Sharif Digital Repository

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 chromium(VI) removal in contaminated wastewater. A laboratory scale packed bed reactor (PBR) was fabricated and operated to study the bacteria’s feasibility on chromium(VI) reduction and removal. The reactor was packed with polyurethane foam cubes and operated under different feeding and operating conditions of HRT, COD/〖SO〗_4^(2-) ratio and influent chromium(VI) concentration. A maximum chromium removal of 94.6% was achieved in the PBR when operated at an HRT of 24 h with COD/〖SO〗_4^(2-) ratio of .70 and influent... 

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... 

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,... 

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... 

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... 

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... 

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... 

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... 

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... 

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, 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,... 

By increasing of population, migration to urban area and industrial development, the concern of environmental pollution becomes more important. Wastewaters are one of the polluting agents which should be collected, treated and reused in a safe and healthy condition. Generally wastewater treatment systems are classified into two major groups, namely aerobic and anaerobic treatment systems.Anaerobic fixed bed reactors are used for decreasing the organic load of wastewater. Enhancement of microbial retention time by attaching the organisms to packings is the most significant advantage of this bioreactor which increases the removal efficiency of organic materials of strength wastewater.In this... 

Two major challenges facing countries all around the world are the demand for renewable energy resources and treatment of large quantities of industrial and household wastewaters. One of the new and environmentally acceptable methods to produce green energy is Microbial Fuel Cells (MFCs), which has been noted by many researchers in recent years. MFC is a new technology which has the ability to produce green energy along with treatment of wastewater stream, based on oxidation of organic maters through microbial metabolism. In this study we investigated the effects of different cathode chamber parameters on operation and efficiency of a two chamber MFC at laboratory scale. These parameters... 

A microbial fuel cell (MFC) is a bioreactor that utilizes chemical energy in the chemical bonds of organic compounds to electrical energy production through catalytic reactions of microorganisms under anaerobic conditions. In this study, the performance of a dual chamber, mediator-less anode, graphite electrodes MFC employing mixed consortia as anodic inoculums and using a combination of formalin and glucose as substrate was investigated. Different MFCs with different concentration of formalin and fixed concentration of glucose was operated to elucidate the difference in power generation and removal of formalin as an industrial pollutant under similar operating conditions [ambient pressure;... 

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... 

Current research studies the effect of electromagnetic field on reducing precipitation on membrane surface in reverse osmosis. Reverse osmosis is one of the most widely applied methods for water desalinization. Despite its advantages over other desalinization techniques, suffers from shortcomings such as blockage of membrane surface. Use of magnetic fields for reducing precipitation in process equipment, the so-called magnetic treatment, has been studied and practiced for decades. This research intends to study the effect of electromagnetic field on water and its mineral content, and the possibility of its application as a method for reducing precipitation and blockage in reverse osmosis... 

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 alkali-catalyzed transesterification. The used frying oil was originally a mixture of various oils obtained from vegetables that are native to Iran. The design of experiments was performed using a 5-level-5-factor central composite design coupled with response surface methodology in order to study the effect of factors on the yield of biodiesel and optimizing the reaction conditions. The factors... 

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...