M.E. Ossman

Decolorization of industrial wastewater by ozonation followed by adsorption on activated carbon

The decolorization of industrial wastewater containing direct dye (Drimarene Red CL-3B) by advanced oxidation process using ozonation in a semi-batch bubble column reactor followed by granule activated carbon (GAC) adsorption process was studied. The effect of initial dye concentration, ozone concentration, pH and ozone-air flow rate on the rate of dye decolorization were investigated. It was found that the rate of dye decolorization increases with increasing ozone concentration, ozone-air flow rate, and pH but decreases with increasing initial dye concentration. This study is a hybrid system conducted in combination between ozonation process and GAC adsorption to reveal higher and efficient removal of color and TOC. The process started with ozonation for efficient and rapid decolorization of dyeing wastewater, followed by GAC adsorption process to gain efficient removal of color and TOC. The adsorption process was found to be very efficient in removal of ozonation residual TOC, in view of high TOC removal, up to 37% TOC removal was obtained. Numerical correlation using regression analysis for decolorization time with the operating conditions of the ozonation process were presented.

Removal of Cd(II) ion from wastewater by adsorption onto treated old newspaper: kinetic modeling and isotherm studies

BackgroundThis paper studied the ability of using treated old newspaper (TNP) as synthetic adsorbent for the removal of Cd(II) from aqueous solutions by batch operation. Various operating parameters such as pH, initial metal ion concentration, adsorbent dosage, and equilibrium contact time have been studied.ResultsThe results indicated that the adsorption of Cd(II) increased with the increasing pH, and the optimum solution pH for the adsorption of Cd(II) was found to be 6.4. Adsorption was rapid and occurred within 15 min for Cd(II) concentration range from 5 to 30 mg/L.ConclusionsThe kinetic process of Cd(II) adsorption onto TNP was found to fit the pseudo-second-order model. The equilibrium adsorption data for Cd(II) were better fitted to the Langmuir adsorption isotherm model.

Fe (III) removal by activated carbon produced from Egyptian rice straw by chemical activation

AbstractThe present work explored the use of Egyptian rice straw, an agricultural waste that leads to global warming problem through brown cloud, as a potential feedstock for the preparation of activated carbon. Chemical activation of this precursor using two different methods was adopted. The produced activated carbon was fully characterized considering its adsorption properties, as well as its chemical structure and morphology. Application of using the produced activated carbon and raw rice straw for removal of the Fe(III) was evaluated in a batch operation system. The results indicated that the rate of uptake of the Fe(III) is rapid in the beginning and 80% adsorption is completed within 50 min, and the time required for equilibrium adsorption is 60 min. The removal efficiency of Fe(III) depends on the pH of the solution. The optimal Fe(III) removal efficiency occurs at pH 5. The adsorption isotherm analysis showed that the Freundlish isotherm provides a good model for the sorption system. The 1/n is l...

Kinetic modeling and isotherm study for naphthalene adsorption on boehmite nanopowder

Abstract Boehmite was synthesized and characterized in order to study the adsorption behavior and possibility to remove naphthalene as one of the polycyclic aromatic hydrocarbons (PAHs) from industrial waste water. The removal of naphthalene was investigated in terms of various parameters namely: pH, operating time, initial concentration of naphthalene and weight of adsorbent using batch technique. The data showed that the adsorption of naphthalene onto boehmite is not affected by changes in the pH. Adsorption data of naphthalene on the boehmite nanopowder were analyzed according to Freundlich, Langmuir adsorption and Redlich–Peterson models. The data were found to be best described by the Freundlich model. The kinetics of the adsorption was found to be fitted with a pseudo second order model. The negative values for free energy indicated that the spontaneous nature of the adsorption with a high performance of naphthalene for boehmite and also negative values of the enthalpies indicated that the process i...

Modeling of fluidized bed reactor for ethylene polymerization: effect of parameters on the single-pass ethylene conversion

BackgroundIn this study, we present the developments in modeling gas-phase catalyzed olefin polymerization fluidized bed reactors (FBR) using chromium catalyst technique. The model is based on the two-phase theory of gas-solid fluidization: bubble phase and emulsion phase. The model has proved to be the suitable model in many of past studies. In the proposed model, the bed is divided into several sequential sections. The effect of important reactor parameters such as superficial gas velocity, catalyst injection rate, catalyst particle growth, and minimum fluidization velocity on the dynamic behavior of the FBR has been discussed. The conversion of product in a fluidized bed reactor is investigated and compared with the actual data from the plant site.ResultsA good agreement has been observed between the model predictions and the actual plant data. It has been shown that about 0.28% difference between the calculated and actual conversions has been achieved.ConclusionsThe study showed that the computational model was capable of predicting the hydrodynamic behavior of gas-solid fluidized bed flows with reasonable accuracy.

Physical characterization and microstructure evaluation of graphite carbon nitride-CuO photocatalytic composite and its application in organic pollutants degradation

N including quantum dots, fullerenes, nanoparticles (zero dimension), nanotubes, nanowires, nanofibrils (one dimension), and graphene (two dimension) possess intriguing physical, chemical and biological properties. As a consequence, these materials form the basis of many interdisciplinary studies, where scientists have been inspired by self-assembly processes occurring in nature to construct advanced nanomaterials with applications in many fields. Self-assembly involves the organization of molecules into highly ordered structures through specific, local interactions among the components, without any external direction. Weak interactions, such as Van der Waals, electrostatic, and π-π interactions, as well as hydrogen bonding, and halogen bonding can lead to all kinds of challenging self-assembled nanostructures. The hierarchical structures of many peptides are attributed to self-assembly, therefore, could potentially act as building blocks for new materials with significant functionalities and a range of biological functions. In our recent work, non-covalent interactions including hydrogen bonding, hydrophobic interaction and electrostatic interaction were employed to modulate the peptide assembled nanostructures. We could successfully realize the peptide assembly transition from nanospheres to nanofiber by tuning hydrogen bond and hydrophobic interaction; furthermore, two dimension peptide nanopatch could be constructed instead of nanofiber by introducing the terminus intermolecular hydrogen bonding between the peptide and small molecules. The electrostatic interaction was proved to play an important role in peptide self-assembly and disassembly. Furthermore, it is significant to be addressed that the mechanical properties of peptide assemblies do changing after the nanostructure transition of peptide occurred. These peptide-based nanostructures could potentially be applied to be a candidate of biomaterials with potential importance in a wide range of technological applications.Z oxide (ZnO) nanoparticles (grown in the template of folic acid) are biologically useful, luminescent material. It can be used for multifunctional purposes, such as biosensor, bioimaging, targeted drug delivery and as growth promoting medicine. Though, ZnO is categorized as: “generally recognized as safe” (GRAS) but ZnO nanoparticle system may be cytotoxic. ZnO nanosystem could be of important relevance in the context of nanomedicine, where targeted treatment of biological systems at molecular level is a necessity. ZnO quantum dots with their surface modification and bio-conjugation for selective destruction of tumor cells and their potential use for drug delivery applications is the cardinal issue of this presentation..Nano-sized particle incorporation into metal matrix for fabrication of advance surface coatings find variety of applications in surface protection techniques. Al 2 O 3 , Cr 2 O 3 and SiO 2 nanoparticles have been codeposited with Zn using electrodeposition process to produce Zn nanocomposite coatings. The fabricated coatings were characterized using Scanning Electron Microscope affixed with Energy Dispersive Spectroscopy and X-ray diffractometer. The mechanical and tribological properties of the coatings were investigated using diamond microhardness indenter and dry abrasive wear tester. Zn-10g/L Cr 2 O 3 nanocomposite exhibited the highest microhardness of 228 HV and Zn-5g/L Al 2 O 3 nanocomposite possessed the highest corrosion resistance and lowest wear loss. Zn-5g/L SiO 2 nanocomposite showed good stability as compared to other composite coatings. The incorporation of the nanoparticles of Al 2 O 3 , Cr 2 O 3 and SiO 2 induce grain refinement and modify crystallographic orientation of Zn matrix. Zn-5g/L Al 2 O 3 and Zn-5g/L SiO 2 proved to be better coatings which can find variety of industrial applications where both mechanical and electrochemical properties are required.The existence of vibrations in undesired parts of mechanical machinery, civil structures, aerospace and automotive components,will cause overall setback and efficiency reductions in processes when the above parts are used. Hence is advising to completely get rid of the unnecessary vibrations or reduce them to a minimum possible value. This experiment is an effort to reduce these vibrations using Magneto Rheological fluids. A Magneto Rheological fluid provides viscous damping. The damping factor increases when a magnetic field is applied and is multiplied as the strength of the magnetic field is more, also the natural frequency of the body under test changes from to a value which is different from the initial value. This technique was utilized and a three layered MR fluid sandwich beam was fabricated. This beam was subjected to testing and analysis under both undamped and damped conditions. The controllability of variations in the various dynamic parameters like natural frequencies, vibration amplitudes and damping factors were observed. A reduction is natural frequency of beam was obtained in the presence of MR fluid under magnetic field, from 550 Hz to 300 Hz. Keywords: Magnetorheological fluid, MRFluid sandwich Beam, Natural frequency, Damping factor, Damping coefficient.A perovskite-like phase, K3B6O10Cl exhibits a large second harmonic response about four times that of KH2PO4 (KDP) and is transparent from the deep UV (180 nm) to middle-IR region. A high quality single crystal of K3B6O10Cl with dimensions up to 30 × 15 × 7 mm3 was successfully grown by the top-seeded solution growth method. Crystal morphologies and growth habits of K3B6O10Cl grown with seeds oriented along [101] and [211] were studied, and the best growth direction was obtained., The refractive indices of the crystal were measured by the minimum deviation technique and fitted to the Sellmeier equations. The nonlinear optical coefficients have been determined by the method of Maker fringes at λ=1064 nm. The suitable nonlinear optical coefficients as well as comparatively easy crystal growth make the K3B6O10Cl crystal a promising candidate for NLO materials.A carbon and fiberglass are the two mostly studied materials in air filtration industry due to their good performance with associated low cost. The advancement in the field of nanoscience and nanotechnology produced materials with improved properties than conventional materials. Nanofibers are one of the nanotechnology products, which have been explored for applications such as healthcare, water, energy, electronics, catalysis, environmental, air filtration, bioengineering and biotechnology. Pores and pore size distribution of nanofibers can be easily tunable. Recently, they have been explored in various air filtration products such as high efficiency particulate absorption (HEPA) filters and so on. In this talk, various nanofibers that are electrospun and deposited on HEPA filters, process variation, additives addition, and their performances, challenges faced and their potential application in air filtration industry will be presented.O (OA) and meniscus injury are often met from injury and aging. In the USA alone, approximately 50 million people are affected by OA, and over 50% among them require replacing total joints, which cost approximately

Removal of Cd (II) ion from waste water by adsorption onto polyaniline coated on sawdust

15 billion per year. Tissue engineering (TE) approach to cartilage regeneration has promises to repair damaged or diseased cartilage. Biodegradable scaffolds as one of key elements in TE are expected to offer a complex biological microenvironment mimicking with native tissue to promote cell ingrowth and tissue regeneration. However, current scaffolds cannot simulate the complex microenvironment of native cartilage. To the end, our group developed a biodegradable extracellular matrix (ECM) hydrogel derived from pig cartilages. The hydrogel contained complex components including collagen, glycosaminoglycan, growth factors and peptides, which were mimetic with biological components in the cartilage. This hydrogel solution was flowable at 4oC and formed a solid hydrogel at a body temperature, which is appropriate for non-invasive surgery. The mechanical properties of the hydrogels could be tuned by altering ECM concentration. The chondrocytes survived and proliferated inside the hydrogel with a round shape due to a good cellular microenvironment. The hydrogel solution was easily injected into a mouse subcutaneous model and formed a solidified hydrogel in vivo. No severe immunogenetic response was observed till to 7 day implantation, indicating a good biocompatibility. The attractive injectability and biomimetic complexity showed that the cartilage-derived hydrogel would be a good candidate to be applied for cartilage regeneration.T development of silver nanoparticle (AgNPs) as a potent alternative to conventional antibiotics has been extensively investigated over the last decades. However, due to the prominent cytotoxic effect of silver on mammalian cells, there is always strong motivation to develop alternative technology that can compact bacterial infection without affecting the mammalian cells. Capping AgNPs with appropriate functional groups and incorporating them into a polymeric matrix is a feasible alternative to overcome these limitations. AgNPs with different chemical structures (nanocapsules and nanoparticles) and functionalities (polymer, lipid, and starch) were synthesized. To demonstrate application as antibacterial coatings, the stabilized AgNPs were then immobilized onto model surfaces made of a thin layer of allylamine plasma polymerized film. This substrate-independent technique preserves the AgNPs functionalities for a longer period of application time. All fabricated surface coatings exhibited superior antibacterial activity against four important Gram-positive and Gram-negative pathogens. This study further aimed to focus on investigating the effects of AgNPs surface components on delivery of engineered AgNPs from the coatings into the human fibroblast cell as well as bone marrow derived macrophages (BMDM). Most of the surfaces did not affect BMDM function or viability and demonstrated no toxicity toward fibroblast cells, except for lipid coated nanosilvers. Therefore, the chemical structures of nanoparticles significantly affect the coatings’ antibacterial, biofilm prevention and biocompatibility capabilities. We believe that such biocompatible nanostructures are of potential interest for various biomedical applications such as smart drug carriers and antibacterial coatings for medical devices and wound dressings.I order to develop compliant seal systems for SOFCs operating in the temperature range of 800-950°C, this project has focused on iterations in materials systems. The materials consisting of composites of a base glass with appropriate ceramic components in order to identify a stable sealing system with adequate and acceptable thermal characteristics, such as, the viscosity and coefficient of thermal expansion. Appropriate viscosity was targeted to ensure good flow behavior of the glass at temperatures where fuel cells operate and sealing effects are required. Viscosity variation in the composites was brought about by the selection of ceramic additives; a large number of candidates ranging from phase pure alumina, magnesia, ceria and barium zirconate, to ceria doped with 10 mole % gadolinium oxide (GDC). SCN1 glass (trade name of sealing glass developed by SEM-COM) was used as the base component, whose composition was such as to provide a CTE match with the SOFC system (in the RT-Tg range), when composited with a second ceramic phase. Additives in both nanoand micro-scale dimensions (as fine powders or in the form of fibers) were introduced mainly to block the bubbles from moving but also to make the composite structure stronger. In addition, their role was also to inhibit the growth of air bubbles within the glass matrix and to or prevent their coalescence during long soak-time at 850°C, with the goal of eliminating or minimizing the CTE drift in the resultant glass composition. No reaction between SCN1 glass and the GDC additives was discerned. Moreover, the bubbles remained small and did not move or coalesce. The CTE of the GDC composites was very close to the targeted value and not change significantly when aged up to 232 h at 850°C in air.