Sharif Digital Repository

Organic dye couldn’t be treated by conventional method (biological method) due to their durable structure. In recent years, graphene based adsorbent has become more popular; this is because of high specific surface area and presence of numerous functional group on its surface. Due to the widespread application of organic dye in different industry especially in textile industry, stability and toxicity nature of them, finding an appropriate and cost effective method in treatment of this pollutant is very important. In this study, preparing and characterization of 3-D gel magnetic graphene oxide/kappa carrageenan was conducted and its ability of dye adsorption was tested. For this purpose, at... 

During the recent years, shortage of drinking water is one of the concerns of the society and necessity of purification of contaminated water are taken into consideration. Different methods to be developed to prevent problematic pollutions. Among these different methods the most common one is adsorption. In this thesis, the copper oxide nanoparticle was synthesized and its surface was modified using N-(2-aminoethyl)-3-(trimethoxysilyl)propylamine. The bi-amino surface functionalized nanoparticle was used to remove anionic dyes from single and binary systems. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDAX)... 

Hyderogels are hydrophilic polymers with three dimensional network structure, due to their high water absoption, their application to life and industry is increasing from day to day, such as tissue engineering, actuators and sensors, drug delivery and therapeutic treatment. In this project, it has been attempted to produce polyacrylamide/alginate double network hydrogels with the use of graphene oxide nanosheets to indicate that it is possible to combine toughness and self-healing in a hydrogel with the opposite nature of each other. To evaluate mechanical properties, uniaxial tensile test and loading-unloading test were used. The results indicate that increase the weight ratio of acrylamide... 

Based on the new standards, less than 10 ppm sulfur is allowed for the automotive fuels. This has led researchers to try improving the present conventional methods as well as seeking alternative routes for refinement of the petroleum products so much to comply with the requirements. Since thiophenic fragments such as dibenzothiophene (DBT) are the most durable sulfur compounds in the current hydrodisulfurization method, many studies have been conducted over recent years on how to remove these compounds. In this thesis, the desulfurization of dibenzothiophene from gasoline via adsorption method was studied. In order to carry out the adsorption process, a nanocomposite of graphitic-carbon... 

Due to the technology advancement and the large-scale application of lithium-ion batteries in recent years, the market demand for lithium is growing rapidly and the availability of land lithium resources is decreasing significantly. As such, the focus of lithium extraction technologies has shifted to water lithium resources. Among various aqueous recovery technologies, the lithium ion-sieve (LIS) technology is considered the most promising one. This is because LISs are excellent adsorbents with high lithium uptake capacity, superior lithium selectivity, and good cycle performance. TiO2-based nanotubes are an appropriate option for adsorbing lithium from solution due to their high specific... 

In this work, CO interaction with macroscopic Ni(111) surface and microscopic Nin (n = 2-4) clusters were investigated. First, the CO interaction with various adsorption sites were studied by DFT methods on Ni(111) surface. On the basis of these calculations, hcp site has the strongest interaction with CO adsorbate. Then, the vibrational frequencies of C=O and adsorptive bond on the hcp site were calculated and the results show that anharmonicity of adsorptive bond is more important than C=O bond. Therefore, three potential models are considered for adsorptive bond and the effect of potential models on its thermodynamic properties was investigated. The results show that the effect of... 

In this project, using experimental results for permeation of gases H2, He, N2, and CO on a microporous membrane (the applied sample was a ceramic membrane) and modified equations, pore diameter, tortuosity, and porosity were determined for this type of membrane. Furthermore, pore diameter, critical volume, and characteristic energy of a carbon molecular sieve membrane were calculated using experimental data for CO2 adsorption on this type of membrane. Diffusivities of CO2, N2, and Ar were also calculated by means of the uptake, time lag/adsorption, and permeability/adsorption tests on carbon molecular sieve membranes utilizing experimental data obtained for this type of membranes and the... 

In the present study, simultaneous adsorption of water, mercaptans, carbon dioxide and heavy hydrocarbons on three layers bed, namely Activated Alumina, 4A and 13X Molecular Sieve, on PTSA process is designed and simulated for LNG production. The level of water and mercaptan should be decreased to less than 0.1 ppmv at the bottom of zeolite 4A and 3 ppmv at the bottom of zeolite 13X layer respectively. The main purpose of this study is to investigate the dynamic simulation of multi-component adsorption on a multi-layer bed and to predict the effect of different operational variables on adsorption performance. Multi-layer bed decreases the investment cost and operational challenges in... 

In this project, theoretical and experimental study of methane adsorption on Multiwall Carbon Nano-Tubes (MWCNT) has been performed. This study has been conducted in the way to achieve a suitable method for methane storage and transportation. To carry out the experiments, the volumetric method was used up to 500 psia at various temperatures of 298.15 K, 303.15 K, 308.15 K. The effect of moisture was also studied at 298.15 K. Also, various adsorption isotherms were used to model the experimental data collected in this work. The results showed that the amount of methane adsorbed on the MWCNT can decrease with increasing the moisture and temperature of the adsorption cell. In order to... 

Phenolic compounds are important environmental pollutants that the removal and separation of them from the water and industrial wastewater especially in the oil industry is essential before entering the environment. In the present study, the removal efficiency of the adsorbent silica aerogel 4-Chlorophenol and 4-Bromophenol as phenolic compounds from aqueous solution was surveyed. In this research, the effects of various factors such as contact time, pH, and initial concentration of the pollutant and the adsorbent on the adsorption were studied. It was observed that there is a large amount of adsorption in acidic pH and this amount increases by incrementing the concentration of the... 

gas adsorption in porous solids and adsorbent,is the important cases in gas processing industries. Including the removal of compounds such as carbon dioxide, hydrogen sulfide and mercaptans from sour gas in natural gas sweetening industry is of great importance.Also in solving the greenhouse phenomena extraction of gases such as methane and carbon dioxide of important environmental issues.To understand and predict the behavior of the absorption capacity of various adsorbents and thus the possibility of absorption systems, a mathematical model is needed.Library resources available in order to determine the kinetics and thermodynamic processes of gas adsorption on solid absorbents use... 

In the present thesis, the adsorption ability of the functionalized magnetic nano-particles supported on the walnut and almond based activated carbons was evaluated to prepare the efficient and low cost adsorbents for removal of Pb(II), Cr(VI) and Hg(II) ions aqueous solutions in the presence of salinity. The activated carbons were derived from almond and walnut shell by the physical activation method. The functionalized nano-magnetic activated carbons were synthesized by co-precipitation consisting of AC(almond)@Fe3O4@SiO2-NH2-COOH and AC(walnut)@Fe3O4-NH2-COOH which were modified by the oxygen containing functional groups to enhance the adsorption capacity. The prepared carbonaceous... 

In this project, polymer nanocomposites containing graphene oxide were prepared and used for adsorption of several cationic and anionic dyes. In most cases, these nanocomposites were prepared as three-dimentional polymer networks which contain graphene oxide. Nanocomposites with direct grafting of polymer chains onto the surface of graphene oxide were also prepared. Graphene oxide is an oxidized carbonaceous material with unique properties. This material has high surface area, good mechanical strength and various functional groups. Polymeric compounds with different functional groups, structures and properties can be prepared and used. By preparing composites of graphene oxide and polymers,... 

Heavy metals such as lead, chromium, nickel are considered as environmental pollutants. These substances are highly toxic and dangerous to humans and other organisms at low concentrations and many problems are caused by them. Chromium belongs to the group of heavy and toxic metals. Form 6-valent chromium for humans is considered a definite carcinogen and also creates other problems. One common method of chromium removal is chemical precipitation which caused a large volume of waste. Other methods such as ion exchange, solvent extraction, reverse osmosis and biological methods are used to remove chromium. Adsorption is another effective method with very few disadvantages compared to other... 

Today, with expanding industries, wastewater treatment of them is a global problem. Heavy metal is one of the most common and most dangerous contaminants in waste water that over time, with the strict standards of output, find more effective ways of eliminating them has always been a challenge. New methods, especially in the field of adsorption have achieved promising results in many cases.
Polymers composites are one of the adsorbent for the removal of these contaminants have been considered. In this project Aniline and composites to remove arsenic and chromium were studied. In polymers synthesis factors like type of additives and oxidizing materials strongly effected on morphology of... 

Apatite-coated Ag/AgBr/TiO2 was prepared by deposition of Ag as noble metal to generate electron-hole pairs by extending the excitation wavelength to visible light region, AgBr as photo-sensitizer to increasing yield of photo catalyst, and apatite as adsorption bio ceramic for adsorbing pollutants and micro organisms respectively. The bactericidal experiments in dark media indicated that only novel catalyst show inhibiting growth of bacteria. In this case Transmission electron microscopy image illustrated that catalyst nano particles adhere to the outer membrane of the cell and acts as inhibitor to nourish of bacteria from around media. The mechanism for deactivation E-Coli and B.Sub in the... 

Porous polymeric particles have the extensive application in various sciences and various methods have been introduced for production of these particles. Depending on method of production, porous polymeric beads can be produced in diverse shapes, pore size, pores interconectivity, surface morphology and chemical properties. In common methods for production of porous polymeric particles, tuning the size and porosity is difficult or even impossible. Porous polymeric beads with the vast surface area and good functionality have been applied for adsorption of various materials. The purpose of this study is therefore to investigate a new procedure for the production of porous polymeric... 

In this project, the feasibility of hydrocarbon waste water treatment with low concentration by physical- chemical treatment methods will be discussed. The purpose of this thesis is to investigate the feasibility of reusing the water outlet of the oil and gas refineries, in the region of ASALUYEH where there is an urgent need for water. By using activated carbon and wooden absorbent (absorption method) efficiency of this method was determined. Both coagulation and flocculation methods were investigated. To design and optimize various operating conditions on the adsorption process the RSM method was used. Temperature, residence time, feed concentration, amount of adsorbent, and adsorbent ... 

One of the common methods used for treatment of gaseous radioactive wastes in nuclear waste management is adsorption process. Nanoporous materials have found great utility as sorption media because of their large internal surface area and more adsorption sites than other adsorbents, which caused the increasing attention of researchers to use them in the nuclear waste management. Hence in this study, the surface of nanoporous silicates of SBA-15 and MCM-41 modified with d-block elements of the periodic table such as silver, copper, zinc and nickel by wet impregnation method. After characterization by different techniques such as X-ray diffraction, nitrogen gas porosimetry, Fourier... 

To investigate the metallic cation (Ni and Pb) removal performance of the rice barn-obtained biochar which was modified by nitric acid and titanium nanoparticles (TiO2) adsorption tests were conducted in continuous and non-continuous systems. First section addressed the characterization of the synthesized sorbents using field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy dispersive X ray spectroscopy (EDX) and sorption-desorption porosity analysis (BET). In the second section, the effect of different parameters such as pH, initial concentration of the metallic ions, temperature, time, sorbent content, ionic...