Sharif Digital Repository

The main purpose of this dissertation was to synthesize nanostructured adsorbents based on the sol–gel and electrospinning methods and implement them to the trace determination of the desired analytes from different matrices. In the first and second chapters, a summary of the sol–gel and electrospinning methods along with a glance on extraction methods are presented. Then, the implemented projects are presented in the consecutive chapters.In the first work, third chapter, silica nanofibers were successfully produced using electrospinning method. In this process, sol–gel was formed during electrospinning and then, the backbone polymer was removed by heating. To obtain a thin layer of silica... 

Transportation services enable economic growth of countries and account as a major part of Gross National Product (GNP) but on the other hand have negative environmental impacts including Greenhouse Gas (GHG) emissions, noise pollution and toxic effects on the ecosystem such as acid rain. The traditional objective of distribution management is usually minimizing economic costs. Given the existing environmental problems, ecological and social effects of transportation should be considered in addition to the conventional economic costs. In this study, a special type of Vehicle Routing Problem (VRP) with a heterogeneous vehicle fleet that in which environmental and traffic considerations taken... 

In this project, silica and polystyrene based interpenetrating polymer networks (IPNs) were used as a sorbent for microextraction in packed sorbent for having both of the polymer’s properties at the same time. Interpenetrating polymer networks were synthesized with the simultaneous method and three different kind of interpenetrating polymer networks were prepared including full-interpenetrating polymer networks, covalent semi-interpenetrating polymer networks and non-covalent semi-interpenetrating polymer networks. To investigate extraction efficiency of prepared sorbents, 41 compounds including environmental pollutants and biomolecules were chosen. Studies showed that interpenetrating... 

Nanophotocatalysts containing metal oxides and oxy-acids based on the nanoporous materials such as graphene, metal-organic-frameworks and carbon nano tubes were synthesized. The photocatalytic properties of the prepared samples were evaluated by the photodegradation of different pollutants in the suspension and emulsion photocatalytic systems. This study demonstrates a new kind of photocatalytic system via utilization of the superior specific properties inherent in Pickering emulsion. We designed the new photocatalytic system using a photocatalytic active component and hydrophobic conducting nanostructures to form the stabilized Pickering emulsion (Pe-bp system). The results revealed that... 

In this research, absorption and oxidation catalytic scenarios were examined using previous studies in the field of SO2 removal. Nanostructures zeolite 13X, 5A zeolite, gamma alumina and activated carbon were purchased, then structure, function and adsorption isotherm of each adsorbent were evaluated in 5 concentrations of 250, 500, 750, 1000 and 1250 ppm of contaminants. Final results showed that zeolite 13X compared to other Nano-adsorbents has higher ability to SO2 absorption, and thus the final tests such as temperature and pressure evaluation were performed on the selected sorbent. To further evaluation, the absorbent curves based on two models of BDST (Bed depth service time) and... 

Because of increase in use of cars in recent years, demands for parking spaces have also dramatically grown. To resolve this issue construction of multi-storey underground car parks has sharply increased. Due to the high level of contaminants emitted by cars in parking lots and also the continuous presence of humen within them, the control of pollution level and parking indoor air quality is a vital matter. Type of ventilation systems including modern and conventional used for ventilating parking lots and also exhaust and supply vents locations are the most important factors affecting contaminants distribution. Thus investigation the performance of the conventional and modern ventilation... 

Today air pollution has become one of the major urban management concerns. Air pollution could have dangerous effects on human health in short time or long time in many situations. Numerical modelling is one of the most applicable among different ways for predicting pollutant concentration like field measurement, physical model in wind tunnel, and simulation. Modelling of pollutant dispersion is a way for estimating concentration and aggregation of the pollutant near the surface and with different distances from pollution source. In different dispersion models, one of simplest is the Gaussian model. In this approach it is supposed that emission plume obeys from Gaussian distribution and is... 

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... 

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... 

The city of Tehran is dealing with air pollution problems for years. Providing a solution for this problem requires information about different pollutants emission sources. In this subjects, emission factors and emission models are essential tools for decision makers. Among different mobile emission sources in Tehran, motorcycles are of high importance. In this project, for the first time in Iran, exhaust gas pollutants emission of 66 motorcycles with different ages and engine displacement volumes were measured according to Euro-3 standard certification procedure. Measurement results showed that none of the tested motorcycles passed the Euro-3 certification limit on CO emission. Calculations... 

Urbanization increases impervious surfaces and therefore reduces land permeability. As a result, higher amount of runoff is produced which leads to environmental degradation and economic loss. Use of pervious/permeable pavements is an efficient approach to reduce runoff volume and improve the quality. In this study, different design methods of pervious/permeable surface are first described using structural and hydrological modules. Then, a software program for pervious/permeable surface design is put forth. Supported by various available design methods (focusing on pervious surfaces in Iran), the software employs structural, hydrological, economic (cost estimation) and qualitative... 

Air pollution is lateral and inappropriate product of industry and technology development that grows along them, unfortunately. Now its domain extended from local and national issues to global issues. For years like other branches of environmental sciences and other scientific fields, scientists apply formulas and mathematical equations. Nowadays, air pollution modeling is fundamental and powerful tool for air pollution studies, especially in prediction of air pollution conditions, pollutants emission and their concentration under different conditions and arbitrary locations. In this research, numerical modeling of urban air pollutants dispersion is discussed. After validation of results,... 

Stormwater-borne solids are a major contributor to water quality degradation. A large portion of water quality impaired surface waters is located in urban areas and stormwater runoff is a major source of contamination. Sediments have been identified as the most widespread pollutant in urban river and streams. Water quality of urban streams in Tehran was characterized by determining the PSD, total phosphorus (TP), orthophosphate, NO3, NO2, NH3, TSS, TDS, heavy metals and turbidity in six storm events and base flow. A total of 45 road-deposited sediment (RDS) samples were collected from three different land-use types (residential, intense traffic and educational) in Tehran for characterization... 

Chlorine is used in large quantities, in urban and industrial installations. Since chlorine is a toxic gas, its dispersion in such environments may have unpleasant consequences. On the point of Emergency Response Planning, it is important to know how such gases disperse. In this thesis, chlorine atmospheric dispersion is studied as an example of toxic dense gas dispersion. Chlorine accidental release from one of the storage tanks of Sohanak water refinery is selected for the case study. Laleh residential town is located in west of Sohanak refinery. According to the prevailing wind direction in Tehran (which is from the west to the east), the influence of the buildings of Laleh town on gas... 

Apatite-coated Ag/AgBr/TiO2 was prepared by deposition of Ag as noble metal to generate electron-hole pairs by extending the excitation wavelength to visible light region, AgBr as photo-sensitizer to increasing yield of photo catalyst, and apatite as adsorption bio ceramic for adsorbing pollutants and micro organisms respectively. The bactericidal experiments in dark media indicated that only novel catalyst show inhibiting growth of bacteria. In this case Transmission electron microscopy image illustrated that catalyst nano particles adhere to the outer membrane of the cell and acts as inhibitor to nourish of bacteria from around media. The mechanism for deactivation E-Coli and B.Sub in the... 

Release of toxic gases and hazardous materials is very dangerous for health of people that presence in near of release places. Whereas if the concentration of some toxic materials is more than a definite limit, it may cause of irreparable hurt to health of people in very short times, hence reduce the concentration of released materials can get the time for refuge in safe sites for people that presence in released site in initial times.
In this paper with use the Computational Fluid Dynamics models the effect of fence in reduce the concentration of dense gases and delay the distribution of these gases has been studied. The two toxic gas (chlorine and methyl-isocyanate ) have been... 

In parallel to the growing of population in Tehran metropolitan, air pollution in this city has become to a major problem. From which high concentration of pollutants have adverse effects on public health, accurate estimating and forecasting of concentrations for several days ahead, can provide the possibility to implement the management measures to reduce hazard and risks. Among the air pollution models, application of statistic models based on neural network in comparison to the traditional deterministic models are easier and less costly. In most studies, static models use a classical single MLP to predict one step ahead. For this purpose ANN models are required to estimate next value of... 

In this research various treatment methods of produce water are discussed and categorized in two groups namely; Basic and advance methods. Four basic treatment methods including; hydro cyclone, flotation, settling and membrane filtration and also four advance treatment methods including; nano filtration, ultra filtration, oxidation and adsorption are considered to compare and to select the most proper ones. To compare the treatment methods a multi criteria decision method namely Analytical Hierarchy Process (AHP) is applied twice to choose the most proper basic and advance treatment methods. The criteria are suggested according to the local conditions of Kharg Island and the similar... 

There are some parameters, which can affect the performance of a combustor less and more, e.g., fuel-oxidant mixing process, turbulence generation, combustion process, and so on. A stoichiometric reaction as a unique reaction, in which all the reactants are consumed to form the stable products, can be categorized as the most economic reaction. The majority of industrial combustion apparatus consumes hydrocarbon fuels and departs from ideal combustion conditions, which expects products like CO2 and H2O. Combustion by-products reduce the combustion efficiency and cause environmental damages and human health problems. To resolve the human health problems and environmental hazardous issues, the... 

The main aim of this project is to develop a model for risk assessment of energy service companies (ESCO) using energy efficiency and emission trading markets. For this purpose, structure of the market has been developed and then by explaining the interactions between ESCO and other members of the market, ESCO's cash flows have been determineded. In the next stage, probability distribution of the cash flows have been extracted and risk assessment have been performed. The differences in energy prices coming from subsidies is the foundation of this market. In this market, ESCO will sell the saved energy rights which has been achieved in the low price level sector to the other sector with high...