Sharif Digital Repository

Microbial fuel cell (MFC) has attracted a great attention in the recent years due to its advantage of simultaneous energy generation and pollution removal. However, utilization of MFC technologies a challenging issue because of the low energy output and high expenses. Generally, using ion exchange membrane in MFC contributes to a large proportion of the construction costs. Without using a membrane, oxygen intrudes to the anode chamber which will inhibit the anode reaction and decreases the coulombic efficiency. As a solution, using less expensive membranes can facilitate the commercialization of MFC technology.
In this study, soil cylinder and earthen plate were examined as low cost... 

In this study, biodiesel production using enzymatic method for transestrification of castor oil was investigated. It was found that the yield of biodiesel production is affected by methanol to oil molar ratio, temperature, enzyme amount, water content and reaction time. Effective factors were determined first, using two-factorial design method. Methanol to oil molar ratio was found as the most effective factor. Response surface methodology coupled with central composite design was utilized for statistical modeling of enzymatic biodiesel production and the reaction time was found as a non-significant factor. In another attempt, three factors including methanol to oil molar ratio, temperature,... 

Petroleum based products are the major sources of energy for industry and daily life, With the development of social economy, the demands of the oil have increased dramatically. Petroleum hydrocarbons can cause environmental pollution during various stages of production, transportation, refining and use. Releases of petroleum products(e.g., gasoline, diesel, fuel oil) from aboveground and underground storage tanks or transport pipelines are the major causes of the environment pollution.The major constituents of petroleum hydrocarbons are biodegradable. Many soil microorganisms transform oil hydrocarbons into nontoxic compounds or mineralize them to inorganic compounds. In situ... 

In this project, tomato processing waste has been considered as a raw material for bio-refinery applications. Some products from tomato wastes that are usable, economical and environmentally friendly have chosen after lots of studying on researches in regards of producing valuable materials from tomato waste. I’ve used “Superpro designer” software for economical evaluation and determining the possibility of this practice for industrial applications. Beside the tomato paste factory, the process includes one unit of Lycopene production. In addition to Lycopene production, it is possible to produce fertilizer from residues and using them as livestock food or producing energy for the output... 

Microbial Electrolysis is a new method for producing Biohydrogen from oxidation of organic materials by microorganisms. Generally, this process is depended on two different kinds of energy source containing Organic Material Oxidation by bacteria and Electricity. In this specific study, landfill leachate, extracted from ARADKOOH Tehran Iran was used as a carbon source and effective parameters in Microbial Electrolysis Cell were scrutinized for increasing the hydrogen production and efficiency of COD removal in wastewater. Two H-type rectors with 300 ml of volume in each side were used during the experiments. Various amount of voltages started with 0.4 (V), were tested in the system and it was... 

The main objective of this research was to evaluate the application of a new strain of Brevundimonas naejangsanensis which is newly identified sulfate-reducing bacteria (SRB), in bioremediation. A laboratory scale packed bed reactor (PBR) was fabricated and operated to study the new bacteria’s feasibility on SO_4^(2-) reduction. The reactor was packed with polyurethane foam cubes and operated under different feeding and operating conditions of HRT, COD/SO_4^(2-) ratio and salinity. A maximum SO_4^(2-) reduction of 73.6% was achieved in the PBR when operated at an HRT of 12 h with SO_4^(2-) concentration of 670 mg/L, COD/SO_4^(2-) ratio of 1 and salinity of 3%. The results show that this... 

Microbial electrolysis cell is a novel technology for hydrogen production. The biggest challenges for this new technology are low rate of hydrogen production and high investment cost.
In this research, catholite condition was investigated for increasing the rate of hydrogen production. Low price stainless steel was used as cathode electrod. The microbial electrolysis cell operated applying 1.3 v external voltage. Basic pH was found to be the best condition for maximum rate of hydrogen production, where the average rate of hydrogen production was 100.006 1.866 L/m3.d. However, the hydrogen production rate for the acidic and neutral cathodic condition, were 92.89 1.13 and 91.845 1.485... 

Environmental issues are more and more considered because of increasing environmental pollution along the industrial growth. In recent years Microbial Fuel Cells (MFCs) have attracted attention of many researchers as a renewable source of clean energy. In this research, wastewaters of purified terephthalic acid (PTA) plant and polyethylene terephthalate (PET) plant were examined in MFC.
Voltage generation in the PTA MFC cycle indicated two steady phases. Produced power was 31.8 mW/m2 (normalized per cathode area) and calculated Coulombic efficiency was 2.05 % for COD removal of 74% during 21 days. Concentration changes of each pollutant indicated that acetic acid (AA) and benzoic acid... 

Effective parameters on decolourization of Sumifix Black B or Reactive Black 5 (RB5) by the extracted peroxidase from Coprinus Cinereus NBRC 30628 in a bioreactor have been reviewed in this master thesis. These parameters were such as hydrogen peroxide concentration, pH of dye solution, enzymatic activity and hydraulic retention time. All of these parameters were optimized in such condition that enzyme solution was added to bioreactor at the initial time of reaction. Optimum concentration for hydrogen peroxide, pH, dye concentration, and hydraulic retention time in above mentioned condition of reactor were 96.1 mM, 8, 40 ppm, and 60 min, respectively. It is worth to note that the higher... 

Biodiesel as an alternative fuel for fossil diesel has many benefits such as reducing regulated air pollutants emissions, reducing greenhouse gases emissions, being renewable, biodegradable and non-toxic. In this study, used frying oil was used as a low cost feedstock for biodiesel production by sodium silicate as an alkaline catalyst in transesterification reaction in order to optimize the conditions of biodiesel production. The factors studied were: reaction temperature, molar ratio of methanol to oil, catalyst amount and catalyst recovering. The optimum conditions of reaction obtained as follows: methanol to oil molar ratio of 7:1(mol⁄mol), catalyst amount of 3% w/w and reaction... 

In this project, quantification of sulfide ion was investigated based on peroxidase enzyme inhibition. The fungal peroxidase was obtained from the liquid culture of Coprinus cinereus NBRC 30628. Two different biosensing systems were suggested for sulfide ion measurement: (1) An amperometric inhibition peroxidase biosensor proposed for determination of sulfide by in situ bulk polymerization of acrylamide for immobilization of peroxidase on screen-printed carbon electrode. Measurements were performed using phosphate buffer solution as a supporting electrolyte in the presence of hydroquinone as a mediator. Identification method was based on reduction of generation current, caused by hydrolysis... 

Electrocoagulation is one of the new methods for water and wastewater treatment that is carried out by electrical current. This method is easily applicable to a variety of wastewater. it is highly efficient in organic matter removal and other toxic are and dangerous pollutants.
This study dealt with diesel and COD removal by Electrocoagulation method. Energy consumption, electricity consumption, and the amount of sludge produced by this method was evaluated. Experiments were conducted in a 2 L reactor, consisting aluminum and iron electrodes.The distance between anode and cathode was 5 cm. To evaluate the efficiency of electrocoagulation method, parameters including: pH, time,... 

Critical flux is an important parameter in membrane bioreactors, which studying it can give a better understanding of treatment by these bioreactors and make utilizing them easier. In this study, the effect of some sludge properties like it’s concentration, sludge volum index, concentration of protein and carbohydrate in EPS and SMP and the effect of some operating conditions like aeration flow rate and rest mode on critical flux in a submerged membrane bioreactor are investigated. In addition to comparison of TMP-t figures drived from flux step experiment, the hystersis figures are also compared. Finally, two long term experiments at two sub critical fluxes are done in order to study the... 

Odor caused by the release of volatiles from refinery waste, causing environmental pollution and health hazards may occur. Refinery wastewater project in Saeakhs (Khangiran) has been studied. Contaminated water in evaporation ponds at the plant accumulates due to the large volume of incoming water and slow evaporation in summer the water will smell unpleasant. Odor from the ponds due to wind scattered around the refinery and residents will be put at risk. Several tests to identify the source of the odor was designed and implemented. Among these methods, microalgae growth, the import of oil products such as aromatic compounds or mercaptans, and bacterial growth, for each of the hypotheses... 

The enzymatic transesterification of castor oil with methanol in a solvent free media is carried out using lipase catalyst. The influence of several operation conditions on the production of biodiesel was analyzed i.e. the amount of enzyme, molar ratio of methanol to castor oil, reaction temperature and reaction time. It is observed that with increase in molar ratio, reaction time and enzyme amount, the amount of product (biodiesel) increased. When reaction temperature increased, the amount of biodiesel increased firstly and then decreased. The optimum conditions for the reaction were as follows: enzyme amount 300 mg, molar ratio of methanol to oil 9:1 and temperature 55°C. The maximum... 

Due to their enormous CO/〖NO〗_x removal capabilitiy, catalytic converters are deemed as indispensable parts of modern vehicles. These converters are comprised of a bundle of parallel tubes which their internal walls are wash-coated with a catalyst such as platinum or rhodium. The typical geometry for the tubes’ cross-section is honeycomb. In this project, the effect of tube cross-section geometry on CO/〖NO〗_x removal performance of catalytic converters is studied. In this respect, a three-dimensional model consisted of incompressible flow, advection-diffusion, and surface reaction was developed. Candidate geometries were triangle, square, honeycomb, and circle. The results show that as the... 

Ground water is one of major resources of drinking water in Iran and thus, its quality (in terms of absence of pollutants) is a matter of great importance. The main goal of this research was to investigate the pollution concentration in the Ground water and soil in the fields near South Pars Gas Complex Co. (SPGC). The second goal was to determined the source and measure the distribution of the pollutants (in case of presence) and determine potential risks caused by them. The first step was to perform experimental tests in the two regions. In SPGC region, a number of wells were chosen for sampling according to the direction of Ground water movement. All samples were taken using two EPA... 

Using microbial electrolysis cells (MEC) for hydrogen production has been considered in recent years. So far, synthetic wastewaters containing substances such as glucose and acetate have been mainly used in MECs and industrial wastewaters have not been widely studied. Food industry wastewater is a suitable choice for application in microbial electrolysis cell due to its biodegradable materials. In present research, dairy wastewater and sludge collected from UASB reactor of Iran Dairy Industries company, Tehran were initially used in a dual chamber microbial fuel cell until a stable voltage was generated .Afterward, the system was converted to a MEC applying a predetermined voltage. The... 

In this project, Olive Mill Wastes (OMW) has been considered as a raw material for a bio-refinery. The project is consisted of a design section using SuperPro Designer software and an experimental section. The biorefinery was designed using the software after conducting a survey on the production of different value added material from OMW. The designed process consisted of xanthan gum, methane gas and agriculture fertilizer production. As much as 15000 L of the diluted OMW (to 50% of the initial concentration) is purified and 88 Kg xanthan gum (in 7 days), 2840 Kg methane gas and 200 Kg fertilizer in 25 days are produced at the same time.
In the experimental section, effect of applying... 

Microbial enhanced oil recovery (MEOR) is a collection of techniques that utilize microorganisms and their metabolic products to improve the recovery of crude oil from reservoir rock. From the advantages of this method, independency to the oil price and environmental benign can be mentioned. Many mechanisms have been proposed to contribute on MEOR, but still there is no enough knowledge about the mechanisms that causes inabilities in manipulating the process to get more oil production.
In the present study, the effect of a native type of bacteria, Enterobacter cloacae, on the glass surfaces wettability which were aged in expose of model oil with different asphaltene concentration was...