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aeration
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Comparison of ozonation and aeration methods in removal of naphthalene from aqueous solution
, Article Asian Journal of Chemistry ; Volume 25, Issue 16 , 2013 , Pages 9135-9137 ; 09707077 (ISSN) ; Borghei, S. M ; Hassani, A. H ; Mirbagheri, S. A ; Javid, A. H ; Sharif University of Technology
2013
Abstract
High molecular mass of naphthalene make it non-biodegradable and the biological methods for treated the pollutant are much time consuming. In this paper, two methods of ozonation and aeration are used to remove naphthalene. Because of the industrial wastewater has a great range of pH, in this study different concentrations of soluble naphthalene are placed in variable pH conditions, different contact times and changes in amount of aeration and ozonation. ANOVA results indicated a significant difference between two methods. The average removal of naphthalene by use of ozonation is 55 % and 37 % for aeration. As results, the best conditions that naphthalene are removed is in acidic environment...
Studies on treatment of carbonaceous wastewater by Fixed Film Aeration Tank
, Article Scientia Iranica ; Volume 9, Issue 1 , 2002 , Pages 47-52 ; 10263098 (ISSN) ; Sharif University of Technology
Sharif University of Technology
2002
Abstract
In this paper, a modified activated sludge process using a Fixed Film Aeration Tank (FFAT) was investigated as an improvement for the usual activated sludge or trickling filtration processes. The aeration tank of the system was arranged with fixed parallel saran nets, which were set vertically as supporting media for microbial growth. A carbonaceous solution was brought into contact with microorganisms in the media and was oxidized aerobically. Filamentous microorganisms predominantly grew on the films and the COD removal increased with the increase in accumulated biomass in the system. Simulation of treatment performance in the system was carried out using mathematical models. The...
Simultaneous ammonium and nitrate removal by a modified intermittently aerated sequencing batch reactor (SBR) with multiple filling events
, Article Polish Journal of Chemical Technology ; Volume 18, Issue 3 , 2016 , Pages 72-80 ; 15098117 (ISSN) ; Borghei, S. M ; Hassani, A. H ; Takdastan, A ; Sharif University of Technology
De Gruyter Open Ltd
Abstract
Optimized methods for simultaneous removal of nitrate, nitrite and ammonium are important features of nutrient removal. Nitrogen removal efficiency in an intermittently aerated sequencing batch reactor (IA-SBR) with multiple filling events was studied. No external carbon source was added and three filling events were considered. Oxidationreduction potential (ORP) and pH curve at solids retention time (SRT) of 20 d were analyzed. Effects of three organic loading rates (OLR), 0.67, 1.0 and 1.5 kgCOD/m3d, and three nitrogen loading rates (NLR), 0.054, 0.1 and 0.15 kgN/m3d, on nitrogen removal were studied. Nitrate Apex in pH curve and Nitrate Knee in ORP profile indicated that the end of...
Mechanistic evaluation of cationic dyes adsorption onto low-cost calcinated aerated autoclaved concrete wastes
, Article International Journal of Environmental Science and Technology ; 2021 ; 17351472 (ISSN) ; Eftekhari, M ; Tabrizi, M. G ; Fathollahi Fard, A. M ; Tian, G ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Application of construction and demolition (C&D) wastes were considered as sustainable development goals (SDGs) for maintaining raw materials. Also, lightweight concretes such as aerated autoclaved concrete (AAC) were used for partitioning spaces in the building industry. Moreover, the waste products of the mentioned materials were increased due to the rise of old construction demolitions. This study contributes a calcinated aerated autoclaved concrete (CAAC) which is efficient, powerful, highly rapid, non-expensive and novel adsorbent for the removal of cationic dyes including malachite green (MG), methyl violet (MV) and methylene blue (MB) form water samples. The impacts of different...
The Effect of Zinc Salt in COD Removal in a SAF Bioreactor
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi (Supervisor)
Abstract
One of the most important parts of bacteria growth is specific concentration of nutrients added. Although the trace amount of heavy metals are required for bacteria growth, after a threshold concentration they may cause damage or kill the bacteria. Scientifically speaking, all these trace nutrients should be consider as a profitable source of energy for bacteria growth. There are several studies throughout pondering whether the advantages of using heavy metals, such as Zn, outweigh the drawbacks. It has been proven that heavy metals, especially, zinc salt, can improve microbial growth up to a specific threshold concentration. In this study, two upward submerged aerated reactors, which had 12...
Effect of Rheology on Producing Protease from Bacillus Subtilis through the Shake Flux into the Fermentor
, M.Sc. Thesis Sharif University of Technology ; Roostaazad, Reza (Supervisor)
Abstract
In this research, the optimization of culture medium and process conditions for the production of alkaline protease enzyme from Bacillus subtilis ATCC6633 strain for use in the detergent industry has been discussed. Among all the conditions affecting the growth and production of enzymes, the stirrer cycle in the fermenter, which causes different shear rates and is one of the most important factors in the amount of mixing and aeration, was chosen for further study. At first, the results obtained from the incubator shaker were carefully examined, and then different checks were made to adjust the fermenter stirrer speed through diagrams in three flow states: 1-laminar, 2-transitional, and...
Estimating Volatile Organic Compound emissions from wastewater circulating aeration tanks
, Article Scientia Iranica ; Volume 12, Issue 3 , 2005 , Pages 300-305 ; 10263098 (ISSN) ; Rashidkhani, A ; Sharif University of Technology
Sharif University of Technology
2005
Abstract
The need for the control of Volatile Organic Compounds (VOCs) has led engineers to modify wastewater aeration tank systems. In this research, air recirculation has been investigated as a possible VOC control strategy for these systems. A steady-state mathematical model of VOC emission rates has been developed from the fundamentals of VOC convection, volatilization and biodegradation. This model has been used to study the effect of aeration recirculation in enhancing the biodegradation of VOCs in the system, using dichloromethane as a typical VOC. A feasibility study considering plants of various sizes is needed to compare the costs and benefits of air recirculation to other VOC control...
Mechanistic evaluation of cationic dyes adsorption onto low-cost calcinated aerated autoclaved concrete wastes
, Article International Journal of Environmental Science and Technology ; Volume 19, Issue 7 , 2022 , Pages 6429-6444 ; 17351472 (ISSN) ; Eftekhari, M ; Tabrizi, M. G ; Fathollahi Fard, A. M ; Tian, G ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Application of construction and demolition (C&D) wastes were considered as sustainable development goals (SDGs) for maintaining raw materials. Also, lightweight concretes such as aerated autoclaved concrete (AAC) were used for partitioning spaces in the building industry. Moreover, the waste products of the mentioned materials were increased due to the rise of old construction demolitions. This study contributes a calcinated aerated autoclaved concrete (CAAC) which is efficient, powerful, highly rapid, non-expensive and novel adsorbent for the removal of cationic dyes including malachite green (MG), methyl violet (MV) and methylene blue (MB) form water samples. The impacts of different...
Optimization of Asparaginase Enzyme in Bioreactor
, M.Sc. Thesis Sharif University of Technology ; Vosoughi, Manouchehr (Supervisor) ; Alemzadeh, Iran (Supervisor)
Abstract
L-asparaginase enzyme is a well known enzyme due to itschemotherapeutic properties. However, this is not the only feature of the enzyme. L- asparaginase can be also used in food processing to reduce of acrylamide which is a carcinogenic substance. furthermore, acrylamide formation, is prevented by addition of the enzyme before cooking process of some foods such as chips, which contains sugar and asparagine amino acid. Due to use of the enzyme in food industry, we need to produce enzyme with high activity and cheaper raw material. In the present study, Candida utilis ATCC 9950 was used to produce asparaginase enzyme, and beet molasses and yeast extract was used as a carbohydrate and...
Enhancement of Alkaline Protease Production Using Process Factors
, M.Sc. Thesis Sharif University of Technology ; Roostaazad, Reza (Supervisor)
Abstract
In this research, we have studied optimization of culture medium and process factors for high alkaline protease production from Bacillus subtilis ATCC 6633 for detergent usage. Five parameter soy bean meal, initial pH, agitation rate, MgSO4, CaCl2 were selected for more studies. At first, one-factor-at-a-time method was applied to investigate effect of each factor separately. Then, optimum condition for maximum protease production was achieved using Minitab software Box-benhnken procedure. According to results, high protease production was seen in soy bean meal, 35 (g/L); MgSO4, 1 (g/L); CaCl2 , 1.5 (g/L); initial pH, 7; agitation rate, 150; inoculum ratio, 12% (v/v). The activity of the...
Enhancement of L-asparaginase production by candida utilis in a 13L fermenter and its purification
, Article International Journal of Engineering, Transactions B: Applications ; Volume 28, Issue 8 , 2015 , Pages 1133-1141 ; 1728-144X (ISSN) ; Alemzadeh, I ; Vosoughi, M ; Sharif University of Technology
Materials and Energy Research Center
2015
Abstract
L- asparaginase enzyme is a renown enzyme because of its chemotherapeutic properties. This enzyme may also be employed in food processing technology. The present study aimed, optimizing the agitation and aeration rate in L-asparaginase production, using C. utilis, ATCC 9950 in batch fermentation system. Beet molasses used as the carbohydrate source for enzyme production. A maximum asparaginase activity of 245.6 U/ml obtained after 20h of fermentation under optimal condition of 1.25 vvm aeration rate and 300 rpm agitation speed. Purification of the enzyme was also done by Acetone Precipitation and column chromatograph. Purified L-asparaginase revealed molecular weight 75 kDa and 82.7 % yield...
Investigation of short-time artificial aeration on water quality parameters and phytoplankton structure: a case study “Mamloo Reservoir”
, Article Desalination and Water Treatment ; Volume 254 , 2022 , Pages 217-228 ; 19443994 (ISSN) ; Javid, A. H ; Borghei, S. M ; Eslamizadeh, M ; Sharif University of Technology
Desalination Publications
2022
Abstract
Thermal stratification accompanied by a release of nutrients from sediment is a serious problem for the management of water quality. Water aeration and mixing technology can be widely used to control endogenous pollution and algae growth in reservoirs and lakes by water quality managers. In this research, a diffuser aeration system, was installed in a water column, in the Mamloo stratified Reservoir; and the impact of artificial aeration was brought under extensive assessment in relevance with the qualitative and biological parameters of the water, during the preliminary 6 d of aeration. The results showed that the thermal stratification was remarkably disturbed. After aeration, the amount...
CFD-DEM modeling of cuttings transport in underbalanced drilling considering aerated mud effects and downhole conditions
, Article Journal of Petroleum Science and Engineering ; Volume 160 , 2018 , Pages 229-246 ; 09204105 (ISSN) ; Rajabi, M ; Sharif University of Technology
Elsevier B.V
2018
Abstract
This paper presents a developed CFD (Computational fluid dynamics)-DEM (Discrete elements method) model to study the cuttings transportation in aerated mud drilling process for inclined annuli at downhole conditions. The model is conducted to determine the effects of liquid flow rate, air injection rate, annulus inclination angle, elevated temperature and pressure on the cuttings transport efficiency. The motion of the fluid is computed using CFD based approach with gas–liquid interface capturing provided by the volume-of-fluid (VOF) method. The dynamics of cutting phase is studied by DEM using soft sphere approach in order to take into account the particle collision phenomenon. The...
Improvement of Settleability and Sludge Characteristics in Moving Bed Biofilm Reactor (MBBR)
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mahdi (Supervisor)
Abstract
In the present study, effects of Post Aeration stage on moving bed biofilm reactor (MBBR) sludge and effluent quality was investigated by simulated wastewater. Reactors Volume were 3.2 and 5.9 Liter and their filling-fraction were 53% and 29%, respectively. All tests were done at 2.5 and 4.6 volume fraction, in which organic loading rates (OLR) were 2, 4, 6 g/L.d and Hydraulic retention times (HRT) were 3 and 6 hours. Increasing in HRT results in bioreactor efficiency improvement, the most efficiency values were found 81% and 84% for MBBR and MBBR-PA respectively at HRT of 6 hours and 53% filling-fraction. The greatest effect of post aeration on organic removal rate was obtained at HRT of 3...
Optimization of Aeration & Dissolved Oxygen Concentration in Moving Bed Bio Reactors
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi (Supervisor)
Abstract
In this research the performance of the Moving Bed Biofilm Rector (MBBR) in different amounts of dissolved oxygen (DO) was investigated. Reactor with a useful volume of 15 liters was used in this study. In order to obtain optimum oxygen concentration, stayed at 6, 10 and 15 hours, and at different levels of dissolved oxygen in the range 0.5 -6 mg/lit, the amount of organic material was removed respectively. Also, in two different aeration intensity of 3.5 and 5.5 liters per minute at different values of e% (percentage of filling of media) the mass transfer coefficient values were obtained. When the aeration intensity increases from 3.5 to 5.5 liters per minute, and the percentage of 40%...
Reclamation of Cooling Towers’ Blow Down In Order to Reuse Of Water
,
M.Sc. Thesis
Sharif University of Technology
;
Borghei, Mehdi
(Supervisor)
Abstract
In recent years,because of increasing problems that result from water shortage ,using of wastewater treated by high quality and entering them to water cycle is considered more than past.Large amount of waste waterare produced through cooling towers in industries per a day .Therefore ,cooling tower’s blow down is a most important source for reclamation and reuse of water .The purpose of this project was investigation ofefficiency of submerged aerated filter for treating low organic simulated blowdown water as a feed . The experimental unit consisted of 8/5 L filled with 70 percent of propylene media . After obtaining steady –state condition ,The SAF reactor was tested under...
Experimental Investigation of Liquid Jet Break-up In Cross Flow by Effervesvent Injector
,
M.Sc. Thesis
Sharif University of Technology
;
Morad, Mohammad Reza
(Supervisor)
Abstract
In This Study break up and trajectory of aerated liquid jet in subsonic cross flow has been investigated. An effervescent two phase flow injector has been used with two different diameters for its external orifice. The effects of non-dimensional parameters on the trajectory of aerated liquid jet were evaluated. Water was used as the fluid for the purpose of producing liquid jet. Air was used to produce gaseous phase in the injector and the cross flow as well.
A duct with a square cross section and a blower in the inlet of the duct were used to produce the cross flow. Mixture of air and water was injected into the cross flow by the injector installed at the bottom of the duct. Shadowgraph...
A duct with a square cross section and a blower in the inlet of the duct were used to produce the cross flow. Mixture of air and water was injected into the cross flow by the injector installed at the bottom of the duct. Shadowgraph...
Development of a Multi-functional Soil Column for Studying Bioremediation and Multiphase Flow
, M.Sc. Thesis Sharif University of Technology ; Sadeghi, Hamed (Supervisor)
Abstract
Soil and water pollution is one of the most common types of pollution in terrestrial and aquatic ecosystems. The development of mines and the oil and petrochemical industry on one hand and the non-compliance with environmental requirements on the other hand have caused large amounts of hydrocarbon pollutants and heavy metals to enter the environment in recent decades. Petroleum materials and heavy metals leak into the surrounding environment during drilling and extraction in oil sites and mines or during land and sea transportation, despite the measures taken to control their pollution. The conducted studies show that human industrial activities are the only cause of environmental pollution...
Physical Modeling of Bioremediation of Gasoline Spill in the Vadose Zone
, M.Sc. Thesis Sharif University of Technology ; Sadeghi, Hamed (Supervisor) ; Moghimi, Hamid (Co-Supervisor)
Abstract
Oil pollutants are among the important sources of pollution in countries with oil and gas industries such as Iran. Soil pollution by these pollutants is one of the environmental issues and hazards. All kinds of organic and inorganic pollutants in the soil may penetrate the underground water or enter the atmosphere in the form of gas, which respectively enters the food chain through absorption by plants or enter the body of living organisms through breathing. They include humans, which are a threat to the health and life of living beings. For example, many of these pollutions cause diseases such as cancer, suppression of the body's immune system, or even obesity; therefore, it is necessary to...
Effect of stitter speed and aeration rate on the production of glucose oxidase by Aspergillus niger
, Article Journal of Biological Sciences ; Volume 7, Issue 2 , 2007 , Pages 270-275 ; 17273048 (ISSN) ; Sarrafzadeh, M. H ; Alemzadeh, I ; Vosoughi, M ; Sharif University of Technology
Asian Network for Scientific Information
2007
Abstract
Dissolved oxygen tension and shear stress as two very important factors in fungal fermentation were studied in the batch cultures of Aspergillus niger. The intention was to maximize the total activity of glucose oxidase produced in a 5-1 bench-top bioreactor. 300 rpm found to be optimum for enzyme production, however in higher mixing rates higher growth was achieved. The maximum activity of glucose oxidase was obtained in 1.5 vvm while the best aeration rate for growth was 2 vvm. Glucose oxidase with the activity of 548 U mL-1 was produced in 1.5 vvm and 300 rpm as the optimum conditions. © 2007 Asian Network for Scientific Information