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    Biodegradation of aromatic hydrocarbons in a compost biofilter

    , Article Journal of Chemical Technology and Biotechnology ; Volume 78, Issue 7 , 2003 , Pages 795-801 ; 02682575 (ISSN) Torkian, A ; Dehghanzadeh, R ; Hakimjavadi, M ; Sharif University of Technology
    Two laboratory-scale biofilters filled with the same type of packing material were operated at different gas flow rates and influent concentrations of toluene and xylene in order to investigate their performance in treating waste gas streams. The columns contained a mixture of municipal compost as a base material and wood chips as a bulking agent in an 80:20 ratio; the porosity was 54%. Microbial acclimation was achieved by addition of nutrient-enriched solution along with pollutants for a week by daily mixing and natural aeration. During the start-up of the systems with inlet concentrations of 20 and 70 ppm for toluene and xylene, respectively, high biomass growth resulted in pressure drops... 

    BTEX Removal from Aqueous Alkanolamines by Adsorption Method with Active Carbon

    , M.Sc. Thesis Sharif University of Technology Hassanzadeh, Nadia (Author) ; Safe Kordi, Ali Akbar (Supervisor) ; Taghi Zoghi, Ali (Supervisor)
    Natural gas contains small amount of benzene, toluene, ethyl benzene and meta-xylene (BTEX). These compounds are soluble in amine solutions and accumulate in aqueous amine solution during sour gas removal process. They produce problems such as foaming in amine adsorption columns. The aim of this work is to study BTEX removal from aqueous amine solution by means of activated carbon. Three different commercially available granular activated carbons were used in experiments. Experiments were divided in static and dynamic adsorption categories. In the static tests, equilibrium adsorption of all three activated carbons were performed and the most effective activated carbon sample determined by... 

    Solid-phase Microextraction of BTEXs by Sol-Gel-Based Trimethoxy Silyl Propyl Methacrylate Fiber

    , M.Sc. Thesis Sharif University of Technology Soltannezhad dizaji, Mahda (Author) ; Bagheri, Habib (Supervisor)
    Conventional solid phase microextraction fibers posses relatively low recommended operating temperature, instability and swelling in organic solvents, breakage of the fiber, stripping of coatings, and bending of the needle. Some of these problems have been obviated by covalent bonding of the polymer phase to the fused-silica substrate by sol-gel technology, but the easy breakage of the fiber still is a remaining challenge In this work, after successful fabrication of unbreakable SPME fibers based on 3-(trimethoxysilyl)propyl methacrylate precursor deposited on the surface of copper wire, the same approach was carried out to synthesis new sol-gel based SPME fibers. Three different coated... 

    Numerical Simulation of Non-Aqueous and Dissolved Petroleum Hydrocarbon Transport in Groundwater

    , M.Sc. Thesis Sharif University of Technology MahmoodiNobar, Farzad (Author) ; Ataie Ashtiani, Behzad (Supervisor)
    Within the past few years, soil and groundwater resources contamination by petroleum-based products has become of great concern in the environmental engineering literature as a serious environmental problem throughout the world. Amongst petroleum hydrocarbons, groundwater contamination by Non-Aqueous Phase Liquids (NAPLs) is one of the most important environmental problems. In order to effectively remediate contaminated sites, knowledge of the distribution of the NAPLs is essential. The success of the remedial design will be dependent on the ability to predict the subsurface distribution of the NAPLs. Release of these compounds from spills and leaky underground storage tanks into subsurface... 

    A Superhydrophobic Melamine Formaldehyde Sorbent for Micro Extraction of Pollutants from Aquatic Media

    , M.Sc. Thesis Sharif University of Technology Zeinali, Shakiba (Author) ; Bagheri, Habib (Supervisor)
    In this project, melamine formaldehyde was chosen as initial substrate for its high porosity. Then for having superhydrophobic surface, surface functional groups were silanized and deactivated as a result. It was assumed that high porosity of prepared sorbent and its nonpolar nature, can increase extraction efficiency. To study extraction efficiency of the prepared sorbent, it was filled inside a needle and used for needle-trap head-space extraction of BTEX (abbreviation for Benzene, Toluene, Ethylbenzene and Xylenes). Needle packed with sorbent was held on headspace of sample containing BTEX and head- space was pumped with a peristaltic pump. Pumping introduces fresh sample to sorbent... 

    Emission Estimation for Volatile Organic Compounds (VOCs) form Evaporation Ponds in the Upstream Oil and Gas Industry

    , M.Sc. Thesis Sharif University of Technology Hadivi, Pouya (Author) ; Arhami, Mohammad (Supervisor)
    This study aims to estimate the emission rate of Volatile Organic Components (VOCs) and hazardous air pollutants from the surface of evaporation ponds in oil and gas upstream industries. With respect to the irrecoverable consequences of such emissions, the emission of air pollutants in the oil and gas upstream industries are alarming. Hence, estimation of the pollutants’ emission and surface pollution monitoring are needed for controlling and decreasing of air pollutants in oil and gas upstream industries and also presenting and performing suitable and efficient solutions. The studied ponds in this research include 4 ponds in the oil and gas upstream industries which have been used for... 

    Evaluation of Vermifilter Efficiency in Petroleum Wastewater Treatment (BTEX)

    , M.Sc. Thesis Sharif University of Technology Kanani, Matin (Author) ; Torkian, Ayub (Supervisor) ; Mirzai, Mohammad (Supervisor)
    The aim of this thesis was to find the optimum retention time for treatment of synthetic petroleum wastewater by a wastewater treatment system made with a bucket, mineral material and earthworms residing in a vermibed. In order to make the desired flow happen, height difference was utilized. The polluting substance used for making wastewater was BTEX. As the wastewater was synthetic, the concentration was also a variable. The ultimate soluble concentration was 3200 mg/l and more concentrations were not tested. Parameters such as number of worms, worm’s growth rate and their distribution pattern, humidity amount and distribution and worm’s acclimatization time during organic loading shock... 

    Treatment of oilfield produced water by dissolved air precipitation/solvent sublation

    , Article Journal of Petroleum Science and Engineering ; Volume 80, Issue 1 , 2011 , Pages 26-31 ; 09204105 (ISSN) Bayati, F ; Shayegan, J ; Noorjahan, A ; Sharif University of Technology
    Dissolved air precipitation/solvent sublation (DAP/SS) was used for treatment of simulated and real oilfield produced water to generate very fine bubbles which are necessary for effective separation. In this method micro bubbles produced by saturation of air in a pressurized packed column were released in an atmospheric column leading the bubbles to raise resulting trapped contaminants in the Gibbs layer around them to be removed by a layer of immiscible solvent at the top of column. The method was conducted to solutions including Benzene, Toluene and Chlorobenzene (ClB) as part of BTEX contaminants in produced water, mixture of them as simulated produced water and real oilfield produced... 

    Experimental and theoretical study on BTEX removal from aqueous solution of diethanolamine using activated carbon adsorption

    , Article Journal of Natural Gas Science and Engineering ; Volume 22 , 2015 , Pages 618-624 ; 18755100 (ISSN) Aleghafouri, A ; Hasanzadeh, N ; Mahdyarfar, M ; SeifKordi, A ; Mahdavi, S. M ; Zoghi, A. T ; Sharif University of Technology
    Elsevier  2015
    Activated carbon beds are extensively used in sweetening units of natural gas refineries for the purification of contaminated amine solutions. Correlation of experimental adsorption data using an analytical isotherm equation is need to design an accurate activated carbon bed. In the present study, the adsorption of BTEX from Diethanolamine (DEA) solution by commercial and granular activated carbon (AC) were performed. The Langmuir, Freundlich and Sips isotherm models were used to describe the equilibrium data. The accuracy of the results obtained from the adsorption isotherm models was compared and the values for the regressed parameters were reported. The results show that the Freundlich... 

    Biopolymeric based Interpenetrating Polymer Network for Extending the Microextraction Techniques

    , M.Sc. Thesis Sharif University of Technology Veisi, Nazila (Author) ; Bagheri, Habib (Supervisor)
    In this study, gelatin/polyvinylpyrrolidone semi interpenetrating polymer network scaffold was synthesized in presence of glutaraldehyde as a cross linker and a porous structure was obtained by freeze drying method. The biocompatible network with properties like huge porosity, good thermal stability and establishing different interactions, was employed as an extractive phase in needle trap device and used for evaluation of benzene, toluene, ethylbenzene and xylene (BTEX) in conjugation with gas chromatography-flame ionization detector. For investigating semi interpenetrating polymer network efficiency, Different ratios of gelatin and polyvinylpyrrolidone (gelatin/polyvinylpyrrolidone: 1:0,... 

    Resorcinol-Formaldehyde Xerogel for Analysis of Environmental Pollutant in Aqueous Sample

    , M.Sc. Thesis Sharif University of Technology Zare, Maryam (Author) ; Bagheri, Habib (Supervisor) ; Es-haghi, Ali (Supervisor)
    In this study, a new resorcinol-formaldehyde xerogel was synthesized based on sol-gel technology and employed as a sorbent for micro solid phase extraction (µ-SPE) of BTEX and some selected pesticides from aqueous samples.
    In the first part, a µ-SPE method in combined with headspace solvent microextraction (HS-SME) along with gas chromatography- mass spectrometry detection (GC–MS) was developed for the analysis of BTEX in aqueous samples. In our knowledge, this is for the first time that these two different extraction methods has been coupled to maximize the advantage of each extraction method. Influential parameters such as the peristaltic pump flow rate, extraction volume, extraction... 

    Adsorption of petroleum monoaromatics from aqueous solutions using granulated surface modified natural nanozeolites: Systematic study of equilibrium isotherms

    , Article Water, Air, and Soil Pollution ; Volume 217, Issue 1-4 , 2011 , Pages 611-625 ; 00496979 (ISSN) Seifi, L ; Torabian, A ; Kazemian, H ; Bidhendi, G. N ; Azimi, A. A ; Charkhi, A ; Sharif University of Technology
    Petroleum monoaromatics including benzene, toluene, ethylbenzene, and xylenes (BTEX) are among the notorious volatile organic compounds that contaminate water and soil. In this study, a surfactant- modified natural zeolite and its relevant granulated nanozeolites were evaluated as potential adsorbents for removal of petroleum monoaromatics from aqueous solutions. All experiments performed in batch mode at constant temperature of 20°C and pH of 6.8 for 48 h. The results revealed that the amount of BTEX uptake on granulated zeolites nanoparticles were remarkably higher than the parent micron size natural zeolite (in the order of four times). The isotherms data were analyzed using five models... 

    Roles of inorganic oxide nanoparticles on extraction efficiency of electrospun polyethylene terephthalate nanocomposite as an unbreakable fiber coating

    , Article Journal of Chromatography A ; Volume 1375 , 2015 , Pages 8-16 ; 00219673 (ISSN) Bagheri, H ; Roostaie, A ; Sharif University of Technology
    Elsevier  2015
    In the present work, the roles of inorganic oxide nanoparticles on the extraction efficiency of polyethylene terephthalate-based nanocomposites were extensively studied. Four fiber coatings based on polyethylene terephthalate nanocomposites containing different types of nanoparticles along with a pristine polyethylene terephthalate polymer were conveniently electrospun on stainless steel wires. The applicability of new fiber coatings were examined by headspace-solid phase microextraction of some environmentally important volatile organic compound such as benzene, toluene, ethylbenzene and xylene (BTEX), as model compounds, from aqueous samples. Subsequently, the extracted analytes were... 

    A single–step synthesized supehydrophobic melamine formaldehyde foam for trace determination of volatile organic pollutants

    , Article Journal of Chromatography A ; Volume 1525 , 2017 , Pages 10-16 ; 00219673 (ISSN) Bagheri, H ; Zeinali, S ; Baktash, M. Y ; Sharif University of Technology
    Superhydrophobic materials have attracted many attentions in recent years while their application in sample preparation remained almost intact. In this project, a rough surface of melamine formaldehyde foam was silanized by chemical deposition of trichloromethylsilane to form a highly porous and superhydrophobic material, presumably a suitable medium for extracting non–polar compounds such as benzene and its methyl derivatives. The prepared sorbent was packed in a needle for the headspace needle–trap microextraction of benzene, toluene, ethylbenzene and xylenes (BTEX). Major parameters associated with the extraction/desorption processes were considered for optimization. Under the optimized... 

    Land use regression models for Alkylbenzenes in a middle eastern megacity: Tehran study of exposure prediction for environmental health research (tehran sepehr)

    , Article Environmental Science and Technology ; Volume 51, Issue 15 , 2017 , Pages 8481-8490 ; 0013936X (ISSN) Amini, H ; Schindler, C ; Hosseini, V ; Yunesian, M ; Künzli, N ; Sharif University of Technology
    American Chemical Society  2017
    Land use regression (LUR) has not been applied thus far to ambient alkylbenzenes in highly polluted megacities. We advanced LUR models for benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene (BTEX), and total BTEX using measurement based estimates of annual means at 179 sites in Tehran megacity, Iran. Overall, 520 predictors were evaluated, such as The Weather Research and Forecasting Model meteorology predictions, emission inventory, and several new others. The final models with R2 values ranging from 0.64 for p-xylene to 0.70 for benzene were mainly driven by traffic-related variables but the proximity to sewage treatment plants was present in all models indicating a major local... 

    Degradation of BTEX in groundwater by nano-CaO2 particles activated with L-cysteine chelated Fe(III): enhancing or inhibiting hydroxyl radical generation

    , Article Water Supply ; Volume 21, Issue 8 , 2021 , Pages 4429-4441 ; 16069749 (ISSN) Sun, X ; Ali, M ; Cui, C ; Lyu, S ; Sharif University of Technology
    IWA Publishing  2021
    The simultaneous oxidation performance of benzene, toluene, ethylbenzene, and xylene (BTEX) by nanoscale calcium peroxide particles (nCaO2) activated with ferric ions (Fe(III)) and the mechanism of the enhancement of BTEX degradation by L-cysteine (L-cys) were investigated. The batch experimental results showed that the nCaO2/Fe(III)/L-cys process was effective in the destruction of BTEX in both ultrapure water and actual groundwater. A proper amount of L-cys could enhance BTEX degradation due to the promotion of Fe(II)/Fe(III) redox cycles by the participation of L-cys, but an excessive presence of L-cys would cause inhibition. Adding 1.0 mM L-cys to the nCaO2/Fe(III) system, the... 

    Spatiotemporal description of BTEX volatile organic compounds in a middle eastern megacity: tehran study of exposure prediction for environmental health research (Tehran SEPEHR)

    , Article Environmental Pollution ; Volume 226 , 2017 , Pages 219-229 ; 02697491 (ISSN) Amini, H ; Hosseini, V ; Schindler, C ; Hassankhany, H ; Yunesian, M ; Henderson, S. B ; Künzli, N ; Sharif University of Technology
    The spatiotemporal variability of ambient volatile organic compounds (VOCs) in Tehran, Iran, is not well understood. Here we present the design, methods, and results of the Tehran Study of Exposure Prediction for Environmental Health Research (Tehran SEPEHR) on ambient concentrations of benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene (BTEX), and total BTEX. To date, this is the largest study of its kind in a low- and middle-income country and one of the largest globally. We measured BTEX concentrations at five reference sites and 174 distributed sites identified by a cluster analytic method. Samples were taken over 25 consecutive 2-weeks at five reference sites (to be used for... 

    A systematic review of land use regression models for volatile organic compounds

    , Article Atmospheric Environment ; Volume 171 , 2017 , Pages 1-16 ; 13522310 (ISSN) Amini, H ; Yunesian, M ; Hosseini, V ; Schindler, C ; Henderson, S. B ; Künzli, N ; Sharif University of Technology
    Various aspects of land use regression (LUR) models for volatile organic compounds (VOCs) were systematically reviewed. Sixteen studies were identified published between 2002 and 2017. Of these, six were conducted in Canada, five in the USA, two in Spain, and one each in Germany, Italy, and Iran. They were developed for 14 different individual VOCs or groupings: benzene; toluene; ethylbenzene; m-xylene; p-xylene; (m/p)-xylene; o-xylene; total BTEX; 1,3-butadiene; formaldehyde; n-hexane; total hydro carbons; styrene; and acrolein. The models were based on measurements ranging from 22 sites in El Paso (USA) to 179 sites in Tehran (Iran). Only four studies in Rome (Italy), Sabadell (Spain),...