Sharif Digital Repository

A proper process selection has an important role in optimal operation of designed plants at exploitation time. The aim of this research is to provide software for the optimal process selection of municipal wastewater treatment plants in Iran which is a multi criteria optimization process. For this reason this project has been defined to establish a unique procedure for process selection aiming to help design engineers to find optimal process combinations. The main reasons of this case study include: special geology, the culture of people and economic conditions. Heretofore, numerous efforts have been done on optimal wastewater treatment process selection. But in most of them selection has... 

In this thesis, an algorithm is developed based on Multi Criteria Decision Analysis (Analytical Hierarchy Process, TOPSIS) combination with Fuzzy logic, and then user-friendly software with a GUI was designed and introduced. By using this method, it becomes possible to compare processes based on their ratings and users desired importance, and finally determine the closest process to the user ideal choice  

Because of production of large volumes of Produces Water during oil exploration, it is necessary to purify this water for reuse or discharging to environment. Thus, finding a suitable method for removing contaminations seems necessary. In the present study, removal of soluble and dispersed organic contaminants from produced water by Dissolved Air Precipitation/ Solvent Sublation has been studied. Combination of floatation by dissolved air and extraction with solvent has been used for removal of organic compounds in order to study simultaneous effect of both methods on removal efficiency. Samples used in the experiments were tested in two groups: the first group was synthesized samples of... 

Water is used as a key material in different processes of chemical industries. Considering abundant demand of chemical industries for water, pollution that threats this valuable material and the fact that there is currently no proper substitute for water, an urgent necessity is felt for economic utilization of water in industrial processes and optimal use of water resources. A variety of methods have been developed for analysis of water consumption in industrial processes, amongst are Pinch methodology and Mathematical Programming approach. In this thesis a Petroleum Refinery has been preferred as a case study in which optimization of water consumption in the aforementioned petroleum... 

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... 

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,... 

In this thesis was investigated the effect of solid retention time (SRT), Hydraulic retention time (HRT), activated carbon and suspended carrier on styrene and ethylbenzene biological removal and also on membrane fouling. In addition to the typical analysis (COD, MLSS, MLVSS, and SVI), the flocculation ability, sludge particle size distribution (PSD), FTIR analysis, excitation-emission matrix (EEM) fluorescence spectroscopy, soluble microbial product (SMP), extracellular polymeric substance (EPS), microscopic observations, microbial activities, microorganism population, and filamentous bacteria are considered to determine sludge characteristics. This study was done in five sections: in the... 

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... 

The goal of this research is to optimize the parameters of a process through which it would be possible to separate and recovery a considerable portion of ammonia nitrogen available in anaerobic digestion effluent slurry. To achieve this goal, after completing the construction of batch setup (including anaerobic reactor and stripper) and after the digestion of (cow and poultry manure) , the experiments of separation on amounts 9, 10, 11 and 12 of pH and on temperature 14, 25, and 38 celsius degrees were done on digested slurry. Then, the resulting equations of the experimental outcome fitting were used in the optimization of parameters. The results showed that the amount of the parameters of... 

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... 

Most countries regard to parameters such as equipment, cost, facilities, manpower, geographical conditions and environmental regulations select one (or combination) of the methods of burning in incinerators and burial in the landfill for municipal solid waste management. Both methods have undesirable environmental effects and are dangerous. Composting is another proposed option for solid waste management that is more consistent with the environment. In this process, different bacterial species transfer organic materials under aerobic conditions to the products such as CO2, H2O, minerals and compost. One of the effective and economical method for solid waste management is vermicomposting... 

Submerged Membrane Electro-Bioreactor (SMEBR) was invented to increase the efficiency of Membrane Bioreactor (MBR) systems by reducing the fouling amount. The objective of this study was to understand the physical effects of Electrocoagulation (EC) method on membrane fouling and compares the critical flux number by applying electricity under different conditions and without any electrifying. This paper measured the critical flux, that obtained under different process condition including different MLSS concentrations (8000 ppm, 5000 ppm, 2000 ppm), different current densities and electrodes distance. The best result was obtained during highest CD (30 mA/cm2) and lowest distance of electrodes... 

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... 

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...