Search for: yaghmaei--soheila
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    MTBE Bioremediation Using Ps. Putida

    , M.Sc. Thesis Sharif University of Technology Rahbarsafa, Omid (Author) ; Yaghmaei, Soheila (Supervisor)

    Optimization of Effective Parameters in Biological Extraction of Mo and Ni from Spent Catalyst

    , M.Sc. Thesis Sharif University of Technology Ghojavand, Fatemeh (Author) ; Yaghmaei, Soheila (Supervisor)
    During oil refinement, solid catalysts which contain metals such as aluminum, tungstan, molybdenum and nickel are highly used. Following several times reductions and re-applications, their activity potentiality is decreased in a such a way that they can not be re-used., as a result of which they are treated as solid waste. Based on natural potentiality, microorganisms are defined as convertibles of solid compounds to extractive forms and soluble materials. This project aims at finding other factors that have more impact on biological extraction and determining optimal conditions for biological extraction in order to reach maximum extraction efficiency within discontinuous conditions. The... 

    Theoretical and Experimental Investigations of Bioelectrochemical Processes in Microfluidic Systems

    , Ph.D. Dissertation Sharif University of Technology Mardanpour, Mohammad Mahdi (Author) ; Yaghmaei, Soheila (Supervisor)
    The first attempt of this study was theoretical and experimental investigations of bioelectrochemical processes in microfluidic systems. Besides, novel applications of this technology as a powerful platform for maximum usage of bioenergy were introduced. The feasibility of a microfluidic microbial fuel cell (MFC) as an efficient power generator for production of bioelectricity for implantable medical devices (IMDs) and fabrication of microfluidic microbial electrolysis cell (MEC) for hydrogen medicine were investigated. For the glucose-fed microfluidic MFC, the maximum power density of 5.2 µW cm-2 obtained in this study is 13 fold greater than the power density reported previously for... 

    Elimination of Environmental Problems Caused by Leakage of Electrical Transformers Fluid (Askarel) by Biological Methods

    , M.Sc. Thesis Sharif University of Technology Samadi, Aryan (Author) ; Yaghmaei, Soheila (Supervisor)
    Polychlorinated biphenyls are a group of hydrocarbons that are composed of two benzene rings and chlorine admixture on it. Due to their special properties, these materials were added to oils for years to improve their properties. These compounds have many industrial applications in various industries, such as the production of fluorescent lamps, adhesives, dyes, and especially as a cooling and insulating liquid as the Askarel oil in power transformers. Due to the properties of these compounds, which include stability and bioaccumulation in fatty tissues, the wide use of these substances causes environmental contamination and leads to a variety of cancerous diseases. Among the cleaning... 

    Some Studies on Ability of Aspergillus Niger Mould in Recovery of Heavy Metals from Crude Oil Sludge.

    , M.Sc. Thesis Sharif University of Technology Anahid, Sanaz (Author) ; Yaghmaei, Soheila (Supervisor)
    This study focused on the tolerance of fungi strains including Aspergillus niger, Aspergillus foetidus and Penicillium for different metals (Ni, Co, Mo, V, Mn, Mg, Fe, W and Zn ). Then Aspergillus niger was exposed to mixture of Mo, V and Mn (at a mass ratio of 1:2:6 as approximately present in the spent refinery processing catalyst). The degree of tolerance was measured from the growth rate in the presence of various metals and compared to a control which contained no metals. Effect of type of strains, type of metal and metal concentration on adaptive tolerance of fungus was evaluated. Adaptation experiments with single metals showed Aspergillus niger tolerated up to 1000 mg/l Ni, Zn, 1500... 

    Biorecovery of heavy metals from oil waste water by adapted Thiobacillus Ferrooxidans

    , M.Sc. Thesis Sharif University of Technology Molaei, Sima (Author) ; Yaghmaei, Soheila (Supervisor)
    Acidophilic microorganisms such as Thiobacillus ferrooxidans have the capability to carry out process of biorecovery of heavy metals. Its principle is the microbial production of the sulphuric acid and simultaneous recovery of metals. Acidithiobacillus ferrooxidans derives the energy for their metabolism from ferrous iron oxidation process which can be affected by the presence of heavy metals in the medium. In this study the ability of Acidithiobacillus ferrooxidans, on the biorecovery of heavy metals in shake flask has been investigated The adaptation of the Acidithiobacillus ferrooxidans to a kind of heavy metal such as Nickel, Cobalt, Vanadium, Molybdenum, Tungsten and the mixture of the... 

    Experimental Study of Hydrogen Production from Dairy Wastewater in the Annular Microbial Electrolysis Cell (AMEC)with Spiral Anode

    , M.Sc. Thesis Sharif University of Technology Hassany, Masoud (Author) ; Yaghmaei, Soheila (Supervisor)
    In this project, energy in form of electricity and hydrogen was produced in microbial fuel cell and microbial electrolysis cell respectively. For reducing costs, a stainless steel mesh with graphite coating was used as anode electode. Also for increasing efficiency, anode was positioned in cells in a spiral mode. Efficiency of cells was investigated in batch and continuous mode. In this research, dairy wastewater was used as substrate.This wastewater not only has severe emissions, but also is high energy content. In the field of dairy wastewater treatment and hydrogen production in an microbial electrolysis cell wasn’t observed any article.At the first, wastewater was treated in two... 

    Experimental Investigation of Effective Parameters on Performance of Micro-sized Bio-electrochemical Systems

    , M.Sc. Thesis Sharif University of Technology Mehran, Narges (Author) ; Yaghmaei, Soheila (Supervisor)
    This study is a report on the fabrication of a novel single-chamber micro-structure microbial fuel cell consisting of spiral anode chamber. A 3×3 cm plexiglass plate with 1 mm thickness was used as main body. A spiral microchannel (1 mm in width and 226 mm in length) was cut using a laser beam as an anodic compartment. Two types of microbial fuel cells with the same anode electrode (stainless steel mesh) and different cathode electrodes (stainless steel mesh and carbon cloth) were constructed in order to investigate the effect of cathode electrode material on microbial fuel cell performance. In both batch and continuous mode, higher power density was obtained by microbial fuel cell with... 

    Computational Fluid Dynamic (CFD) of Fixed-Bed Reactor for Bio-treatment of Sulfur from Petroleum Cuts

    , M.Sc. Thesis Sharif University of Technology kharghanian, Hosein (Author) ; Yaghmaei, Soheila (Supervisor)
    Bio-desulfurization is the sulfur removal process from organosulfur compounds by the action of microorganisms (which are capable of removing sulfur). Too many studies have been carried out in the use of biocatalysts for BDS process. In this project, we have used data obtained from a previous experiment in which a trickle bed reactor (diameter: 0.066 m, height: 0.6 m) and a Rhodococcus sp. 12891 starin immobilized on bed particles are used to produce diesel with low sulfur content. Sulfur concentration of inlet diesel is between 200ppm to 540 ppm. parameters of process are recycle Ratio , volumetric flow rate and sulfur content of inlet diesel.
    A mathematical model for trickle bed... 

    Bioleaching of Metal from Electronic Wastes Using Acidithiobacillus Ferrooxidans

    , M.Sc. Thesis Sharif University of Technology Haghshenas Fatmehsari, Hoda (Author) ; Yaghmaei, Soheila (Supervisor)
    The recycling of the secondary resources for the extraction of their metallic contents is undoubtedly environmentally friendly and can be economic. One of the most important secondary resources is the electronic wastes (E-wastes) which has been widely produced as the discarded electrical/electronic devices. The usual physical/chemical treatments of E-wastes not only result in an increase in human health risks and environmental pollution but also lead to the missing of their valuable metallic contents. An alternative method for the recycling of E-wastes is bioleaching which has recently attracted more attention. The advantages of this process are low energy consumption and environment... 

    Investigating Different Methods of Coating the Polyaniline on Anode Electrode and its Effect on Microbial Fuel Cell Performance

    , M.Sc. Thesis Sharif University of Technology Ghasemi, Behzad (Author) ; Yaghmaei, Soheila (Supervisor)
    In this research, different methods of coating polyaniline on the anode electrode and its performance in a microbial fuel cell, and a chemical method for making polyaniline / graphene catalyst on a cathode electrode and its performance in microbial electrolysis cell electrode were investigated. There are two main goals in this study. First, the production of polyaniline and the comparison of the surface morphology of this fiber with other forms of polyaniline on the surface of the electrode and its effect on the performance of the microbial fuel cell and the second, the production of polyaniline / graphene catalyst in the cathode electrode and its comparison with the platinum catalyst in the... 

    Feasibility Study on Isolation of Native Microorganism for Bioleaching of Electronic Waste

    , M.Sc. Thesis Sharif University of Technology Gheshlaghi, Mahraz (Author) ; Yaghmaei, Soheila (Supervisor)
    Accumulation of electronic wastes in the environment is one of the recent ecological problems. This type of wastes contain metallic and non-metallic elements which can contaminate the environment. On the other hand due to the high volume of precious and basic metals within e-waste, it could be considered as a secondary resource. Bioleaching is a suitable method for the recovery of metals from e-waste which, on the contrary to the conventional recycling methods in the industry, is both economically and ecologically efficient. The aim of this research is the isolation of native micro-organism and evaluating its ability in recovering copper from a mixture of computer, cellphone, fax and copy... 

    Optimization of the Capability of Native Microorganisms Isolated from the Landfill of Electronic Wastes in Bioleaching of E-Waste

    , M.Sc. Thesis Sharif University of Technology Arab, Bahareh (Author) ; Yaghmaei, Soheila (Supervisor)
    Given the complex structure of electronic waste and the difficulty of recycling it by traditional methods, the focus is mainly on biohydrometallurgy method, and in particular on bioleaching. To recover metals, various microorganisms are utilized in this method. In light of previous studies, cyanogenic bacteria have been widely used for the extraction of basic and precious metals. Among the species, indigenous microorganisms have a higher ability to resist toxic environments in the bioleaching of metals due to their adaptation by rapid changes in their metabolic system over time. The main objective of this study is to isolate indigenous microorganisms from electronic waste landfill for their... 

    Experimental Study of Biological Removal of Cyanides in the Effluent of Coke Oven of Esfhan Steel Company

    , M.Sc. Thesis Sharif University of Technology Mirizadeh, Shabnam (Author) ; Yaghmaei, Soheila (Supervisor)
    The presence of highly toxic cyanides in the effluent of coke oven of steel industries is considered as a critical problem. Owing to high levels of toxicity, control and removal of cyanide are of great importance in this industry. Biological removal of cyanides by indigenous microorganisms offers inexpensive, safe and environmentally compatible option in comparison with chemical and physical methods. The present study primarily focused on the isolation and purification of the microorganisms which utilize cyanide as the sole source of Nitrogen in alkaline conditions. The isolated bacterial strains were investigated through variety of bacteriological and biochemical reactions as well as... 

    A Study on Soil Microbial Fuel Cell for Producing Energy and Bioremediation

    , M.Sc. Thesis Sharif University of Technology Afsham, Neda (Author) ; Yaghmaei, Soheila (Supervisor) ; Roshandel, Ramin (Supervisor)
    With the current demands in alternative methods of energy production and increased utilization of existing energy sources, microbial fuel cells have become an important field of research. In a microbial fuel cell, organic and inorganic compounds can be oxidized by microbial catabolism at the anode to generate direct electricity. A kind of microbial fuel cell (MFC) is sediment microbial fuel cell (SMFC) consists of an anode electrode embedded in the anaerobic sediment and a cathode electrode suspended in the overlying aerobic water. microorganisms produce electrons by oxidation of organic or inorganic compounds in the sediment at anode electrode, while oxygen is reduced in the water by... 

    Design and Fabrication of Hydrogel Microcarrier for Tissue Engineering

    , M.Sc. Thesis Sharif University of Technology Radaei, Payam (Author) ; Mashayekhan, Shohre (Supervisor) ; Yaghmaei, Soheila (Supervisor)
    Microcarriers (MCs) are an attractive technology with various applications in tissue engineering. In this study, chitosan/gelatin MCs were fabricated with blends of different ratio of chitosan/gelatin, by using a setup containing high voltage electrostatic field and syringe pump. Optimization of blend ratio, voltage and syringe pump flow carried out by the “Design expert” software leads to fabrication of MCs with constant diameter while having various elasticity. Mechanical strength and elasticity of MCs were determined. Human umbilical cord mesenchymal stem cells (hUCMSCs) were cultured on MCs dynamically by using mini-rocher in an incubator. Cells adhesion on MCs were successfully shown by... 

    Biocracking of Heavy Fuel Oil (Mazut) By Native Microorganisms

    , M.Sc. Thesis Sharif University of Technology Chackoshian Khorasani, Alireza (Author) ; Yaghmaei, Soheila (Supervisor) ; Mashreghi, Mansour (Supervisor)
    Biocracking mazut by native capable microorganisms and practically modeling it is one of the new perfect fields of biotechnology in petroleum manufacture. Sampling soil and water sources polluted by petroleum compounds, has caused a new bacterial strain of Enterobacter cloacae (BBRC 10061) has been identified and isolated from soil in Mashhad contaminated by petroleum wastewater and mixture to biodegrade mazut. Using mixed culture isolated from the sources instead of BBRC 10061 makes same results. In aerobic condition, 13% of mazut in mineral medium has degraded for 10 days however amount of degraded mazut varies with process conditions. Study of fixing and floating mazut, application of... 

    Antimicrobial Effects of Iranian Red Sumac

    , M.Sc. Thesis Sharif University of Technology Taheri, Saeede (Author) ; Maghsoodi, Vida (Supervisor) ; Yaghmaei, Soheila (Supervisor)
    The most important desire of all researchers in food industry is decreasing the contamination of foods and increasing their shelf life. Due to harmfulness of chemical preservatives their use has been limited and therefore natural antimicrobials have been demanded. Recently spices have been noticed as natural antimicrobial agents. Sumac is a kind of spice which has antibacterial and antioxidant activities.The aim of this project is to investigate effects of water and alcoholic extracts of Iranian red sumac comparatively on three gram positive bacteria (Bacillus coagulans , Bacillus subtilis, Staphylococcus aureus) and one gram negative (Escherichia coli) by well and disk diffusion method.... 

    Investigation of the Performance of Microbial Fuel Cell Based on Shewanella Bacteria with the Aim of Nanostructured Materials

    , M.Sc. Thesis Sharif University of Technology Davoudi, Omid (Author) ; Yaghmaei, Soheila (Supervisor) ; Sanaee, Zeinab (Co-Supervisor)
    The development of clean, renewable and alternative sources of fossil fuels has increased in recent years due to various factors such as environmental pollution, reduced fossil fuel resources and increased energy consumption. The application of microbial fuel cells is one of the clean energy production methods using renewable sources such as municipal sewage. The microbial fuel cell converts the chemical energy stored in organic materials into electrical energy and simultaneously purifies the sewage. Increasing current density and power density are the most important challenges for microbial fuel cells. In this study, the two biocatalysts of Shewanella Oneidensis MR1 and Escherichia coli... 

    Bioleaching of E-wastes

    , Ph.D. Dissertation Sharif University of Technology Arshadi, Mahdokht (Author) ; Yaghmaei, Soheila (Supervisor) ; Mousavi, Mohammad (Co-Supervisor)
    This research aims to expand comprehensive information about bioleaching of different kinds of electronic waste (E-waste). The selected wastes were computer PCBs (CPCBs), mobile phone PCBs (MPPCBs), television PCBs (TVPCBs), fax machine PCBs (FPCBs), copy machine PCBs (COPCBs) and central processing units (CPUs). At the first step, a comprehensive study made on the E-waste structure. The best method for precious metal digestion analysis introduced, i.e., using aqua regia, hydrogen peroxide, hydrofluoric acid, and boric acid. The economic values of the E-wastes were as follows: CPU> MPPCBs> COPCBs> FPCBs> CPCBs> TVPCBs. Among the metals, gold attributed to the highest value distribution and...