Sharif Digital Repository

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,... 

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... 

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... 

Regarding decreasing resources of fossil fuels and their increasing costs in addition to their environmental pollutions, today, producing bio fuels from wastes such as lignocellulosic materials is of great interest. A fundamental stage in conversion of lignocellulosic materials into bio fuels, such as bio ethanol, is the enzymatic hydrolysis of these materials to produce reducing sugars. Researches have shown high costs of this stage. Optimization of enzymatic hydrolysisconditions is a major step in economization of this process.In this work corn hull is used to produce glucose. Corn hull is a kind of lignocellulosic material that due to high carbohydrate content is used as substrate. Our... 

Emission of aromatic and aliphatic compounds to atmosphere is a major environmental concern for many urban societies. Catalytic oxidation of volatile organic compounds (VOCs) is an efficient and low operating cost technology for reduction of air pollution.
First, dispersed copper oxide nano-catalysts supported on almond shell-based activated carbon were prepared for catalytic oxidation of toluene in air. The Response Surface Methodology (RSM) was used to express the catalyst removal efficiency in terms of catalyst metal loading and calcination temperature. Calcination temperature had a significant effect on the catalyst activity only at high metal loadings (upper 8% wt.). Two different... 

One of the most significant problems of oil regions is salinity of the produced water extracted from the well. Penetrating the produced water through the surrounding environments of the oil well in recent years, plenty of environmental problems, especially agricultural ones have been caused in these areas. According to the increasing trend of water salinity during the time, one of the urgent action in the oil industry of the country should be finding a way to reduce the amount of dissolved salt in the produced water. The purpose to this project has been representing a more appropriate configuration for desalination of the produced water. Therefore, the water sample containing less than 70000... 

Biodegradation is an effective method for removal of hazardous organic compounds such as styrene and ethylbenzene from petrochemical wastewaters. Although using this method for wastewater treatment meets (satisfies) the industrial standards, still these methods have significant disadvantages. Active sludge systems can not be effective enough due to the volatility and recalcitrance of styrene and ethylbenzene and a significant amount of volatile organic compounds exists in the discharging air. In order to reduce or totally remove this amount of pollutants in the discharging air, Membrane Bioreactors are used. One of the main problems of these systems is membrane fouling. In this thesis the... 

Trash production in Iran is increasing. The majority of trash is being buried and that induces the emission of methane gas (CH4), which is a greenhouse gas. In this thesis, the aim was mostly to remove methane from greenhouse gases by applying several cheap and abundant substances. For this purpose, a biofilteration system was provided. It has been tested using two packings: straw and plastic. To provide the necessary materials for bacterium growth, a nutrient solution was used. The results of this work have revealed that plastic proved to be more effective than another substance and the removal percent obtained was about 61%. The result for straw was 42%. Furthermore, the experiments were... 

If wastewater is not properly treated, then the environment and human health can be negatively impacted. These impacts can include harm to fish and wildlife populations, oxygen depletion and contamination of drinking water. In the typical wastewater treatment process, the goal of primary, secondary and tertiary effluent treatment is to reduce or remove organic matter, solids, nutrients, disease-causing organisms and other pollutants from the treated wastewater before it is discharged to a body of water. Biological methods for wastewater treatment are much preferable for being more economical and environmentally friendly. Biological treatment of wastewater using algal-bacterial culture... 

The increase in CO2 concentration and its effect on ecosystem and global warming make carbon sequestration inevitable for now and future. Ex-situ carbonation of mineral ores is one of the studied sequestration methods. This method is permanent and safe in comparison with others. This process is carried out in four steps and two phases in this dissertation. At the first stage magnesium was extracted from its mineral silicate ore (Mixture of serpentine and olivine) by hydrochloric acid (HCl) and was dissolved in liquid phase as ion. After that the resultant leachate of extraction step was purified from unwanted ions extracted from minerals in two steps by precipitation formed by increasing pH.... 

Biodiesel can be a good alternative for fossil diesel since it isrenewable, biodegradable and non-toxic. Also, in comparison with fossil fuels, it emits less air pollutants and greenhouse gases.Findacost effective and environmentally friendly wayforcontinuousproductionofbiodieselcanaddressmany of our environmental concerns. In this study, we applied heterogeneous alkali-catalyzed transesterification as method and used waste frying oil as a low cost feedstock for biodiesel production. The project was performed in two phases. First, experiments were conducted in astirred reactor to finda suitable catalyst which was strontium carbonate calcinated for 3:24 hours in 975̊C.
RPB(rotating... 

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... 

Goal of this project was study of local microorganism ability in remediation of hydrocarbon contamination exists in contaminated soil around Sarkhun refinery.In first phase of this study, evaluation of bioremediation performance was done. Using a standard method in a 20 days period, the ability of local microorganism exists in contaminated soil was studied. In this study, 3 different nutrient ratios for 7 samples, 21 experimental samples, were used. Nutrient ratios as C:N:P were: 100:0:0, 100:5:1, and 100:9:1. Results showed that in this remediation period, minimum remediation efficiency in all samples with nutrients is 50% and also the best nutrient ration is 100:5:1. An empirical model was... 

Some of the thermal power plants use heavy fuel oil as an auxiliary fuel instead of the fuel gas, especially in the cold seasons. In these plants, in order to reduce fuel viscosity, heavy fuel oil is heated in several stages including fuel storage tank, connection lines and oil supply to burner by heat exchange with returned steam from the turbine, which can lead to fuel leakage into the condensates. This contamination is in addition to the contamination that has resulted from leaking seals on steam driven equipments, such as pumps and turbines. Reusing these contaminated condensates as boiler feed water can lead to coking of hydrocarbons and deposition of a hard scale on boiler tube walls.... 

According to, increasing use of energy in the world, issues such as increasing reenhouse gas’ emission, rising temperature on planet earth and air pollution have appeared Carbon dioxide is a major greenhouse gas that has a significant impact on increasing the temperature of earth. In recent years, attentions to carbon dioxide capturring and sequestration technologies have been increased. In this project molten carbonate fuel cell which is used as a new method for separating carbon dioxide from gaseous compounds of combustion process, is discussed. The aim of the project is to, investigate technical and
economic feasibility of using molten carbonate fuel cell for separating carbon...