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    Labratoary Studies of Ozonation Pretreatment for Anaerobic Digestion of Waste Thickened Active Sludge

    , M.Sc. Thesis Sharif University of Technology Hodaei Asfahani, Mahdi (Author) ; Vossoughi, Manouchehr (Supervisor) ; Ghasemi, Shahnaz (Supervisor)
    Abstract
    The best method for stabilizing sludge is anaerobic digestion, In addition to reducing the amount of volatile solids; it produces biogas, which can be considered as a sustainable energy source for wastewater treatment plants. However, the most important factor limiting the process of digestion is the sludge hydrolysis, the best way to increase the speed of hydrolysis is to pre-treatment the sludge before entering the digester; One of the most effective pretreatment methods is pre-treatment by ozone gas, This gas, which is highly unstable, quickly reacts with the wall of the bacterial cell and oxidizes it due to its high oxidizing properties And accelerates the process of sludge hydrolysis.... 

    Modeling Gaseous Air Pollutants Concentration in Tehran Using Artificial Neural Network and Land Use Regression

    , M.Sc. Thesis Sharif University of Technology Mirzaee, Mohsen (Author) ; Mohammad Arhami (Supervisor) ; Amini, Zahra (Co-Supervisor)
    Abstract
    In this thesis the hourly concentration of different gaseous air pollutants in Tehran is modeled using Land Use Regression (LUR) and Artificial Neural Network, separately. Both models are provided with the same set of input data; the first step is to find these data. Since traffic affects air pollution, information about traffic conditions is one of the main inputs in air pollution modeling. Therefore, to obtain traffic information, in this thesis, first a novel method is developed to extract and analyze Google Maps traffic data. In this method, image processing is used along with the Geographic Information System (GIS) to count the number of pixels of different traffic colors for each road... 

    Study of the Effect of Ozonation in Reducing Mambrane Fouling

    , M.Sc. Thesis Sharif University of Technology Mashayekhi, Fatemeh (Author) ; Shaygan, Jallaledin (Supervisor) ; Hazrati, Hossein (Co-Advisor)
    Abstract
    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... 

    Copper Selective Leaching from Sarcheshmeh Reverberatory Furnace Dusts

    , M.Sc. Thesis Sharif University of Technology Mohagheghi, Mahdi (Author) ; Askari, Masoud (Supervisor)
    Abstract
    In this study, leaching of Sarcheshmeh Reverberatory Furnace Dust was investigated in the H2SO4-O3 media. Response surface methodology based on central composite face-centered design (RSM-CCF), was applied to optimize the operating parameters. The optimum conditions to obtain the main goal of maximum copper and minimum iron dissolution from dust were identified to be temperature of 30˚C, leaching time of 3hr, initial pH of 0.5, pulp density of 20% and ozone flow rate of 1g/h. The copper and iron concentrations of leaching solution were found to be 27.11 and 0.89983 g/L under the optimum conditions, respectively. The results showed that selective copper extraction from the dust could be... 

    Modelling and Prediction Air Polutants Level in Tehran Using Dynamic Neural Networks

    , M.Sc. Thesis Sharif University of Technology Khosravi, Neda (Author) ; Erhami, Mohammad (Supervisor)
    Abstract
    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... 

    Modeling of Ground-Level Ozone Concentrations in Tehran using CMAQ Model

    , M.Sc. Thesis Sharif University of Technology Hossein Nia, Bardia (Author) ; Arhami, Mohammad (Supervisor)
    Abstract
    Every year, air pollution is causing immense harm to humans and the environment. To cause Air pollution, several factors are involved. Among these are the sources of emissions such as factories, power plants and Cars, meteorological factors such as temperature and wind speed and geographical conditions such as altitude, postal and looming around the area, land slope and soil type region. The aim of this study is to identify factors that affect the ozone concentration in Tehran, which could help identifying other secondary pollutants. For this purpose, a combination tailored to the geography of Tehran using CMAQ-WRF-SMOKE-made programs. This model includes four intervals each of which lasting... 

    Dual catalytic function of the task-specific ionic liquid: Green oxidation of cyclohexene to adipic acid using 30% H2O2

    , Article Chemical Engineering Journal ; Volume 221 , April , 2013 , Pages 254-257 ; 13858947 (ISSN) Vafaeezadeh, M ; Hashemi, M. M ; Sharif University of Technology
    2013
    Abstract
    The sole industrial process which currently used for adipic acid production is nitric acid oxidation of either cyclohexanol or cyclohexanol/cyclohexanone mixture. Emission of greenhouse nitrous oxide (N2O) gas from this process strongly contributes to global warming, resulting in acid rain and ozone depletion. Herein, we report a catalytic application of a novel dual task-specific ionic liquid (an ionic liquid with two catalytic functions) for oxidation of cyclohexene to adipic acid using 30% hydrogen peroxide. The catalyst showed desirable activity toward oxidation of cyclohexene and some cyclic olefins to produce their corresponding dicarboxylic acids  

    Localized surface plasmon resonance sensor for simultaneous kinetic determination of peroxyacetic acid and hydrogen peroxide

    , Article Analytica Chimica Acta ; Volume 762 , 2013 , Pages 87-93 ; 00032670 (ISSN) Tashkhourian, J ; Hormozi Nezhad, M. R ; Khodaveisi, J ; Dashti, R ; Sharif University of Technology
    2013
    Abstract
    A new sensor for simultaneous determination of peroxyacetic acid and hydrogen peroxide using silver nanoparticles (Ag-NPs) as a chromogenic reagent is introduced. The silver nanoparticles have the catalytic ability for the decomposition of peroxyacetic acid and hydrogen peroxide; then the decomposition of them induces the degradation of silver nanoparticles. Hence, a remarkable change in the localized surface plasmon resonance absorbance strength could be observed. Spectra-kinetic approach and artificial neural network was applied for the simultaneous determination of peroxyacetic acid and hydrogen peroxide. Linear calibration graphs were obtained in the concentration range of (8.20×10-5 to... 

    A novel regression imputation framework for Tehran air pollution monitoring network using outputs from WRF and CAMx models

    , Article Atmospheric Environment ; Volume 187 , 2018 , Pages 24-33 ; 13522310 (ISSN) Shahbazi, H ; Karimi, S ; Hosseini, V ; Yazgi, D ; Torbatian, S ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Missing or incomplete data in short or long intervals is a common problem in measuring air pollution. Severe issues may arise when dealing with missing data for time-series prediction schemes or mean analysis. This study aimed to develop a new regression imputation framework to impute missing values in the hourly air quality data set of Tehran and enhance the applicability of Tehran Air Pollution Forecasting System (TAPFS). The proposed framework was designed based on three types of features including measurements of other stations, WRF and CAMx physical models. In this framework, elastic net and neuro-fuzzy networks were efficiently combined in a two-layer structure. The framework was... 

    Degradation of humic acids through heterogeneous catalytic ozonation with bone charcoal

    , Article Reaction Kinetics, Mechanisms and Catalysis ; Volume 100, Issue 2 , 2010 , Pages 471-485 ; 18785190 (ISSN) Mortazavi, S. B ; Asgari, Gh ; Hashemian, S. J ; Moussavi, G ; Sharif University of Technology
    2010
    Abstract
    Catalytic ozonation has recently been used as a new means of contaminant removal from water and wastewater. In this study, bone charcoal (BC), a new catalyst prepared under laboratory conditions, was used to catalyze the ozonation of humic substances (HS) in aqueous solutions. The catalytic effect of bone charcoal and the relevant parameters of this ozonation process (solution pH, temperature, scavenger effect, humic acids concentration and BC dosage) were investigated. In the catalytic ozonation experiments, the degradation kinetics was investigated. The reaction rate and the rate constant were determined. The results showed that using a BC catalyst in the ozonation of HS produced a 1.43-... 

    A numerical study of reactive pollutant dispersion in street canyons with green roofs

    , Article Building Simulation ; Volume 11, Issue 1 , February , 2018 , Pages 125-138 ; 19963599 (ISSN) Moradpour, M ; Afshin, H ; Farhanieh, B ; Sharif University of Technology
    Tsinghua University Press  2018
    Abstract
    Roof greening is a new technique for improvement of outdoor thermal environment which influences air quality through its impacts on thermal and flow field. In order to examine effects of green roofs on reactive pollutant dispersion within urban street canyons, a computational fluid dynamics (CFD) model was employed which contained NO-NO2-O3 photochemistry and energy balance models. Simulations were performed for street canyons with different aspect ratios (H/W) of 0.5, 1.0, and 2.0 such that leaf area density (LAD) of green roofs changed. It was found that roof greening led distribution of pollutants to alter for H/W = 0.5 and 1.0 cases in such a manner that their averaged concentrations had... 

    Copper recovery from reverberatory furnace flue dust

    , Article International Journal of Mineral Processing ; Volume 157 , 2016 , Pages 205-209 ; 03017516 (ISSN) Mohagheghi, M ; Askari, M ; Sharif University of Technology
    Elsevier, B. V  2016
    Abstract
    In this study, leaching of reverberatory furnace dust at Sarcheshmeh was investigated in H2SO4-O3 medium. Response surface methodology based on central composite face-centered design (RSM-CCF) was applied to optimize the operating parameters. The optimal conditions to achieve the principle objectives of maximizing copper dissolution and minimizing iron dissolution from dust were identified to be a temperature of 30 °C, a leaching time of 3 h, an initial pH of 0.5, a pulp density of 20%, and an ozone flow rate of 1 g/h. Under the optimum conditions, the copper and iron concentrations in the leaching solution were found to be 27.11 and 0.90 g/L, respectively. The results showed that selective... 

    Fouling control mechanism by optimum ozone addition in submerged membrane bioreactors treating synthetic wastewater

    , Article Journal of Environmental Chemical Engineering ; Volume 6, Issue 6 , 2018 , Pages 7294-7301 ; 22133437 (ISSN) Mashayekhi, F ; Hazrati, H ; Shayegan, J ; Sharif University of Technology
    Abstract
    In this paper, the effect of ozone on membrane fouling of membrane bioreactor (MBR) systems was investigated. Sludge specification such as soluble microbial product (SMP), extracellular polymeric substance (EPS), viscosity, particle size distribution (PSD), microscopic observations and sludge volume index (SVI) in presence of ozone were determined. Further, EPS, Fourier-transform infrared (FTIR) analysis, excitation-emission matrix (EEM) fluorescence spectroscopy, and gel permission chromatography (GPC) are considered to determine cake layer characteristics. The results indicated COD removal did not show significant difference with ozonation. Ozone also increases the particle size and... 

    Heterogeneous catalytic ozonation by Nano-MgO is better than sole ozonation for metronidazole degradation, toxicity reduction, and biodegradability improvement

    , Article Desalination and Water Treatment ; Volume 57, Issue 35 , 2016 , Pages 16435-16444 ; 19443994 (ISSN) Kermani, M ; Bahrami Asl, F ; Farzadkia, M ; Esrafili, A ; Salahshour Arian, S ; Khazaei, M ; Dadban Shahamat, Y ; Zeynalzadeh, D ; Sharif University of Technology
    Taylor and Francis Inc  2016
    Abstract
    Abstract: In the current paper, the removal efficiency of metronidazole (MNZ) using a catalytic ozonation process (COP) in the presence of magnesium oxide nanocrystals, as a catalyst, was investigated in deionized water and compared with a sole ozonation process (SOP). The influence of several operational factors on both removal processes was evaluated: solution pH, MgO dosage, initial MNZ concentration, and reaction time. Biodegradability improvement, mineralization rate, oxidation intermediates, and toxicity were also studied for the COP. The results showed that MgO nanocrystals accelerated MNZ removal compared to the SOP. The optimum pH for both SOP and COP was obtained at 10 and optimum... 

    Performance evaluation of ultraviolet radiation and ozone disinfection for municipal secondary effluent reuse (Case study in isfahan north wastewater treatment plant)

    , Article Desalination and Water Treatment ; Volume 223 , May , 2021 , Pages 105-113 ; 19443994 (ISSN) Jamalinezhad, M ; Hassani, A. H ; Borghei, M ; Amin, M. M ; Sharif University of Technology
    Desalination Publications  2021
    Abstract
    This study aimed to evaluate and compare the performance of wastewater disinfection systems using ultraviolet radiation (UV) and ozonation to improve the secondary effluent quality of Isfahan North wastewater treatment plant. Therefore, the filtered effluent by a pretreatment unit from micro-screen drum filter type with a pore size of 20 µm entered the disinfection pilots containing medium pressure (MP) UV lamps and ozonation system as tertiary treatment. In this study, the irradiation dose of UV (430–3,680 mW/cm2), and injection dose (10–40 mg/L), and contact time (1–15 min) of ozonation were altered. The results showed that the total suspended solids were reduced by 61.27% at the maximum... 

    Effect of the ozonation pretreatment on biogas production from waste activated sludge of tehran wastewater treatment plant

    , Article Biomass and Bioenergy ; Volume 152 , 2021 ; 09619534 (ISSN) Hodaei, M ; Ghasemi, S ; Khosravi, A ; Vossoughi, M ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    In this study, the ozonation impact on anaerobic digestion of wasted thickened activated sludge of Tehran wastewater treatment plant has been investigated. Regarding that, the thickened activated sludge, a final solid waste of treatment plants, was subjected to ozonation pretreatment to evaluate its characteristics. Three major sludge characteristics were considered for investigating ozonation effects on anaerobic digestion. A comparison of two different ozone doses, i.e., 0.05 and 0.1 gO3 g−1TS was performed for short-term (10 days) and long-term (30 days) sludge retention times. Furthermore, biogas production, sludge composition, dewaterability, and energy balancing, were studied during... 

    Enhancement of PMS activation in an UV/ozone process for cyanide degradation: a comprehensive study

    , Article Pigment and Resin Technology ; Volume 49, Issue 5 , August , 2020 , Pages 409-414 ; ISSN: 03699420 Goodarzvand Chegini, Z ; Hassani, H ; Torabian, A ; Borghei, S. M ; Sharif University of Technology
    Emerald Group Publishing Ltd  2020
    Abstract
    Purpose: This paper aims to study peroxymonosulfate (PMS) activation in the ultraviolet (UV)/ozone process for toxic cyanide degradation from aqueous solution by a novel and simple method. Design/methodology/approach: Photocatalytic degradation of cyanide (CN-) was carried out using a bench-scale photoreactor. Optimization of the UV/ozone process for the highest removal of cyanide was obtained. The effect of parameters such as ozone concentration, PMS concentration, temperature, cations (Cu2+, Co2+ and Fe2+), cyanide concentration, anions (bicarbonate, carbonate, chloride, nitrite, nitrate and sulfate [SO42−]) and scavengers (ethanol [EtOH], humic acid, TBA and NaN3) was investigated for CN-... 

    Comparing the efficacy of catalytic ozonation and photocatalytical degradation of cyanide in industrial wastewater using ACF-TiO2: catalyst characterisation, degradation kinetics, and degradation mechanism

    , Article International Journal of Environmental Analytical Chemistry ; 18 May , 2020 Goodarzvand Chegini, Z ; Hassani, A. H ; Torabian, A ; Borghei, S. M ; Sharif University of Technology
    Taylor and Francis Ltd  2020
    Abstract
    In the present study, the ACF-TiO2 catalyst was synthesised and used as a catalyst for the destruction of toxic cyanide in both synthetic and real industrial wastewaters. The ACF-TiO2 catalyst was found to be micro-porous with the BET surface area of 163 m2/g. The effect of different operational parameters such as catalyst concentration, cyanide concentration, operation time, and ozone concentration were target parameters in the present study. The findings show that 500 mg/L of catalyst is the optimum value for the photocatalytical process to completely oxidise 25 mg/L of cyanide within 10 min. While it was found that 300 mg/L of catalyst in the presence of 200 mg/h ozone is enough to remove... 

    Comparing the efficacy of catalytic ozonation and photocatalytical degradation of cyanide in industrial wastewater using ACF-TiO2: catalyst characterisation, degradation kinetics, and degradation mechanism

    , Article International Journal of Environmental Analytical Chemistry ; Volume 102, Issue 13 , 2022 , Pages 3023-3042 ; 03067319 (ISSN) Goodarzvand Chegini, Z ; Hassani, A. H ; Torabian, A ; Borghei, S. M ; Sharif University of Technology
    Taylor and Francis Ltd  2022
    Abstract
    In the present study, the ACF-TiO2 catalyst was synthesised and used as a catalyst for the destruction of toxic cyanide in both synthetic and real industrial wastewaters. The ACF-TiO2 catalyst was found to be micro-porous with the BET surface area of 163 m2/g. The effect of different operational parameters such as catalyst concentration, cyanide concentration, operation time, and ozone concentration were target parameters in the present study. The findings show that 500 mg/L of catalyst is the optimum value for the photocatalytical process to completely oxidise 25 mg/L of cyanide within 10 min. While it was found that 300 mg/L of catalyst in the presence of 200 mg/h ozone is enough to remove... 

    Contribution of the Middle Eastern dust source areas to PM10 levels in urban receptors: Case study of Tehran, Iran

    , Article Atmospheric Environment ; Volume 75 , 2013 , Pages 287-295 ; 13522310 (ISSN) Givehchi, R ; Arhami, M ; Tajrishy, M ; Sharif University of Technology
    2013
    Abstract
    The origins and evolution of the Middle Eastern dust storms which frequently impact the residents of this arid region were studied. A methodology was adapted and developed to identify the desert regions of potential dust sources and determine their contributions to PM10 concentrations in the highly-populated receptor city of Tehran, Iran. Initially, the episodes of regional dust intrusion and the resulting amounts of increase in the particulate concentrations during these episodes were determined using a statistical analyzing methodology. The dust episodes were also inspected with the aerosol index information from the Ozone Monitoring Instrument (OMI). The Hybrid Single-Particle Lagrangian...