Sharif Digital Repository

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,... 

The cosmic ray astronomy was born in 1937 when Victor Hess flied with his balloon to the height of 17,500 feet. He found that the cosmic rays come from out of atmosphere. There are three fundamental questions from that time. The goal of all cosmic ray's experimental activities and related theories is finding out the answer of these questions. The first question is about the energy and composition spectrum of cosmic rays. The second one is finding the sources which can product the very high energy particles such as the protons with the energy of 1021eV found in some observatory such as AGASA and Haverah Park. The last question is the process of diffusion of cosmic rays in the galaxy. One of... 

Automation of the software development process is the software engineers' final goal, but with the current facilities and knowledge in software engineering, it is not possible to automatically generate the whole software. Usually all the software in a specific domain contain common behaviors, which by careful exploration of these common behaviors and automation of code generation in these sections, the cost and time of projects' execution can be reduced. According to Model Driven Development (MDD), the first step in software development is creating appropriate models. For creating models, metamodel is required; therefore, we need to create a specific motamodel for the chosen domain or use... 

With the growth of the urban population and the increase in private car ownership, negative implications of transportation, such as traffic congestion and environmental pollution has increased. A good solution to this problem is development of traffic infrastructures. However, it is not sufficient by itself and better management strategies for solving these problems are needed. One of the related approaches, is high occupancy toll lane. The main purpose of this study is modeling user’s mode choice behavior in the presence of high occupancy toll lane and pricing some highway lanes in Tehran. Another important purpose of this study is to find affective factors that have an influence on users... 

Textile industrial wastewaters are one of the most important sources of environmental contaminants. In the recent years, use of advanced oxidation processes, by producing highly active and reactive components such as hydroxyl radicals has been proposed. The aim of this research is oxidative degradation of methylene blue dye using Cu-nanoparticles immobilized on a polymer support with H2O2 as an oxidant reagent.In general, oxidative degradation of methylene blue with hydrogen proxide in the presence of immobilized CuO nanoparticles on a polymer support as the catalyst was studied. We used polyamidoamine (PAMAM) dendrimer as the polymer support for nanoparticles. fourth generation of PAMAM was... 

Underground 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 underground water and soil in two regions: Dasht-e-naz in Sari and the fields near Sarkhoun gas refinery. The second goal was to determine 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 Sari's Dasht-e-naz region, a number of wells were chosen for sampling according to the direction of underground water... 

This study focused on the investigation of bioleaching of heavy metals from incinerator ash using Thiobacillus thiooxidans. Eight factors were examined for their significance on bioleaching using a Placket-Burman factorial design. Four significant variables (pulp density, Initial pH, sulfur Concentration and inoculation amount) were selected for the optimization studies. The combined effect of these variables on metal bioleaching was studied using a central composite design. Second order polynomials were established to identify the relationship between the recovery percent of the metals and the four significant variables. The optimal values of the variables for maximum metals bioleaching... 

Over 90 percent of the wastewater treatment systems use activated sludge which, yields to increase in organic loadings, these systems do not have appropriate performance. For upgrading of these systems a UASB reactor has been used prior to the activated sludge system, to improve the system performance and also reduce the excess sludge production. A membrane was also used instead of the sedimentation tank, to betterment the effluent quality. COD influent concentration was about 600 to 2400 mg/l, up to 98 percent of COD reduction obtain in this system. Also excess sludge reduction was over 90%. Such a system upgrading will increase treatment capacity by factor of 5. As it was shown, for UASBR,... 

This research was done in order to test the capability of endemic microorganisms in treating hydro-carbonic pollutants found in the soil specimens of Assaluye industrial region. To find the optimum conditions for treating the contaminations, we tried several amounts of substrate as well as temperature and humidity. The total concentration of hydrocarbon compounds in polluted soil samples was measured by both infrared spectrometry and gas chromatography, in treatment process after extraction. The results show that, having 50mg substrate per 1kg of contaminated soil added and keeping humidity at 11%, in a 60-days course the level of initial pollution decreased by 60%. 10 degrees increase in... 

Activated sludge systems are widespread biological wastewater treatment systems that have a very complex and nonlinear dynamics with a wide range of time constants and, as a consequence, are difficult to model and control. On the other hand, using neural networks as function approximators has provided a reliable tool for modeling complex dynamic systems like activated sludge. In this study a multi-input multi-output neural network model predictive controller (NNMPC) is developed and tested based on the basic control strategy of a benchmark simulation model (called BSM1) suggested by european co-operation in the field of science and technical research (COST) actions 682/624. The controller... 

Due to the large portion of organic fraction of municipal solid wastes in Iran, the needing for stabilization and treatment of this waste is obvious. An appropriate method for treatment of these wastes is anaerobic digestion. By skimming through open literature which are investigated about anaerobic bioreactors, declared that despite the benefits of thermophilic bioreactors over mesophilic ones, (more destruction of pathogens, more removal of volatile solids, more production of biogas and greater resilient to organic loading rate shocks) but because of more difficulties in controlling of thermophilic bioreactors, most studies have been done in mesophilic state. This motivated us to a deeper... 

In this study as representatives of alkenylbenzenes and mono-alkylbenzenes respectively were considered individually and as binary mixtures. It was observed that styrene, and ethyl benzene were inhibitory types of substrates across the tested concentration ranges. Thus, biodegradation kinetic is well described by the Haldane model. Kinetic parameter's assessments from single substrate degradation tests and these parameters were used to predict possibly interaction factors achieved from dual substrate experiments. The achieved outcomes from mixture of experiments revealed that the ratio of depletion for each substrate is affected by the presence of the other. It was also inferred that ethyl... 

Nanotechnology as an interdisciplinary science is used in many fields. The use of nanomaterial, make new opportunities in the industry. However, safety issues and environmental risks of the consequences of their use in various applications are the matters of concern. Because of the new emergence of this technology, it is essential that all aspects including possible harmful effects on the environment will also be considered. One way to remove the nanoparticles, is electrocoagulation method, assemble nanoparticles into larger particles with an electric current. In this study, the removal of titanium dioxide nanoparticles, due to its high use in the industry, with electrocoagulation method and... 

Sarcheshme Copper refinery is using ion exchange columns to supply deionized water to the refinery. Every day, 240 cubic meters of waste water from ion exchange columns process are released in nature. The main purpose of this research is to use membrane distillation to purify this wastewater, which reduces the fresh water requirement and at the same time prevents environmental pollution. Membrane distillation technology is capable to purify the high salinity wastewater that other conventional membrane technologies are not able to purify. In this study, the PTFE membrane was used due to its high permeability and low surface energy with pore size of 0.22 μm and membrane thickness of 0.2 to... 

With the increasing population and expanding urbanization and changing consumption patterns and relative prosperity increases, the amount of waste generated has increased significantly. So the municipal waste management as one of the challenges that lie ahead for municipal and state has become. Therefore, different approaches have been proposed to solve this problem. In the past government used landfill or incineration program for waste management. Given the risks to the environment and human health are two ways to create and large amount of biodegradable solid waste, composting seems to be good approach for waste management. With using the process on an industrial scale by municipalities,... 

Nowadays, increased pollutants in the air threat the society health condition and Volatile Organic Compounds (VOCs) are the most hazardous ones among them. In the present study, catalytic oxidation as a prominent of the VOCs removal method from air, have attracted attentions due to high removal efficiency and suitable kinetic reaction. Because of its common industrial applications, toluene is intended to be eliminated through a low cost carbon supported catalyst which is synthesised in the laboratory. Construction method, carbonaceous support type, catalyst metal and its load, calcination temperature and time are among influencing design characteristics. A combination of Impregnation and... 

Almost all of the animal slaughter is done in slaughterhouses. Environment concerns about slaughterhouse industries have been increased as increase in their production. In this study, a DAF+SBR system was used for treatment of industrial slaughterhouse wastewater and efficiency of this system was evaluated.In DAF, we used anionic polymer and PAC as coagulant. We reached best composition in 2 ppm of AP and 200 ppm of PAC. After that DAF system run in different pressures to estimate the best operational pressure & A/S. Best operational pressure and A/S is 4 bar and 0.038. After pretreatment, biological treatment by using SBR reactor was carried out. The results of the SBR reactor showed that... 

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... 

Membrane bioreactors (MBRs) are a combination of activated sludg and mebrane technology. MBRs have been widely used as an advanced process for urban and industrial wastewater-treatment in recent years. Membrane fouling is the main issue that limits their performance and therefor, many studies have concentrated on testing different ways to mitigate the fouling. Ozonation process, that has been proved to reduce the MBR fouling, is studied in this project. Ozonation can provide the conditions for flocculation and therefor improves mixed-liqure properties. Ozon at two concentrations, 0.2 and 0.9 mg/lit was tested. Although results show little change in COD (chemical oxygen demand), but membrane...