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The effect of influent COD and upward flow velocity on the behaviour of sulphate-reducing bacteria
, Article Process Biochemistry ; Volume 40, Issue 7 , 2005 , Pages 2305-2310 ; 13595113 (ISSN) ; Ghavipanjeh, F ; Mirjafari, P ; Sharif University of Technology
2005
Abstract
The effect of up velocity and influent COD concentration on the activity of sulphate-reducing bacteria (SRB) in UASB reactors is discussed. To study these effects, four UASB reactors were built and utilized in parallel. Examinations were carried out in two different concentrations of molasses (500 mg COD/l and 1000 mg COD/l) and four different upward flow velocities. It was observed that at velocities greater than 1 m/h, SRB bacteria were easily washed out from the reactors due to lower density and lack of ability to form dense and firm granules. It was found that in low-strength wastewaters with a COD to sulphate ratio of 2, an upward velocity in the range of 1.5-2.5 m/h could be...
Experimental Study the Treatment of Oily Wastewater by Thermophilic External Membrane Bioreactor(MBR)
, M.Sc. Thesis Sharif University of Technology ; Kariminia, Hamidreza (Supervisor) ; Vosoughi, Manouchehr (Supervisor) ; Hesampour, Mehrdad (Co-Advisor)
Abstract
The membrane bioreactor (MBR) as an alternative method for simultaneous biodegradation and separation of oily water has received more attention, recently. Normally the MBR works at ambient temperature; therefore, the yield of biodegradation recalcitrant components is low. Increasing temperature improves the efficiency of degradation and reduces the amount of produced sludge. In this study the performance of an aerobic thermophilic and mesophilic membrane bioreactor (MBR) for treating oily wastewater has been investigated. In batch conditions (without applying the membrane), a comparison between COD removal in mesophilic and thermophilic conditions was done. In thermophilic conditions COD and...
Performance Evaluation of Membrane Bioreactors in Treating Municipal Wastewater
, M.Sc. Thesis Sharif University of Technology ; Torkian, Ayoub (Supervisor)
Abstract
Membrane bioreactors can replace the activated sludge process and the final clarification step in municipal wastewater treatment. The combination of bioreactor and crossflow microfiltration allows for a high chemical oxygen demand (COD) reduction of synthetic wastewater. In this study, experimental data from a laboratory scale membrane bioreactor are presented. In order to investigate the influence of various operating parameters such as hydraulic retention time (HRT), biomass concentration and organic loading rate on organic pollutant removal, the pilot scale submerged membrane bioreactor (SMBR) with a Polyvinylidene Fluoride (PVDF) hollow fiber membrane module was conducted using synthetic...
Study of the MBR System for the Removal of Ethyl Benzene and Styrene from Petrochemical Wastewater and Process Optimization by Reducing Membrane Fouling
, Ph.D. Dissertation Sharif University of Technology ; Shayegan, Jalaloddin (Supervisor)
Abstract
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...
Optimizing OLR and HRT in a UASB reactor for pretreating high- Strength municipal wastewater
, Article Chemical Engineering Transactions ; Volume 24 , 2011 , Pages 1285-1290 ; 19749791 (ISSN) ; Shayegan, J ; Sharif University of Technology
Abstract
This study was carried out for examination of a lab-scale UASB reactor for optimization of organic loading rate and hydraulic retention time. The total volume of the reactor was 5 1 with an effective height of 160 cm and diameter of 5 cm. This reactor was used to treat fortified municipal wastewater at volumetric organic loadings of 3.6, 7.2, 10.8, and 14.4 kg m3 d 1 at temperature 30°C. The result of present work indicated an optimum range for organic loading (7.2 to 10.8 kg m-3 d-1) with COD removal efficiency of about 85%. Moreover, optimum HRT for influent COD concentration of 1200mg/l is shown to be only 4 hours. Furthermore nitrate removal efficiency was about 80% at optimized organic...
Application of moving bed biofilm reactor in the removal of pharmaceutical compounds (diclofenac and ibuprofen)
, Article Journal of Environmental Chemical Engineering ; Volume 6, Issue 4 , 2018 , Pages 5530-5535 ; 22133437 (ISSN) ; Borghei, S. M ; Ekhlasi Nia, A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Pharmaceutical waste has attracted significant attention in the past two decades due to the current high consumption of pharmaceuticals together with the development of reliable detection technologies. In order to acquire better understanding on pharmaceuticals removal in biological processes, the treatment of synthetic wastewater containing diclofenac (DFN) and ibuprofen (IBU), two of the most commonly prescribed medicines worldwide, was studied using a moving bed biofilm reactor (MBBR). An 8.5-L aerobic MBBR with Kaldnes packing filling ratio of 40% was designed. The controlled parameters were pH within neutral range, temperature of 37 °C, mixed liquor suspended solids (MLSS) of 2100 mg/L,...
Investigation of Petroleum Pollutant Removal in a Membrane Bioreactor
, M.Sc. Thesis Sharif University of Technology ; Kariminia, Hamid Reza (Supervisor) ; Moslehi Moslehabadi, Parivash (Supervisor)
Abstract
In this study, the performance of Convectional activated sludge reactor (CAS), moving bed biofilm reactor (MBBR) and coupled MBBR-membrane bioreactor (MBR) for diesel removal was investigated.
Hydrocarbon quantification was conducted based on a photometery method at 250 nm after extraction with n-hexane.
Experiments with MBBR was conducted in a batch mode using the sludge obtained from a municipal wastewater treatment plant. In order to adapt microorganisms with diesel as carbon sourse, diesel concentration was gradualy increased from 100 to 3400 ppm where diesel removal efficiency decreased from 62/1 to 26/6 %. However, after addition of diesel degrading bacteria (previously...
Hydrocarbon quantification was conducted based on a photometery method at 250 nm after extraction with n-hexane.
Experiments with MBBR was conducted in a batch mode using the sludge obtained from a municipal wastewater treatment plant. In order to adapt microorganisms with diesel as carbon sourse, diesel concentration was gradualy increased from 100 to 3400 ppm where diesel removal efficiency decreased from 62/1 to 26/6 %. However, after addition of diesel degrading bacteria (previously...
Formaldehyde biodegradation using an immobilized bed aerobic bioreactor with pumice stone as a support
, Article Scientia Iranica ; Volume 18, Issue 6 , December , 2011 , Pages 1372-1376 ; 10263098 (ISSN) ; Borghei, M ; Sharif University of Technology
Abstract
The objective of this study is the investigation of formaldehyde degradation in a bioreactor with pumice stone as a support. The reactor was tested at different synthetic wastewater concentrations with total COD of 500, 1000 and 1500 mgL, respectively, at 24 h hydraulic retention time. The effect of feed composition was tested by changing the COD TCOD FA ratio in order to analyze the impact of formaldehyde concentration. The average formaldehyde and COD removal efficiencies obtained in the reactor were 97.1% and 88%, respectively. The maximum COD and formaldehyde removal efficiencies occurred at the COD TCOD F of 41 at COD T=1000mgL. The effect of toxic shock on reactor performance was...
Anaerobic digestion of vegetable waste
, Article Chemical Engineering Transactions ; Volume 24 , 2011 , Pages 1291-1296 ; 19749791 (ISSN) ; Shayegan, J ; Sharif University of Technology
Italian Association of Chemical Engineering - AIDIC
2011
Abstract
Fruit and vegetable wastes are produced in large quantities in Iran, and constitute a source of nuisance in municipal landfills. The objective of this study was to optimize the applications of anaerobic digestion for the treatment of municipal organic wastes. We studied the effect of organic loading rates on anaerobic digestion of vegetable wastes. The complete-mix, pilot-scale digester with working volume of 70 1 was used. The experiments were conducted at 34°C with a fixed hydraulic retention time of 25 days. The digester was operated at different organic feeding rates of 1.4, 2 and 2.75 kg VS/(m3.d). The biogas produced had methane composition of 49.7- 64% and biogas production rates of...
An investigation on using MDCs for an efficient desalination process as pretreatment of reverse osmosis
, Article Journal of Water Supply: Research and Technology - AQUA ; Volume 69, Issue 4 , 1 June , 2020 , Pages 322-331 ; Abbaspour, M ; Javid, A. H ; Hassani, A. H ; Sharif University of Technology
IWA Publishing
2020
Abstract
Microbial desalination cell (MDC) is a new bio-electrochemical technique which converts chemical energy into electrical energy, and at the same time desalinates water and treats wastewater. In this study, MDC performance and water biofouling conditions were tested as an efficient pretreatment desalination process of reverse osmosis (RO). The experiments were designed in a three-chamber reactor to compare the performance of batch and continuous fed modes, using bio-cathode and synthetic wastewater in four different hydraulic retention times and 17 and 35 g/L NaCl concentrations. According to the results, maximum salt removal of about 52.3% was obtained in the continuously fed MDC at 35 g/L...
Sulphate reduction in a three-stage packed-bed anaerobic bioreactor
, Article World Environmental and Water Resources Congress 2008: Ahupua'a, Honolulu, HI, 12 May 2008 through 16 May 2008 ; Volume 316 , 2008 ; 9780784409763 (ISBN) ; Poorhashem, Q ; Environmental and Water Resources Institute of ASCE ; Sharif University of Technology
2008
Abstract
In this paper the effect of the sulphate concentration on the performance of a three-stage anaerobic baffled packed-bed reactor (ABPR) was investigated. Synthetic wastewater (3000 mg COD/l) was used as the sole organic substrate. The 30 liters fixed-bed bioreactor filled with plastic packing and divided in three equal sections was used as the mABPR reactor. The unit was run at a hydraulic retention time (HRT) of 1 day and at temperature of 25° C. The results of this study showed that when COD/SO42- ratios were changed from 30 to 3 with increasing sulphate concentration from 100 to 1000 mg/l, COD removal slightly was decreased. Maximum COD and sulphate removal were 91 and 96%, respectively,...
Optimising nutrient removal of a hybrid five-stage Bardenpho and moving bed biofilm reactor process using response surface methodology
, Article Journal of Environmental Chemical Engineering ; Volume 7, Issue 1 , 2019 ; 22133437 (ISSN) ; Mehrabani Zeinabad, A ; Borghei, S. M ; Torresi, E ; Muñoz Sierra, J ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Nutrient pollution has become a global environmental issue. Innovative biological nutrient removal (BNR) processes are needed to overcome the drawbacks of conventional technologies. This study evaluates the potential of a hybrid 5-stage Bardenpho - moving bed biofilm reactor (MBBR) process for organic carbon and nutrient removal from municipal wastewater at different hydraulic retention time (HRT) and nitrate recycle ratio (R). Response surface methodology (RSM) based on a central composite design (CCD) of thirteen experiments was applied to optimize the nitrogen and phosphorus conversion of the treatment system. High removal efficiencies of about 98.20%, 92.54%, 94.70% and 96.50% for total...
Meta-analysis of bioenergy recovery and anaerobic digestion in integrated systems of anaerobic digestion and microbial electrolysis cell
, Article Biochemical Engineering Journal ; Volume 178 , 2022 ; 1369703X (ISSN) ; Arvin, A ; Feizi, A ; Dehdashti, B ; Torkian, A ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In current study, a meta-analysis approach was used to identify and evaluate the impact of various factors on the performance of integrated systems of anaerobic digestion with microbial electrolysis cell. In this study, related articles on the topic were systematically identified and collected according to the considered criteria, and the effect size that refers to the value of the difference between variables mean (total chemical oxygen demand (TCOD) removal rate and CH4 yield) was estimated. According to the meta-analysis, fed-batch operation mode, the range of 20< temperature ≤30 °C, metal cathodes, the range of 500< anode surface area ≤5000 cm2, HRT (hydraulic retention time) >20 days,...
The highest inhibition coefficient of phenol biodegradation using an acclimated mixed culture
, Article Water Science and Technology ; Volume 73, Issue 5 , 2016 , Pages 1033-1040 ; 02731223 (ISSN) ; Sharifi Abdar, P. S ; Borghei, S. M ; Sharif University of Technology
IWA Publishing
2016
Abstract
In this study a membrane biological reactor (MBR) was operated at 25±1 °C and pH = 7.5±0.5 to treat synthetic wastewater containing high phenol concentrations. Removal efficiencies of phenol and chemical oxygen demand (COD)were evaluated at four various hydraulic retention times (HRTs) of 24, 12, 8, and 4 hours. The removal rate of phenol (5.51 kg-Phenol kg-VSS-1 d-1), observed at HRT of 4 h,was the highest phenol degradation rate in the literature.According toCODtests, therewere no significant organic matter in the effluent, and phenol was degraded completely by mixed culture. Substrate inhibition was calculated from experimental growth parameters using the Haldane, Yano, and Edward...
Techno-economic optimization of biogas-fueled micro gas turbine cogeneration systems in sewage treatment plant
, Article Energy Conversion and Management ; Volume 218 , 15 August , 2020 ; Avami, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The aim of this paper is to investigate the feasibility of a combined cooling, heating, and power generation system with a micro turbine using biogas as the fuel to supply the heat and electricity demands in a real wastewater treatment plant. The plant is optimized using the system's total cost rate and the amount of the produced biogas as objective functions. The anaerobic digester is modeled using the ADM1 model. The optimization variables include digester hydraulic retention time, compressor pressure ratio, isentropic compressor efficiency, recuperator pinch time temperature, turbine isentropic efficiency, turbine input temperature, and the number of micro turbines. In the first scenario...
Comparison of two mathematical models for correlating the organic matter removal efficiency with hydraulic retention time in a hybrid anaerobic baffled reactor treating molasses
, Article Bioprocess and Biosystems Engineering ; Volume 35, Issue 3 , 2012 , Pages 389-397 ; 16157591 (ISSN) ; Martín, A ; Borja, R ; Martin, M. A ; Hedayat, N ; Sharif University of Technology
Abstract
A modelling of the anaerobic digestion process of molasses was conducted in a 70-L multistage anaerobic biofilm reactor or hybrid anaerobic baffled reactor with six compartments at an operating temperature of 26 °C. Five hydraulic retention times (6, 16, 24, 72 and 120 h) were studied at a constant influent COD concentration of 10,000 mg/L. Two different kinetic models (one was based on a dispersion model with first-order kinetics for substrate consumption and the other based on a modification of the Young equation) were evaluated and compared to predict the organic matter removal efficiency or fractional conversion. The first-order kinetic constant obtained with the dispersion model was...
Simultaneous biological organic matter and nutrient removal in an anaerobic/anoxic/oxic (A2O) moving bed biofilm reactor (MBBR) integrated system
, Article International Journal of Environmental Science and Technology ; Volume 14, Issue 2 , 2017 , Pages 291-304 ; 17351472 (ISSN) ; Seyedsalehi, M ; Safari, G. H ; Ebrahimi Arjestan, M ; Barzanouni, H ; Ghadimi, S ; Kamani, H ; Haratipour, P ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2017
Abstract
In the present study, the performance of three moving bed biofilm reactors (MBBRs) has been evaluated in series with anaerobic/anoxic/oxic (A2O) units for simultaneous removal of organic matter and nutrients (nitrogen and phosphorous) from a synthetic wastewater with characteristics similar to those of a typical municipal wastewater. Response surface methodology based on central composite design was used to investigate the effects of nitrate recycle ratio, hydraulic retention time (HRT), and influent chemical oxygen demand (COD) on the organic and nutrient removal and optimization process. The optimized values of influent COD, HRT, and R were 462 mg/L, 10 h, and 3.52, respectively. The...
Biological removal of nutrients (N & P) from urban wastewater with a modified integrated fixed-film activated sludge-oxic settling anoxic system using an anoxic sludge holding tank
, Article Water and Environment Journal ; Volume 35, Issue 2 , 2021 , Pages 830-846 ; 17476585 (ISSN) ; Takdastan, A ; Borghei, S. M ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
In this research, the efficiency of the integrated fixed-film activated sludge-oxic settling anoxic (IFAS-OSA) system in biological nutrient removal was studied. The oxic-settling anoxic (OSA) process is known as a cost effective way to reduce the nutrients (nitrogen and Phosphorus). According to the results, the percentages of total nitrogen removal efficiency in the IFAS, IFAS-OSA2h and IFAS-OSA4h systems were 78.56 ± 2.46, 83.60 ± 0.92 and 85.03 ± 1.69, respectively, while the percentages of phosphorus removal efficiency in these systems were 32.69 ± 8.25, 36.35 ± 6.73 and 39.87 ± 3.61, respectively. The PCR-RFLP method showed that C. albicans had the greatest prevalence (n = 36, 90%)....