUTHOR]
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- 2022
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327. Hydrogen—deuterium exchange in fused-silica capillary columns
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Mahmoud, Mohamed E., primary, Moussa, Adel M., additional, Forsyth, David A., additional, and Vouros, Paul, additional
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- 1991
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328. Decorated Mn-ferrite nanoparticle@Zn–Al layered double hydroxide@Cellulose@ activated biochar nanocomposite for efficient remediation of methylene blue and mercury (II).
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Mahmoud, Mohamed E., El-Bahy, Salah M., and Elweshahy, Shimaa M.T.
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METHYLENE blue , *MERCURY , *BIOCHAR , *NANOCOMPOSITE materials , *LAYERED double hydroxides , *ADSORPTION isotherms , *ADSORPTION kinetics - Abstract
[Display omitted] • Powerful magnetic nanocomposite MnFe 2 O 4 @Zn-Al LDHs@Cel@AGB was prepared. • A multi-application in removal of cationic pollutants as Hg(II) and MB-dye. • Excellent removal efficiency from various water matrices. • Several acting adsorption mechanisms in the removal of Hg(II) and MB-dye. • Batch kinetic and adsorption equilibrium isotherm were discussed. An innovative magnetic nanocomposite was designed and fabricated by the functionalization and support of magnetic Mn-ferrite nanoparticle (MnFe 2 O 4) with layered double hydroxide (Zn-Al LDHs) on cellulose and activated grapes stalks-derived biochar (AGB) (MnFe 2 O 4 @Zn-Al LDHs@Cel@AGB), to incorporate active functionalities and fantastic features with the aim to explore its feasibility for removal of harmful cationic species as methylene blue dye (MB) and mercury ions from wastewater. Structural, composition, morphological, surface area, adsorption performance of the fabricated nanocomposite toward both MB and Hg(II) and reusability were also investigated. The results referred that 10 mg of the nanocomposite exhibited 97.4% and 84.0 % removal efficiency of 10 mgL-1 MB dye and 0.1 mol L-1 Hg(II) at 25 and 30 min contact times, respectively. Adsorption isotherms and kinetics of the two pollutants (MB and Hg(II)) were both governed by the pseudo -second-order equation with possible participation of intraparticle diffusion mechanism. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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329. Ceramic tiles doped with lead oxide nanoparticles: Their fabrication, physical, mechanical characteristics and γ-ray shielding performance.
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Mahmoud, Mohamed E., El-Khatib, Ahmed M., Halbas, Asmaa M., and El-Sharkawy, Rehab M.
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CERAMIC tiles , *LEAD oxides , *ATOMIC number , *MASS attenuation coefficients , *THERMOGRAVIMETRY , *FLEXURAL strength , *OXIDE ceramics - Abstract
Novel ceramic tile/lead oxide nanocomposites were designed and assembled based on doping standard ceramic tiles with lead oxide nanoparticles to serve as promising alternative candidates for γ-ray shielding. Various techniques were used to examine the structural properties of the newly formed lead oxide nanoparticles-doped ceramic tile composites including Fourier transform infrared spectrophotometer (FT-IR), X-ray diffraction (XRD), Energy dispersive X-ray (EDX), Thermal gravimetric analysis (TGA), and Field emission-transmission electron microscope (FE-TEM). The main parameter tested in order to characterize the mechanical properties of the newly formed nanocomposites was the modulus of rupture. Since the doping material used in this study was lead oxide nanoparticles, it was found that as its content increased in the ceramic body from 0.0 to 10.0 wt%, the modulus of rupture increased from 1.753 ± 0.07 to 2.674 ± 0.11 MPa, respectively. The curvature of the tiles' edges, the percentage of water adsorption, and their bulk density were among the physical properties examined. The mass attenuation coefficients of the tested samples were evaluated at different γ-ray photon energies (from 59.53 to 1332.50 keV), in terms of the weight percentage of lead oxide nanoparticles. To confirm the γ-rays shielding capabilities of assembled nanocomposites, other shielding parameters were computed, including the mean free path, the effective atomic number, the half value layer, and the effective electron density. It was found that the ceramic tile containing 10.0 wt% lead oxide nanoparticles had the highest value of mass attenuation coefficient, effective atomic number, and effective electron density and the smallest value of half value layer and mean free path, with respect to all studied nanocomposites. This results proved that as the lead oxide nanoparticles content of ceramic-tile nanocomposites increased (from 0.0 to 10.0 wt%), so did their γ-ray shielding ability. Finally, it can be concluded that ceramic tile-loaded-lead oxide nanoparticles exhibited significant improvements in the γ-rays shielding parameters compared to that filled with bulk lead oxide under the same weight percentage. • Incorporation of PbO NPs with different wt% in ceramic tiles. • The modulus of rupture values are ranged between 1.753 ± 0.07 and 2.674 ± 0.11 MPa. • Water adsorption percentages are decreased from 18.98% to 17.60%. • The bulk densities are increased from 2.09 ± 0.75 to 3.06 ± 0.38 g/cm3. • The assembled ceramic tiles exhibited better γ-rays shielding than standards. [ABSTRACT FROM AUTHOR]
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- 2021
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330. Doping starch-gelatin mixed hydrogels with magnetic spinel ferrite@biochar@molybdenum oxide as a highly efficient nanocomposite for removal of lead (II) ions.
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Mahmoud, Mohamed E., Abouelanwar, Magda E., Mahmoud, Safe ELdeen M.E., and Salam, Mohamed Abdel
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LEAD ,HYDROGELS ,NANOCOMPOSITE materials ,SPINEL ,IONS ,OXIDES ,STARCH - Abstract
Hydrogels and mixed hydrogels are 3D-hydrophilic polymeric structures with high porosity, soft consistency and excellent absorbing capability of large amounts of water and organic/inorganic pollutants. Therefore, the present work is aimed to graft starch-gelatin mixed hydrogels with magnetic spinel ferrite@biochar@molybdenum oxide to produce a novel nanocomposite (MoO 3 /MSB@CoFe 2 O 4 @Gel/Starch) with high Pb(II)uptake efficiency. The nanocomposite was assembled from MoO 3 , super magnetic CoFe 2 O 4 , waste mallow stems biochar (MSB) and gelatin-esterified starch mixed hydrogels (Gel/Starch) and characterized by FT-IR, EDX, XRD, SEM and XPS techniques. The EDX analysis of nanocomposite referred to existence of C, O, Na, N, Mo, Fe and Co with 26.68%, 29.44%, 4.55%, 3.48%, 19.72%, 10.39% and 5.74%, respectively. The swelling properties of MoO 3 /MSB@CoFe 2 O 4 @Gel/Starch produced 438% maximum swelling. The average size (27.66 nm) of nanocomposite was estimated from the XRD analysis. The maximum adsorption capacities of Pb(II) onto hydrogels were 2075, 4375 and 5000 μmol g
−1 as optimized and established using 20 mg and 40 min reaction time by 0.05, 0.1 and 0.15 mol L−1 Pb(II) ions, respectively. The XPS analysis referred to a peak at BE 138.42 eV corresponding to Pb 4 f as the main product for adsorption of Pb(II). The kinetics and adsorption isotherm models referred to a combination of chemi-physi-sorption processes. The kinetic analysis and the mechanisms for removal of Pb(II) and conversion into Pb(0) were explored and characterized in this study based on the XPS analysis. The reusability test of MoO 3 /MSB@CoFe 2 O 4 @Gel/Starch mixed hydrogels-loaded-Pb(II)/Pb(0) was investigated and referred to a slight loss (~ 2%) after five continuous recycles. [Display omitted] • A novel nanocomposite of MoO 3 -biochar- CoFe 2 O 4 -gelatin/starch mixed hydrogel. • EDX-XRD-XPS-SEM-FTIR techniques were employed for characterization. • MoO 3 /MSB@CoFe 2 O 4 @Gel/Starch hydrogel confirmed a maximum swelling (438%). • Removal optimization of Pb(II) ions via successive adsorption and reduction. • 20 mg hydrogel and 40 min produced 5000 μmol g−1 capacity for 0.15 mol L−1 of Pb(II). [ABSTRACT FROM AUTHOR]- Published
- 2021
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331. Novel supramolecular network of graphene quantum dots-vitamin B9-iron (III)-tannic acid complex for removal of chromium (VI) and malachite green.
- Author
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Mahmoud, Mohamed E., Fekry, Nesma A., and Abdelfattah, Amir M.
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MALACHITE green , *TANNINS , *FOLIC acid , *QUANTUM dots , *CHROMIUM , *POLLUTANTS - Abstract
[Display omitted] • A novel (GQDs@FA@Fe-TA) supramolecular network was fabricated with 37.57 nm. • Multipurpose application of (GQDs@FA@Fe-TA) for removal of Cr(VI) and MG dye. • Removal of Cr(VI) was optimized as 99.5% at pH 3.0 and 5 min. • Adsorption was best appropriated to pseudo -second order and Langmuir model. • Excellent Cr(VI) removal (91.2–99.4%) and MG (89.8–92.1%) from various waters. The present work is devoted to synthesize graphene quantum dots (GQDs) from waste sugarcane bagasse with average particle size 4.2 nm based on the TEM analysis. The produced GQDs were then aimed to combine with vitamin B9 (folic acid = FA) and Fe3+-tannic acid complex (Fe-TA) for the formation of a novel (GQDs@FA@Fe-TA) supramolecular network with average particle size 37.57 nm and pore diameter 38.35 nm. (GQDs@FA@Fe-TA) was evaluated as a multipurpose nanosorbent for removal of inorganic anionic (Cr(VI)) and organic cationic (malachite green, MG) pollutants from water. Cr(VI) removal was optimized as 99.5% (at pH 3.0 after 5 min), while 94.8% for MG (at pH 6.0 after 30 min). Adsorptions of both pollutants were exothermic and spontaneous and well explained with the pseudo -second order and Langmuir model. (GQDs@FA@Fe-TA) exhibited higher regeneration stability after five consecutive adsorption–desorption cycles (~2.1–4.3% loss). Finally, the potential applications of (GQDs@FA@Fe-TA) for removal of inorganic anionic and organic cationic pollutants from various water samples were 91.2–99.4% and 89.8–92.1% for Cr(VI) and MG, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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332. Efficient and ultrafast removal of Cd(II) and Sm(III) from water by leaves of Cynara scolymus derived biochar.
- Author
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Mahmoud, Mohamed E., Abou-Ali, Samir A.A., and Elweshahy, Shimaa M.T.
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ARTICHOKES , *SORPTION techniques , *BIOCHAR , *HEAVY metals , *SAMARIUM , *MICROWAVE heating , *NANOPARTICLES , *WATER pollution - Abstract
[Display omitted] • Nano Cynara scolymus derived biochar was prepared. • Factor optimization by microwave assisted sorption approach. • Superfast extraction and removal of heavy metals in 25 s. • The sorption mechanism and kinetics of Cd(II) and Sm(III) by the prepared biochar. • Reusability of Cynara scolymus derived biochar. Applicability of biochar materials in water remediation is picking up recent interests on account of their sustainability and low mass-production cost. Herein, a novel ecofriendly nanobiochar was successfully fabricated by employing discarded materials from Cynara scolymus leaves (CSL) (Artichoke) as a green renewable low-cost nanosorbent. The produced nanomaterial was employed to estimate the adsorption characteristics towards two different heavy metal cations namely; cadmium and samarium using microwave sorption technique. The chemical composition and the surface morphology of the as-prepared nanobiochar (CSL-NanoB) were determined and fully characterized by (FT-IR, SEM, XRD, TGA and EDX) analyses, which proved the uniform nanosized biochar particles (23.54–27.8 nm). Microwave-assisted sorption technique as a rapid approach was utilized and implemented to assess the influences of some critical analytical parameters on adsorption process as solution pH, nanobiochar dose, irradiation exposure time, interfering ions and initial metal ion concentrations. The optimum conditions were quantitatively estimated at pH 7.0, 25 s heating time, and 10 mg nanosorbent mass. The equilibrium uptake capacity values of Cd(II) and Sm(III) were established as 1150 and 650 μmolg−1, respectively. Metal complexation with −OH and −COOH groups and ion exchange were characterized as the participating dominant mechanisms in adsorption process. Sorption kinetics data were fitted well with pseudo -first-order and Elovich with the contribution of intra-particle diffusion in the adsorption mechanism, as well as correlated with Freundlich isotherm model. Thermodynamic parameters indicated that, the sorption process of examined metal ions on CSL-NanoB was endothermic as favored at high temperature and spontaneous in nature. Furthermore, the adsorption performance of CSL-NanoB was significantly stable and efficient after multiple regeneration process. The outlined results indicate that, the investigated CSL-NanoB is a sustainable, dynamic and affordable nanosorbent to contribute in solving water pollution problems. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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333. Immobilization of [Bmim + Tf 2 N − ] hydrophobic ionic liquid on nano-silica-amine sorbent for implementation in solid phase extraction and removal of lead.
- Author
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Al-bishri, Hassan M., Abdel-Fattah, Tarek M., and Mahmoud, Mohamed E.
- Subjects
HYDROPHOBIC surfaces ,IONIC liquids ,SILICA ,AMINES ,SORBENTS ,SOLID phase extraction ,LEAD - Abstract
Abstract: A method is described for highly efficient adsorptive removal of lead with a maximum metal capacity value of 1.300mmolg
−1 by using physically immobilized [Bmim+ Tf2 N− ] on the surface of nano-silica-amine sorbent. Lead sorption was found to be highly dependent and controlled by several experimental factors. The effect of sorbent dose played a significant role by yielding the maximum lead adsorption capacity when 100mg sorbent was used. The effect of lead concentration was examined by various adsorption isotherms. The potential applications for removal of Pb(II) were studied and the percentage recovery values were 99.0–100.0±2.0–5.0%. [Copyright &y& Elsevier]- Published
- 2012
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334. Manganese dioxide nanoparticles decorated with chitosan for effective removal of lead and lanthanum ions from water by microwave sorption technique.
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Mahmoud, Mohamed E., Ibrahim, Ghada A.A., and Abdelwahab, Mohamed S.
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SORPTION techniques , *MANGANESE dioxide , *LEAD removal (Sewage purification) , *LANTHANUM , *CHITOSAN , *MICROWAVE heating - Abstract
[Display omitted] • Preparation of MnO 2 -F-Chitosan nanocomposite via formaldehyde cross-linkage. • Removal of lead and Lanthanum ions from water. • The surface area of MnO 2 -F-Chitosan nanocomposite using the BET method 49.17 m2. g−1. • Maximum capacity of Pb(II) is 1350 µmol g−1 and La (III) as 1100 µmol g−1. • Removal of lead and Lanthanum ions from real water and wastewater samples was between 95.6–96.4% and 91.2–92.3%, respectively. In this work, a novel sorbent has assembled and explored to remove lead and lanthanum ions from water using formaldehyde as a cross-linkage between manganese dioxide chitosan for the formation of MnO 2 -F-Chitosan nanocomposite. Microwave adsorption technique used because of its high efficiency and rapidness. MnO 2 -F-Chitosan nanocomposite has a particle size 19–25 nm, and surface area using BET is 49.17 m2.g−1. The microwave sorption technique was established by monitoring the maximum capacity of Pb(II) as 1350 µmol g−1 at pH 6.0 and La (III) as 1100 µmol g−1 at pH 7. The microwave sorption was studied using the four isotherm models Langmuir, Freundlich, Temkin, and D-R models, respectively. The most suitable adsorption model is the Temkin adsorption isotherm model via uniform distribution of binding energies. Adsorption of lead and lanthanum ions is spontaneous, endothermic and ordered reactions. The lead and lanthanum ions removal from real water/wastewater samples was 95.6–96.4% and 91.2–92.3%. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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335. Self-decoration of N-doped graphene oxide 3-D hydrogel onto magnetic shrimp shell biochar for enhanced removal of hexavalent chromium.
- Author
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Mahmoud, Mohamed E., Mohamed, Asmaa K., and Salam, Mohamed Abdel
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HEXAVALENT chromium , *GRAPHENE oxide , *BIOCHAR , *SHRIMPS , *HYDROGELS , *ADSORPTION capacity , *DRINKING water - Abstract
In this work, a novel decorated and combined N-doped graphene oxide hydrogel with shrimp shell magnetic biochar (NGO3DH-MSSB) biosorbent was fabricated as an effective material for Cr(VI) removal. Three-dimensional self-assembled graphene oxide hydrogel was synthesized using nitrogen source, ethylenediamine (EDA). Characterizations of NGO3DH-MSSB biosorbent were established by FT-IR, TGA, SEM and BET, where high surface area (398.05 m2/g) compared with that of MSSB (138.64 m2/g) was characterized. The maximum achieved swelling ratio (800%) was only after 300 min. The binding mechanisms between Cr(VI) ions and NGO3DH-MSSB biosorbent were controlled by electrostatic adsorption (ion-pair), pore filling, and reduction-coordination reaction. Adsorption was described by the pseudo -second order kinetic (R2 = 0.9994, 0.9983 and 0.9992) at 10, 50 and 100 mg/L and Langmuir isotherm model (R2 = 0.9997, 0.9957 and 0.9912) at 25, 40 and 50 °C. The adsorption capacity (350.42 mg/g) was achieved at pH 1.0, using initial Cr(VI) concentration (100 mg/L) and contact time (180 min) at room temperature. NGO3DH-MSSB biosorbent could be successfully reused after eight cycles. The percentage removal of Cr(VI) were confirmed as 99.79%, 99.20% and 98.00% from tap water, sea water and wastewater, respectively. ga1 • A novel shrimp shell magnetic biochar (MSSB) was prepared. • N-doped graphene hydrogel biosorbents (NGO3DH-MSSB) was decorated. • Maximum swelling ratio (800%) was achieved after 300 min. • Factors optimization of Cr(VI) removal by NGO3DH-MSSB were monitored. • Excellent Cr(VI) removal from real samples (98.0–99.79%) was confirmed. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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336. Effects of Al2O3 and BaO nano-additives on mechanical characteristics of high-density polyethylene.
- Author
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Mahmoud, Mohamed E., Khalifa, Mohammed A., El-Sharkawy, Rehab M., and Youssef, Mahues R.
- Subjects
- *
HIGH density polyethylene , *TENSILE strength , *POLYMERIC nanocomposites , *YIELD stress , *POLYETHYLENE , *TENSILE tests - Abstract
Fabrication of polymer doped with metal oxides has been recently aimed to improve the physical, chemical, structural, morphological, thermal and mechanical characteristics. Therefore, the current study is directed to dope two nano-metal oxides into high density polyethylene (HDPE) using the roll-mixing and thermal-pressing techniques. The weight fractions of nanofillers were varied from 2.0% to 8.0% in the resulting composite. The FT-IR along with XRD and SEM were used to examine the structural properties of the new nanocomposites. Images from the scanning-electron microscopy demonstrated that Al 2 O 3 and BaO nanoparticles were properly dispersed in the HDPE's polymeric material without essential aggregations. TGA as well as DSC were used to test the effects of Al 2 O 3 -NPs and BaO-NPs incorporation on the thermal properties of HDPE. Tensile tests were carried out to detect how the mechanical behavior of the polymeric matrix was affected by the weight fraction of the nanofiller. Elastic modulus, tensile strain (extension) at yield (%), tensile stress at break, ultimate tensile strength, tensile strain (extension) at break (%), and yield stress were determined in this research. It was concluded that the elastic modulus was found to increase with increasing the nanofiller content up to 4.0 wt% for BaO-NPs and 6.0 wt% for Al 2 O 3 -NPs to reach 229% and 208% increment, respectively with respect to the hosting matrix. The values of tensile stress at break, yield stress, tensile strain (extension) at break and tensile strain (extension) at yield of the synthesized nanocomposites decreased, as the content of both fillers increased from 2.0 to 8.0 wt%. Finally, a comparison between BaO-NPs and Al 2 O 3 -NPs, when added to the HDPE matrix, showed that the BaO nanofiller led to distinct improvements in the mechanical parameters of HDPE than Al 2 O 3 -NPs, for the same weight percentage. Image 1 [ABSTRACT FROM AUTHOR]
- Published
- 2021
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337. New magnetic cellulose nanobiocomposites for Cu(II), Cd(II) and Pb(II) ions removal: kinetics, thermodynamics and analytical evaluation
- Author
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El Nemr, Ahmed, El-Assal, Amany A. M., El Sikaily, Amany, Mahmoud, Mohamed E., Amira, Mohamed F., and Ragab, Safaa
- Abstract
Magnetic cellulose nanobiocomposites have been designed and synthesized from sugarcane bagasse to develop new and adequacy adsorbents for heavy metals adsorption from water. In this study, three different ways were followed for three nanocomposites’ preparation: (1) coating Fe3O4through preparation of dissolved cellulose in (7% NaOH and 12% urea) aqueous solution (NFC1), (2) coating Fe3O4with cellulose through the co-precipitation (NFC2) and (3) crosslinking the cellulose and Fe3O4with formaldehyde (NFC3). The high-resolution transmission electron microscope (HR-TEM) images confirmed the particle size was ranged from 6 to 25 nm. The three novel nanocomposites’ characterization was accomplished by study of surface area, Fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). The sorption feature of NFC1, NFC2 and NFC3 toward Cu(II), Cd(II) and Pb(II) ions was explored using the batch equilibrium technique with various experimental controlling parameters. The efficiency of NFC1 appears to be the best for removal of Pb(II) and Cu(II) (3150 and 2150 μmol g−1) and NFC2 more adequate nanocomposite for removal of Cd(II) 800 μmol g−1. The optimum time was proceeded via fast sorption equilibrium at 5–30 min and better fitted with the pseudo-second order kinetic model. Adsorption isotherm obeys Langmuir isotherm that provides better model than the Freundlich isotherm model. According to the thermodynamic parameters, the adsorption was dominated by enthalpic rather than the entropic changes.
- Published
- 2021
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338. One-step synthesis of zero-valent Sn nanoparticles and potential microwave remediation of lead from water.
- Author
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Mahmoud, Mohamed E. and Abdelwahab, Mohamed S.
- Subjects
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LEAD in water , *NANOPARTICLES , *LEAD removal (Water purification) , *ADSORPTION isotherms , *ADSORPTION kinetics , *PASSIVATION , *LANGMUIR isotherms - Abstract
• Synthesis zero-valent Sn nanoparticles (zero-valent Sn NPS) via a simple and eco-friendly method. • Full Characterization of Zero valent Sn nanoparticles using FT-IR, SEM, TEM, TGA, and XRD. • Kinetics and Adsorption isotherm models supported with AIC were applied in this work. • Zero-valent Sn NPS was employed as an effective nano sorbent for Pb(II) with 5300 μmol/g at 20 s(s) under pH 7 technique. Nano zero-valent metals (nZVM) widely used as an adsorbent for heavy metal remediation from water. However, the disadvantages of nano zero-valent iron (nZVI) are low stability, rapid passivation, and limited mobility. Therefore, the present study aimed to synthesize stable zero-valent Sn nanoparticles(zero-valent Sn NPS) without any surface protection for water remediation of lead (II). The size of zero-valent Sn NPS were14−39 nm, with high thermal stability. The maximum metal capacity obtained from this experiment was 5300 μmol/g at 20 s under pH 7 via microwave adsorption technique, the kinetic and adsorption isotherm study supported with the Akaike Information Criterion (AIC). Kinetic study shows that zero-valent Sn NPS are undergoing pseudo-second-order, which confirms that the adsorption reaction is a chemisorption reaction. Also, adsorption isotherm data show that the adsorption process obeys the Freundlich model, which confirms the formation of a multilayer of Pb(II) over the nano sorbent surface. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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339. Decorated gelatin polymer onto copper aluminum layered double hydroxides for superior removal of Congo red: Optimization and adsorption evaluation of kinetics, isotherms, and thermodynamics.
- Author
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Nabil, Gehan M., Althomali, Raed H., and Mahmoud, Mohamed E.
- Subjects
- *
CONGO red (Staining dye) , *COLOR removal (Sewage purification) , *LAYERED double hydroxides , *POLLUTANTS , *POLLUTION , *COPPER - Abstract
• Solid-solid and microwave-assisted formation of Cu/Al-LDHs@Gltn nanobiosorbent. • The SEM analysis of Cu/Al-LDHs@Gltn confirmed particle size at 16.54 to 30.68 nm. • Confirmed optimum capture of Congo red dye pollutant (CRDP) at pH 2.0. • Two and three parameters adsorption isotherm models were evaluated. • Excellent removal efficiency of CRDP from various waters providing 90.4–95.1%. Azo-dyes are highly soluble in water and well documented by their toxic and nonbiodegradable characters and the removal of such dye pollutants from wastewater is aimed to control environmental pollution. Therefore, the current study is designed and executed to efficiently remove Congo Red dye pollutant (CRDP) as an example of azo-dye coloring materials by using a newly synthesized nanobiosorbent. The aimed Cu/Al-LDHs@Gltn nanobiosorbent was prepared by the direct combination and binding of gelatin as a sustainable biopolymeric material with copper aluminum layered double hydroxides (Cu/Al-LDHs) by using a green microwave synthesis approach. Several characterization techniques were applied to confirm the morphology and structure of Cu/Al-LDHs@Gltn. The particle size range was identified by using the SEM analysis from 16.54 nm to 30.68 nm and the EDX investigation confirmed the elemental existence of C (25.1%), O (41.9%), and N (13.5%), Al (3.2%), Cu (11.9%) and Cl (4.4%) elements. The FT-IR analysis referred to the incorporation of several surface functionalizations as –OH, COOH, metal-O and others, while the BET-surface area configuration was detected (41.35 m2 g−1). Zero-charge point of Cu/Al-LDHs@Gltn was also measured to provide (pHzpc = 6.0). The significant controlling parameters were testified to optimize the pollutant adsorption onto the aimed Cu/Al-LDHs@Gltn via batch removal experiments by using 5-15 mg/L CRDP concentrations. The optimum pH (2.0), reaction duration (35 min), dosage (15 mg) and reaction temperature (25°C) conditions were concluded. Several related models to adsorption isotherm and kinetic studies were explored. The thermodynamic parameters additionally estimated the spontaneity and the exothermal adsorptive reaction of CRDP onto Cu/Al-LDHs@Gltn. This was confirmed to afford high stability and sustainability providing successive efficiency up to 94.6%, 84.1% and 78.8% (1st cycle) and yielded 83.3%, 70.1% and 64.5% (3rd cycle) upon testifying 5, 10 and 15 mg/L CRDP concentrations, correspondingly. Cu/Al-LDHs@Gltn was finally characterized by excellent CRDP removal efficiency up to 92.1-95.1% (5 mg/L CRDP), 91.9-92.3% (10 mg/L CRDP) and 90.4-91.7% (15 mg/L CRDP) from drinking, sea and wastewaters, correspondingly. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2025
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340. Rapid and efficient removal of lead from water by α-FeOOH/Cellulose/TiO2 nanocomposite.
- Author
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Mahmoud, Mohamed E. and Abdelwahab, Mohamed S.
- Subjects
- *
LEAD in water , *ADSORPTION isotherms , *NANOCOMPOSITE materials , *DRINKING water , *MICROWAVE heating - Abstract
• Preparation of α-FeOOH and then FeOOH-Cellulose-TiO 2 hybrid nanocomposite was designed by a simple and eco-friendly method. Full Characterization of FeOOH-Cellulose-TiO 2 hybrid nanocomposite using FT-IR, SEM, TGA and XRD. • FeOOH-Cellulose-TiO 2 hybrid nanocomposite was used as adsorbent for Pb(II) from water. A comparative study between batch equilibrium method and microwave sorption technique was established under the influence of various conditional factors like pH, contact time, sorbent dose, metal ion concentration and interfering ions. • Kinetics study like pseudo -first-order, pseudo -second-order, Elovich and Intraparticle diffusion models were applied in this work. Adsorption isotherm models like Langmuir Freundlich, Temkin and D-R isotherm were applied in this work. • The maximum metal capacity values using 5 mg of FeOOH-Cellulose-TiO 2 nanocomposite was 9600 µmol.g−1 in 20 seconds by the microwave sorption technique, while that by batch equilibrium technique was characterized as 8800 µmol.g−1 at 30 min. Application on removal of Pb(II) from real water/ wastewater samples In this work, FeOOH-Cellulose-TiO 2 hybrid nanocomposite was prepared via formaldehyde crosslinker and used for lead ions, Pb(II), remediation from water. Adsorption of Pb(II) from the water done by using batch and microwave adsorption approaches. According to this work, the microwave adsorption technique showed the best adsorption efficiency. The extraction of lead (II) under microwave irradiation was accomplished via controlled parameters (pH 7 with short contact time 20 sec) and the maximum metal capacity value (9600 µmol.g−1) obtained by using 5 mg of FeOOH-Cellulose-TiO 2 nanocomposite. Kinetic model and adsorption isotherm study revealed the best fitting with Lagergren-second-order and D-R model, respectively. The efficiency of FeOOH-Cellulose-TiO 2 nanocomposite for removal of Pb(II) from tap water and wastewater was configured by using column technique and microwave technique. The highest percent removal values of Pb(II) from tap and wastewater samples were 98% and 99%, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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341. Adsorption of negatively charged food tartrazine and sunset yellow dyes onto positively charged triethylenetetramine biochar: Optimization, kinetics and thermodynamic study.
- Author
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Mahmoud, Mohamed E., Abdelfattah, Amir M., Tharwat, Rana M., and Nabil, Gehan M.
- Subjects
- *
TARTRAZINE , *BIOCHAR , *BASIC dyes , *ANALYTICAL mechanics , *ADSORPTION isotherms , *ELIMINATION reactions - Abstract
Biochars are economic and ecofriendly materials which are loaded with negative charges to afford strong binding with organic-inorganic cationic species. Thus, adsorptive removal of anionic species from aqueous matrices is difficult without charging the surface of biochars with positively charged derivatives via chemical modification reaction. In this study, corncob nanobiochar (NCB) has been prepared by pyrolysis in low oxygen atmosphere and found to attain high elimination efficiency of cationic dyes and low efficiency for removal the anionic dyes. Therefore, triethylenetetramine has been selected and allowed to bind with corncob biochar to produce (NCB-TA). The modified biochar has been additionally treated with sulfuric acid to form positively charged amine nanobiochar (NCB-TA-PC) for improving surface properties and forming versatile nanobiosorbents with efficiently elimination of hazardous anionic dyes such as tartrazine and sunset yellow. The characterization of modified biochar indicated amino functional group containing nanobiosorbent with average size (10–18 nm) to confirm the effective surface modification process. Various practical parameters were investigated for meliorating the elimination reaction of tartrazine and sunset yellow dyes from aqueous solutions. Four different kinetic models and four adsorption isotherms were examined and indicated physisorption dye elimination mechanism and the adsorption process was found to obey pseudo-second order kinetic model. High elimination percentage of tartrazine and sunset yellow from actual water samples were obtained as 93.73 and 95.42% from tap water, 94.29% and 94.52% from sea water and 93.31 and 92.06% from industrial wastewater. Unlabelled Image • Corncob nanobiochar (NCB) was prepared by pyrolysis in low oxygen atmosphere. • Positively charged amine nanobiochar (NCB-TA-PC) was synthesized. • Particle size characterization of NCB-TA-PC with average 10–18 nm • Removal of negatively charged food tartazine and sunset yellow dyes • Evaluation of various adsorption isotherm and kinetic models [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
342. Removal of uranium (VI) from water by the action of microwave-rapid green synthesized carbon quantum dots from starch-water system and supported onto polymeric matrix.
- Author
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Mahmoud, Mohamed E., Fekry, Nesma A., and Abdelfattah, Amir M.
- Subjects
- *
QUANTUM dots , *PHTHALIC acid , *QUANTUM dot synthesis , *POLYMERIC nanocomposites , *AMINOBENZOIC acids , *URANIUM , *WATER purification , *MICROWAVE heating - Abstract
• Facile hydrothermal route for synthesis of Carbon quantum dots (CQDs). • The CQDs is loaded on PAFP polymeric matrix. • High efficiency and durability of U(VI) removal by CQDs@PAFP. • CQDs@PAFP has potential for industrial practicability of U(VI) treatment. Carbon quantum dots (CQDs) are a new class of carbon nanoparticles with superior advantages as small particle size, excellent biocompatibility and low toxicity which advance their recent applications in biotechnology, bioimaging and biosensing. The use of free CQDs in water treatment is greatly rendered by their high solubility in water. Therefore, this work is aimed to rapidly synthesize CQDs in only 10 min via microwave irradiation pyrolysis of starch-water system. The maximum fluorescence emission of CQDs was detected at 526 nm throughout the excitation wavelength (390 nm). The CQDs have been targeted to occupy the surface and pores of a polymeric material based on poly(anthranilic acid-formaldehyde-phthalic acid) (PAFP) to produce a novel CQDs@PAFP nanobiosorbent. The surface area of CQDs@PAFP was detected (28.79 m2 g−1 BET) and the nanoparticle size was confirmed (TEM). The highest removals of U(VI) by CQDs@PAFP nanobiosorbent were 95.5–98.0 % for 30−90 mg L-1. The sorption mechanism was designated to the pseudo -second-order model and closely tailored with Freundlich model. CQDs@PAFP was emerged as an excellent nanobiosorbent for U(VI) removal from wastewater (97.3 %) and sea water (96.0 %). CQDs@PAFP confirmed its excellent reusablity for efficient multi- recovery of U(VI) from different water samples. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
343. Encapsulation of starch hydrogel and doping nanomagnetite onto metal-organic frameworks for efficient removal of fluvastatin antibiotic from water.
- Author
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Mohamed, Asmaa K. and Mahmoud, Mohamed E.
- Subjects
- *
METAL-organic frameworks , *MAGNETITE , *STARCH , *HYDROGELS , *STATINS (Cardiovascular agents) , *LANGMUIR isotherms , *MICROWAVE heating , *ANTIBIOTICS - Abstract
• Novel magnetic MOFs-Starch hydrogel has been synthesized. • High surface area (528.39 m2/g) of the MOFs-Starch hydrogel was confirmed. • Maximum swelling ratio (1000.0 %) of the hydrogel at pH 10, 180 min and 25 °C. • Adsorptive removal of Fluvastatin statin drug was optimized. • Adsorption was best fitted with Langmuir isotherm and pseudo -second models. Growing interests and efforts have been recently focused on design and assembly of novel hydrogel nanosorbents for removal of drugs from wastewater. Therefore, this work is aimed to immobilize and encapsulate starch hydrogel matrix onto metal organic frameworks (MOFs) and dope with nanomagnetite. The magnetic MOFs-Starch hydrogel (NFe 3 O 4 @Zn(GA)/Starch-Hydrogel) was synthesized via microwave irradiation process and characterized with high surface area (528.39 m2/g), mesoporous with pore size 2.90 nm and highly crystalline structure. The maximum swelling ratio (1000.0 %) was optimized at pH 10, 180 min and 25 °C. The validity of NFe 3 O 4 @Zn(GA)/Starch-Hydrogel for adsorptive removal of Fluvastatin statin drug provided maximum equilibrium adsorption capacity 782.05 mg g−1. The Langmuir isotherm and pseudo-second kinetics models were correlated well with the computed correlation coefficient values 0.9991 and 0.9997, respectively. The validity of NFe 3 O 4 @Zn(GA)/Starch-Hydrogel for removal of FLV statin drug from real water matrices was confirmed in the range 96.15–99.99 %. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
344. Nanoscale Pisum sativum pods biochar encapsulated starch hydrogel: A novel nanosorbent for efficient chromium (VI) ions and naproxen drug removal.
- Author
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Mohamed, Asmaa K. and Mahmoud, Mohamed E.
- Subjects
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CHROMIUM ions , *PEAS , *BIOCHAR , *STARCH , *CHROMIUM , *SURFACE area measurement , *LANGMUIR isotherms - Abstract
• N-PSPB/SHGL, a novel ecofriendly biochar-based starch hydrogel nanosorbent. • High capacities of Cr(VI) and naproxen as 420.13 and 309.82 mg/g, respectively. • Adsorption processes were fitted with various Kinetics and isotherm models. • Chromium (VI) removal mechanism was based on ion-pair formation and pore filling. • Pore filling, п-п interaction and H-bonding control the Naproxen adsorption. Assembly of novel ecofriendly and sustainable (N-PSPB/SHGL) nanosorbent was fabricated based on encapsulation of derived nanoscale spherical biochar from Pisum sativum pods (N-PSPB) with starch hydrogel (SHGL). The mass ratio between starch and N-PSPB was examined and 2% (w/w) was selected as the optimum percentage for fabrication of the assembled hydrogel. High swelling capacity was characterized by N-PSPB/SHGL nanosorbent (500.0%) at room temperature (25 °C), excellent stability for ten cycles with respect to regeneration by 0.1 mol L−1 HCl. Additionally, characterizations of N-PSPB/Starch nanosorbent were established by SEM and BET measurement to characterize surface area (226.94 m2/g) and pore volume (9.88 cm3/g). The N-PSPB/SHGL nanosorbent was subjected to extensive investigations to evaluate its efficiency for removal of naproxen drug (NAP) and chromium (VI). The Cr(VI) and NAP drug adsorptions were fitted to pseudo -second kinetic and correlated with Langmuir isotherm. The adsorption processes were spontaneous and endothermic based on thermodynamic study. [ABSTRACT FROM AUTHOR]
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- 2020
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345. Metoprolol beta-blocker decontamination from water by the adsorptive action of metal-organic frameworks-nano titanium oxide coated tin dioxide nanoparticles.
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Mohamed, Asmaa K. and Mahmoud, Mohamed E.
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METOPROLOL , *STANNIC oxide , *TITANIUM oxides , *OXIDE coating , *TIN oxides , *PHYSISORPTION - Abstract
Due to prevalent use, resistance to hydrolysis and confined human metabolism, metoprolol (METP) b-blockers are excessively detected in water effluents and therefore must be removed. Adsorption of METP onto metal-organic frameworks-nano titanium oxide coated tin dioxide (nTiO 2 @SnO 2 @Mn(5AB-HQ)) nanocomposite was monitored to examine the potential decontamination from wastewater contaminated. The nTiO 2 @SnO 2 @Mn(5AB-HQ) nanocomposite was synthesized by the reaction of 5-azobenzoate-8-hydroxyquinoline (5AB-HQ) with manganese chloride in presence of mixed metal oxides (nTiO 2 @SnO 2) under microwave heating irradiation for 3 min and effectively implemented for adsorption of METP. Excellent surface area was evident (267.75 m2g−1) and the maximum METP recoveries were 65.42, 82.55 and 95.89% using 50, 100 and 150 mg L−1, respectively. The possible interaction mechanisms are suggested to take place by both physical adsorption in the forms of electrostatic and π-π interaction as well as chemical adsorption as coordination bond formation based on the effect of solution pH and zeta potential of METP. Five kinetics models were monitored to assure adsorption fitting of METP via pseudo -second and pore film diffusion models. Seven isotherm models confirmed adsorption suitability of Langmuir and Redlich-Peterson models. Finally, the assembled nTiO 2 @SnO 2 @Mn(5AB-HQ) was confirmed as a substantially functionalized and recyclable nanocomposite to afford powerful nanomaterial for water decontamination of metoprolol b-blocker. Unlabelled Image • Assembly of novel metal organic framework, nTiO 2 @SnO 2 @Mn(5AB-HQ) • Adsorptive removal of metoprolol (METP) b-blockers • Study and optimization of the equilibrium and removal factors • Evaluations of the isotherm and kinetics models and thermodynamic parameters • Successful removal of metoprolol (METP) b-blockers from water matrices [ABSTRACT FROM AUTHOR]
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- 2020
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346. Enhanced adsorption of Levofloxacin and Ceftriaxone antibiotics from water by assembled composite of nanotitanium oxide/chitosan/nano-bentonite.
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Mahmoud, Mohamed E., El-Ghanam, Abdel Moneim, Mohamed, Rabah Hanem A., and Saad, Shaimaa R.
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CEFTRIAXONE , *ANTIBIOTICS , *SEWAGE , *ADSORPTION isotherms , *SCANNING electron microscopy , *ADSORPTION (Chemistry) , *GLUTARALDEHYDE - Abstract
A novel NBent-NTiO 2 -Chit nanocomposite has been synthesized from the crosslinking combination of nanotitanium oxide-chitosan (NTiO 2 -Chit) and nanotitanium oxide-bentonite (NTiO 2 -Bent) via formaldehyde. The characterization of NBent-NTiO 2 -Chit was confirmed by different instrumentations. The particle size (34–97 nm) and surface area (16.385 m2 g−1) were confirmed from the scanning electron microscopy and BET measurement, respectively. The FT-IR of NBent-NTiO 2 -Chit confirmed the presence of OH, N–H, Si–O–Al and Si–O–Si functional groups. Four thermal degradation steps were characterized from the TGA of NBent-NTiO 2 -Chit with a total loss = 23.514% in the temperature range 30–600 °C. The assembled nanocomposite enhanced the removal of two important classes of antibiotics including Levofloxacin (LEVO) Ceftriaxone (CFT) in the forms of Fluoroquinolone and Cephalosporin, respectively. The various factors that affected the percentage of extraction were applied and optimized such as pH, dosage, initial concentration of LEVO and CFT, contact time and interfering ions. Maximum percentage values of 90.2% (pH 4) and 93.5% (pH 5) for LEVO and CFT, respectively, were achieved at 10 min. The enhancement in removal percentage of LEVO to 92.4% was mainly established by increasing the dose of NBent-NTiO 2 -Chit to 60.0 mg. The extraction mechanisms of LEVO and CFT were positively explained by three models of adsorption isotherm including Langmuir, Freundlich and Temkin. The obtained correlation coefficients (R2) by Langmuir model were 0.952 and 0.987 for LEVO and CFT, respectively to offer excellent fit to the adsorption processes. The thermodynamics parameters of NBent-NTiO 2 -Chit were evaluated and referred that the reaction is spontaneous and endothermic. The kinetic studies of NBent-NTiO 2 -Chit with LEVO and CFT antibiotics were better fitted by the pseudo -second-order based on the acquired R2 values as 0.999 and 0.997 for LEVO and CFT, respectively. The results proved that the designed NBent-NTiO 2 -Chit was successively implemented for extraction of LEVO and CFT from industrial wastewater providing percentage values 83.2 and 79.0% using 10.0 and 150.0 ± 1.0 mg NBent-NTiO 2 -Chit, respectively. Possible bindings of (a) LEVO and (b) CFT onto NBent-NTiO 2 -Chit. Image 1 • Assembly of a novel NBent-NTiO 2 -Chit nanocomposite. • Removal of two Levofloxacin (LEVO) and Ceftriaxone (CFT) antibiotics. • Study and optimization of the equilibrium and removal factors. • Evaluations of the isotherm and kinetics models and thermodynamic parameters. • Successful removal of the two antibiotics from water matrices. [ABSTRACT FROM AUTHOR]
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- 2020
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347. A novel nanobiosorbent of functionalized graphene quantum dots from rice husk with barium hydroxide for microwave enhanced removal of lead (II) and lanthanum (III).
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Mahmoud, Mohamed E., Fekry, Nesma A., and Abdelfattah, Amir M.
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RICE hulls , *QUANTUM dots , *LANTHANUM , *LEAD removal (Sewage purification) , *BARIUM , *ADSORPTION isotherms , *LEAD - Abstract
• Graphene Quantum Dots-Barium hydroxide has been synthesized. • Ultrafast removal of Pb(II) and la(III) by microwave irradiation technique. • Maximum removal of Pb(II) and La(III) at 15 s. • Adsorption isotherms, kinetics and thermodynamic parameters were investigated. • Excellent removal of Pb(II) and La(III) ions from wastewater and tap water. In this study, rice husk was used as a sustainable source to synthesize graphene quantum dots (GQDOs) with 2D morphology. Chemical modification of GQDOs with Ba(OH) 2 was followed to form a novel GQDOs-Ba nanobiosorbent with an increased number of surface hydroxyl groups. The physicochemical properties of GQDOs and GQDOs-Ba were investigated by FT-IR, SEM, TEM, TGA, and XRD. The adsorption parameters of Pb(II) and La(III) onto GQDOs-Ba were optimized using microwave sorption approach. The maximum capacity reached 3400 µmol g−1 (pH 7), and 1500 µmol g−1 (pH 5) at 15 s for Pb(II) and La(III), respectively. The adsorption isotherm models by GQDOs-Ba fitted well with Langmuir. The pseudo -second order was agreed by Pb(II) and La(III) ions. The thermodynamic studies elucidated that Pb(II) and La(III) adsorption onto GQDOs-Ba followed a spontaneous model. The GQDOs-Ba nanobiosorbent accomplished excellent removal percentages from different water samples containing lead (98.5%–99.8%) and lanthanum (94.6%–96.2%). [ABSTRACT FROM AUTHOR]
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- 2020
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348. Catalytic reduction of nitrophenols by a novel assembled nanocatalyst based on zerovalent copper-nanopolyaniline-nanozirconium silicate.
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Mahmoud, Mohamed E., Amira, Mohamed F., Abouelanwar, Magda E., and Seleim, Seleim M.
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CATALYTIC reduction , *SILICATES , *REDUCING agents , *THERMAL stability , *ZERO-valent iron , *NITROPHENOLS , *LEAD analysis - Abstract
A novel nanocatalyst (Cu0-NPANI-ZrSiO 4) was fabricated via solvent free microwave synthesis for surface immobilization of zerovalent copper nanoparticles (Cu0-NPs) on modified nanopolyaniline (NPANI) with nanozirconium silicate. The assembled nanocatalyst was characterized by different techniques to confirm the structure, thermal stability, surface morophology and nanoscale size. Cu0-NPANI-ZrSiO 4 nanocatalyst was then subjected to extensive investigation and evaluation of its potential capability for reduction of a series of nitrophenol (NPhs) derivatives. The Langmuir-Hinshelwood mechanism was applied on the catalytic reduction of 2-nitrophenol (2NP), 3-nitrophenol (3NP) as well as 4-nitrophenol (4NP) and the reaction rate constants (k) were calculated through the pseudo -first-order kinetics due to the presence of excessive NaBH 4. The results revealed a pseudo -first-rate type of reaction with high constant (k). The reduction of NPhs by NaBH 4 as a reducing agent over Cu0-NPANI-ZrSiO 4 was explored in different pH values (2–10) of NPhs and the results confirmed the strong dependency of the reduction process on the pH. In low pH, high reduction efficiency was established and confirmed from the pseudo -first-rate constant k (min−1) for 4NP, 3NP and 2NP as 0.811, 0.249 and 0.584, respectively at pH 2 and these values were then finally decreased to 0.112, 0.1 and 0.116 at pH 10, respectively. Rate constant (k) was in a good correlation with concentration of [H 3 O+] ion. An extrathermodynamic study for reaction rate (k) through isokinetic relationship was mathematically expressed. The calculated thermodynamic parameters led to an extrathermodynamic analysis as a type of compensation effect to give a good linearity plot with the slope to represent the isokinetic temperature, β that was identified as 298.82 at 298 K. Schematic digram for the reduction of NPhs derivatives by Cu0-NPANI-ZrSiO 4 nanocatalyst. Unlabelled Image • A novel nanocatalyst (Cu0-NPANI-ZrSiO 4) was assembled and characterized. • Catalytic reduction of 2-nitrophenol, 3-nitrophenol and 4-nitrophenol. • Strong dependency of the reduction process on the pH. • An extrathermodynamic study for reaction rate (k) by isokinetic relationship. • An extrathermodynamic analysis as compensation effect for linearity. [ABSTRACT FROM AUTHOR]
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- 2020
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349. Amino-decorated magnetic metal-organic framework as a potential novel platform for selective removal of chromium (Vl), cadmium (II) and lead (II).
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Mahmoud, Mohamed E., Amira, Mohamed F., Seleim, Seleim M., and Mohamed, Asmaa K.
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HEXAVALENT chromium , *LANGMUIR isotherms , *METAL-organic frameworks , *CHROMIUM , *CHEMICAL processes , *ADSORPTION isotherms - Abstract
The proposed structure of nFe 3 O 4 @MIL-88A(Fe)/APTMS. • Assembly of novel MOFs meso-porous nFe 3 O 4 @MIL-88A(Fe)/APTMS nanocomposite. • Excellent selectivity for Cd(II), Pb(II) and Cr(VI) ions by nFe 3 O 4 @MIL-88A(Fe)/APTMS. • Removal of Cd/Pb cations were accomplished by coordinate bond formation at pH > 4. • Removal of Cr(VI) in the anionic form was confirmed via ion-pair attraction at pH < 4. • Adsorption evaluation by six kinetics models and six adsorption isotherms. In this work, the –NH 2 functional group via 3-aminopropyltrimethoxysilane (APTMS) was selected to anchor onto the pore surface of magnetic metal organic framework using microwave green chemical process. The prepared nanocomposite was investigated for potential and fast removal of cationic Cd(II), Pb(II) as well as anionic Cr(VI) species via batch adsorption. Six kinetics models were applied in order to examine the adsorption mechanisms; the obtained data confirmed that the investigated metal ions followed the pseudo -second order model. The adsorption processes were fitted to the Langmuir model and the maximum adsorption capacities of cadmium (II), lead (II) and chromium (VI) ions were 693.0, 536.22 and 1092.22 mg g−1. In addition, thermodynamic study confirmed the endothermic and spontaneous adsorption reactions. The nFe 3 O 4 @MIL-88A(Fe)/APTMS was easily regenerated and the adsorptive removal values were decreased by only 3% after five consecutive recycling processes. The recovery values from tap water, sea water and wastewater were identified as Cd(II) (98.49, 96.22 and 94.73), Pb(II) (96.88, 93.31 and 91.81) and Cr(VI) (99.69, 98.01 and 95.46), respectively. [ABSTRACT FROM AUTHOR]
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- 2020
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350. Functionalization of CeO2-SiO2-(CH2)3-Cl nanoparticles with sodium alginate for enhanced and effective CdII, PbII, and ZnIIions removal by microwave irradiation and adsorption technique
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El-Sharkawy, Rehab M., Allam, Elhassan A., and Mahmoud, Mohamed E.
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- 2020
- Full Text
- View/download PDF
Catalog
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