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    Rapid start-up and improvement of granulation in SBR

    , Article Journal of Environmental Health Science and Engineering ; Volume 13, Issue 1 , 2015 ; 2052336X (ISSN) Jalali, S ; Shayegan, J ; Rezasoltani, S ; Sharif University of Technology
    BioMed Central Ltd  2015
    Abstract Background: The aim of this study is to accelerate and improve aerobic granulation within a Sequencing Batch Reactor (SBR) by cationic polymer addition. Methods: To identify whether the polymer additive is capable of enhancing granule formation, two SBRs (R1 and R2, each 0.15 m in diameter and 2 m in height) are used by feeding synthetic wastewater. The cationic polymer with concentration of 30 to 2 ppm is added to R2, while no cationic polymer is added to R1. Results: Results show that the cationic polymer addition causes faster granule formation and consequently shorter reactor start-up period. The polymer-amended reactor contains higher concentration of biomass with better... 

    Experimental studies on the effects of process parameters on granule properties in a conical high shear granulator

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 32, Issue 3 , 2013 , Pages 115-125 ; 10219986 (ISSN) Ranjbarian, S ; Farhadi, F ; Sharif University of Technology
    Jihad Danishgahi  2013
    Experimental work was carried out to investigate the influence of impeller speed, granulation time, binder mass and their interactions on granule size distribution, mean size and binder content distribution in a conical high shear granulator. It was observed that the response of high shear granulation to changes in process parameters varies significantly from one operating condition to another. For all quantities of binder, the granule mean size increased with time at lower impeller speeds, while the opposite trend was observed at higher impeller velocities. For long mixing times, increasing impeller speed decreased the granule average size constantly; whereas for other durations, an... 

    Evaluation of the effects of process parameters on granule mean size in a conical high shear granulator using response surface methodology

    , Article Powder Technology ; Volume 237 , 2013 , Pages 186-190 ; 00325910 (ISSN) Ranjbarian, S ; Farhadi, F ; Sharif University of Technology
    Response surface methodology was used to investigate the effects of operating parameters such as impeller speed, binder mass and granulation time on the average size of granules produced in a lab scale conical high shear granulator. Two quadratic models were proposed to express granule mean size as a function of impeller speed and binder mass as well as impeller speed and granulation time. It was found out that in the studied domain, the influence of each parameter on granule size differs from one another. While increasing binder mass at constant quantity of powder increased the average size linearly, increasing impeller speed changed the mean size in accordance with quadratic trend. The... 

    Evaluation of Granularity of Reconfigurable Architectures for Wireless Communication Applications

    , M.Sc. Thesis Sharif University of Technology Nazarieh, Masoumeh (Author) ; Hemmat yar, Afshin (Supervisor)
    Wireless communication applications need high computing power, flexibility and scalability. Although ASICs have the ability of high computing power but they are not flexible to changing or completing of communication protocols. On the other hand, general purpose microprocessors or DSPs are flexible, but do not provide sufficient computing power. Thus devices with reconfigurable architecture have been proposed as a compromise between ASICs and microperocessors. One of the main features of reconfigurable devices is the granularity. The granularity of a reconfigurable devices shows the amount of computing power incorporate in a processing element. In this thesis we have evaluated different... 

    Granulated copper oxide nano-catalyst: A novel and efficient catalyst for C-N cross-coupling of amines with iodobenzene

    , Article Monatshefte fur Chemie ; Volume 142, Issue 8 , 2011 , Pages 801-806 ; 00269247 (ISSN) Ahmadi, S. J ; Sadjadi, S ; Hosseinpour, M ; Abdollahi, M ; Sharif University of Technology
    Nano-structured CuO granules catalyze the C-N cross-coupling of amines with iodobenzene in excellent yields. The reaction is simple, efficient, and operates in air under ligand-free conditions  

    Phenomenological Study of Granulation by Investigating the Effects of Operating Parameters on Granule Properties

    , Ph.D. Dissertation Sharif University of Technology Ranjbarian, Sima (Author) ; Farhadi, Fathollah (Supervisor)
    The present thesis has provided more fundamental understanding of granulation rate processes (such as coalescence, attrition and breakage) by investigating the effects of operating parameters on product properties. The studied process was wet granulation carried out in two high shear mixer granulators. Granulation duration, binder mass and impeller speed were considered as operating parameters and granule size distribution (measured by sieving) and granule binder distribution (measured by thermogravimetery method) were regarded as product properties. Experiments were conducted in two analogous cylindrical and conical high shear granulators. The obtained experimental and theoretical results... 

    Discretized n-dimensional population balance for agglomeration

    , Article Industrial and Engineering Chemistry Research ; Volume 52, Issue 49 , December , 2013 , Pages 17487-17500 ; 08885885 (ISSN) Hashemi Amrei, S. M. H ; Molaei Dehkordi, A ; Sharif University of Technology
    In this article, a new method for solving multidimensional population balance (PB) equations for agglomeration is presented. First, discretized 2-dimensional PB (DPB) is derived and by applying probability approach, this method is extended to n-dimensional PB. The discretization of size intervals is in the form of v(j) = 2j-i v(i) and the volume based PB is used. Because of conservative nature of volume, all internal coordinates are converted to some independent volumes. A simple and clear procedure for solving multidimensional PB is proposed using probability concept. In addition, various types of birth and death mechanisms involved in PB are analyzed separately. Moreover, results of... 

    Effect of pH on aerobic granulation and treatment performance in sequencing batch reactors

    , Article Chemical Engineering and Technology ; Volume 38, Issue 5 , 2015 , Pages 851-858 ; 09307516 (ISSN) Rezasoltani, S ; Shayegan, J ; Jalali, S ; Sharif University of Technology
    Wiley-VCH Verlag  2015
    Two sequencing batch reactors were operated to investigate the effect of influent alkalinity and reactor pH on aerobic granulation. In the first reactor R1 with high influent alkalinity the pH was adjusted in the neutral range, and in the second reactor R2 with low alkalinity the pH was held within the acidic range. The R1-dominating species were bacteria and the appearance time of granules was three weeks after reactor start-up. On the other hand, the acidic environment of R2 provided favorable conditions for fungal growth, and rapid granule formation occurred within the first week of operation. The varying microbial structure of granules resulted in different reactor performance in terms... 

    Feasibility Study of Manufacturing of Disposable Plant Containers

    , M.Sc. Thesis Sharif University of Technology Hosseini Vala, Hamid (Author) ; Mostafavi, Mostafa (Supervisor)
    The aim of the present research is to analyse feasibility study of manufacturing the disposable (Biodegradable) plant containers in Iran. The population of the research consists of the whole capacity for manufacturing this product and the similar product producers which have been registered in the Ministry of Industry, Mines and Commerce. First, in this research, the environmental and anti-environmental impacts of non-plant Disposable Containers like: plastic, foam, paper and aluminum have been discussed and also their disadvantages have been examined to be compared with advantages of using plant Disposable Containers. Thereafter, collecting the required data about today society and market,... 

    Modeling of Spray Granulation

    , M.Sc. Thesis Sharif University of Technology Hashemi Amrei, Mohammad Hossein (Author) ; Molaei Dehkordi, Asghar (Supervisor)
    Fluidized bed spray granulation is an important powder production process with several key advantages compared to other powder production processes, such as spray drying. Moreover, in fluidized bed granulators, whole process takes place in just one apparatus and there is no need to side processing. Most important characteristics and essential part of fluidized bed granulation is the wetting of primary particles by atomized liquid binder to coating the primary particles and producing granules. To date, a lot of research has focused on modeling and understanding of the separate particle growth mechanisms which have been integrated into the population balance models. Although, these concepts... 

    Design and Construction of Aerobic Granulation Reactor in Order to Study the Effect of Cationic Polymer on Granular Formation

    , M.Sc. Thesis Sharif University of Technology Jalali Varnamkhasti, Sajjad (Author) ; Shaygan Salek, Jalaloddin (Supervisor)
    Despite many advantages of granular sludge in anaerobic reactors (e.g. UASB), over the past few years research attention had turned towards developing aerobic granular sludge. Although much research is carried out on the formation of aerobic granules, less work is reported on how to enhance granules characteristics such as increasing in granule size, concentration, durability and stability. The aims of this study are to investigate the effects of cationic polymer on granule formation and the way to improve granule characteristics. For this purpose two SBR reactors (0.15 m diameter and 1.8 m height, R1 and R2) were used by feeding synthetic wastewater (diluted molasses, COD ranging from 1400... 

    Designing Granular Sequencing Batch Reactor for Investigating the Effect of Influent Feeding Alkalinity and Rreactor pH on Aerobic Granulation

    , M.Sc. Thesis Sharif University of Technology Rezasoltani, Samira (Author) ; Shaygan, Jalal (Supervisor)
    Laboratory experiments were carried out to investigate the effect of influent alkalinity and reactor pH on microbial species, morphology and performance efficiency of aerobic granules. The experiments were conducted in two L sequencing batch reactors (R1-R2) with different influent alkalinity and pH medium. pH in R1 ,with high influent alkalinity, was in the range of 7-7.5 and pH in R2 was adjusted in 4.5-5.5. The experimental results demonstrated that the dominated microbial species and structure of granules were different in two rectors. Acidic environment of R2 provide favorable condition for fungal growth and granules formed within first week of operation. On the other hand in R1,... 

    A theoretical and experimental investigation of wastewater treatment for a polyethylene terephthalate production unit

    , Article Chemical Engineering Transactions ; Vol. 39, issue. Special Issue , 2014 , p. 751-756 ; 22839216 Vafajoo, L ; Mohammadpour, A ; Khorasheh, F ; Sharif University of Technology
    In this research, mathematical modelling of an anaerobic hybrid bioreactor for effluent treatment of a Poly-Ethylene Terephthalate (PET) unit in a petrochemical complex was performed. The developed model included a combination of a biofilm model for describing the substrate kinetics; a fluidized bed model for determination of species profiles along the reactor length and a bioreactor model for particle distribution inside the reactor. The reactions performed in the bioreactor included; i) the polymers hydrolysis; ii) fermentation of the resulting monomers; iii) the volatile fatty acids fermentation to Acetate and Hydrogen and iv) the Methane formation as the final product. The reactor was... 

    Adsorption and diffusion of Xenon in a granulated nano-NaY zeolite

    , Article Adsorption ; Volume 18, Issue 2 , 2012 , Pages 75-86 ; 09295607 (ISSN) Charkhi, A ; Kazemeini, M ; Ahmadi, S. J ; Allahyar, S. A ; Sharif University of Technology
    Springer  2012
    Henry's law constant and crystal diffusivity of xenon in the granulated nano-NaY zeolite were measured by the pulse gas chromatography method. For this purpose the moments of response peaks of xenon were analyzed. The effect of extra column parts of the utilized chromatographic system was also considered by analyzing the moments of the response peak which was obtained by pulse injection of inert gas of helium into the carrier gas of nitrogen. In addition, the measurement of average velocity of the carrier gas regarding the pressure drop in the extra column parts of the system attributed to precise results. By carrying out the experiments at various temperatures in the range of 30-110 °C the... 

    Adsorption behavior of toxic metal Ions on nano-structured CuO granules

    , Article Separation Science and Technology (Philadelphia) ; Volume 47, Issue 7 , 2012 , Pages 1063-1069 ; 01496395 (ISSN) Ahmadi, S. J ; Sadjadi, S ; Hosseinpour, M ; Sharif University of Technology
    In this study, copper oxide nano particles were synthesized by batchwise supercritical hydrothermal method. After preparation of CuO nano particles, they were immobilized into the porous matrix of sodium alginate. The drying process formed a very porous structure that is useful for enhancing of adsorption activity. Produced CuO particles were characterized by X-ray diffractometery (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and BET for measuring the surface area. The prepared materials were then used as adsorbent in the removal of toxic metal ions in aqueous solution. To optimize the adsorption system, the effect of various parameters such as adsorbent... 

    Investigation of Mechanical Properties and Durability of Alkali-activated Slag Concrete Lightened with Scoria and Its Microstructural Study

    , M.Sc. Thesis Sharif University of Technology Mahmoudzadeh Vaziri, Nima (Author) ; Khaloo, Alireza (Supervisor)
    Concrete has long been one of the most widely used materials in the world. Cement, as a major component of concrete, due to the use of fossil fuels in its production process, emitting greenhouse gases such as carbon dioxide, which cause air pollution and environmental issues such as climate change. On the other hand, the wastes of industrial factories such as slag of the Blast furnace, due to their large volume and lack of sufficient space for storage of these wastes, lead to the release of these wastes that have alkaline structures into enviroment, causing environmental pollution Such as embankment pollution. Alkali-activated concrete has prevented the release of these pollutant into the... 

    Effect of bentonite binder on adsorption and cation exchange properties of granulated nano NaY zeolite

    , Article Advanced Materials Research ; Volume 335-336 , 2011 , Pages 423-428 ; 10226680 (ISSN) ; 9783037852460 (ISBN) Amir, C ; Mohammad, K ; Javad, A. S ; Sareh, A. A ; Sharif University of Technology
    In order to investigate the effect of bentonite binder on adsorption and cation exchange properties of granulated nano NaY zeolite, the adsorption of Xe and N 2 and removal of Sr 2+ ion from aqueous solution was studied. The results showed that increase in bentonite content of granules from 20 to 40 weight percent caused increase in the rupture load of granules by 232%, decrease in BET surface area by 66% and lower the Sr 2+ uptake percentage by 35%. The Henry's law constant, heat of adsorption, effective crystal diffusivity as well as activation energy of diffusion of Xe over granulated nano NaY with 25% bentonite was also measured by pulse chromatography method. Obtained results were... 

    Removal of humic acid from aqueous solution using photocatalytic reaction on perlite granules covered by nano TiO2 particles

    , Article Journal of Molecular Liquids ; Volume 242 , 2017 , Pages 357-363 ; 01677322 (ISSN) Joolaei, H ; Vossoughi, M ; Rashidi Mehr Abadi, A ; Heravi, A ; Sharif University of Technology
    Humic acid (HA) constitutes a large portion of natural organic matter (NOM), and is the main precursor of toxic and cancerogenic Trihalomethanes compounds, formed during chlorination of drinking water. Therefore, it is essential that the humic acid be eliminated from water before treating it. The present study aims to investigate the photocatalytic degradation of humic acid (HA) using TiO2 nanoparticles immobilized on perlite granules (TIP), irradiated by UV light in a photoreactor. Samples of coated perlites were prepared by a dip coating method using a commercial powder of TiO2. Characteristics of the prepared samples were evaluated by X-ray and scanning electron microscope techniques.... 

    Study of early-age creep and shrinkage of concrete containing Iranian pozzolans: An experimental comparative study

    , Article Scientia Iranica ; Volume 16, Issue 2 A , 2009 , Pages 126-137 ; 10263098 (ISSN) Ghodousi, P ; Afshar, M. H ; Ketabchi, H ; Rasa, E ; Sharif University of Technology
    This paper presents an experimental study on prediction of the early-age creep and shrinkage of concrete with and without silica fumes, trass, ground-granulated blast-furnace slag, combinations thereof, and influences of the proposed Iranian pozzolans. Experiments were carried out under a controlled ambient condition at a temperature of 40° C and a relative humidity (RH) of 50%, and a laboratory ambient condition at a temperature of 20° C and a relative humidity (RH) of 30% in order to collect the required data. Comparisons are made between ACI209-92, BS8110-1986 and CEB1970 prediction models, and an estimation model, based on 28-day results (short-term test method), using the same... 

    A simple granulation technique for preparing high-porosity nano copper oxide(II) catalyst beads

    , Article Particuology ; Volume 9, Issue 5 , 2011 , Pages 480-485 ; 16742001 (ISSN) Ahmadi, S. J ; Outokesh, M ; Hosseinpour, M ; Mousavand, T ; Sharif University of Technology
    A simple and efficient method was developed for fabricating spherical granules of CuO catalyst via a three-step procedure. In the first step, copper oxide nanoparticles were synthesized by hydrothermal decomposition of copper nitrate solution under supercritical condition. Then, they were immobilized in the polymeric matrix of calcium alginate, and followed by high-temperature calcination in an air stream as the third step, in which carbonaceous materials were oxidized, to result in a pebble-type catalyst of high porosity. The produced CuO nanoparticles were characterized by transmission electron microscopy (TEM) that revealed an average size of 5 nm, X-ray diffractometry (XRD), and thermo...