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    A Monte Carlo simulation of nutrient diffusion and reaction in immobilized cell systems

    , Article Chemical Physics ; Volume 321, Issue 1-2 , 2006 , Pages 34-40 ; 03010104 (ISSN) Yari, B ; Khorasheh, F ; Kheirolomoom, A ; Sharif University of Technology
    In this study a Monte Carlo simulation was used to investigate the effect of cell reactivities and particle diffusivities in the cells and matrix on the diffusion and reaction rate constants in gel-immobilized cell systems with different spatial cell configurations. A variety of conditions were examined ranging from instantaneous to very slow reactions with reaction probabilities equal to or less than one, and diffusivity ratios bigger or smaller than one in a spherical domain. In the case of high reactivity (diffusion-limited), the simulation results indicated a decrease in the reaction rate constants when heterogeneity in the cell distribution was increased. In the case of low reactivity... 

    An optimized procedure to develop a 3-dimensional microfluidic hydrogel with parallel transport networks

    , Article International Journal for Numerical Methods in Biomedical Engineering ; 2018 ; 20407939 (ISSN) Jafarkhani, M ; Salehi, Z ; Shokrgozar, M. A ; Mashayekhan, S ; Sharif University of Technology
    Wiley-Blackwell  2018
    The development of microfluidic hydrogels is an attractive method to generate continuous perfusion, induce vascularization, increase solute delivery, and ultimately improve cell viability. However, the transport processes in many in vitro studies still have not been realized completely. To address this problem, we have developed a microchanneled hydrogel with different collagen type I concentrations of 1, 2, and 3 wt% and assessed its physical properties and obtained diffusion coefficient of nutrient within the hydrogel. It is well known that microchannel geometry has critical role in maintaining stable perfusion rate. Therefore, in this study, a computational modeling was applied to... 

    Response of bacillus cereus on Zea mays under different doses of zinc sulphate

    , Article Acta Botanica Croatica ; Volume 80, Issue 2 , 2021 , Pages 191-198 ; 03650588 (ISSN) Shahzad, A ; Qin, M ; Nazir, M ; Shakoor, A ; Billah, M ; Zaib, G ; Sharif University of Technology
    Department of Biology, Faculty of Science, University of Zagreb  2021
    Anthropogenic activities have added a large amount of heavy metals to the environment. Heavy metal contaminants affect the physiological and biological properties of soil and plant health. Zinc (Zn) is an essential micronutrient and it promotes plant growth and development but a higher concentration of the metal causes reduction in plant growth. The present study was aimed to evaluate the response of Bacillus cereus on maize plants at different concentrations of ZnSO4 (20, 40 and 60 mg kg–1) amended in the soil under pot experiment conditions. The experiment was conducted by using complete randomized design (CRD) with three replications. Higher doses of ZnSO4 inhibited maize growth and... 

    Municipal wastewater treatment and fouling in microalgal-activated sludge membrane bioreactor: Cultivation in raw and treated wastewater

    , Article Journal of Water Process Engineering ; Volume 49 , 2022 ; 22147144 (ISSN) Najafi Chaleshtori, S ; Shamskilani, M ; Babaei, A ; Behrang, M ; Sharif University of Technology
    Elsevier Ltd  2022
    Since the advent of conventional activated sludge biological treatment plants, their low efficiency in nitrogen and phosphorus removal has become a significant concern. Therefore, in this study, the performance of microalgal-activated sludge membrane bioreactor (MAS-MBR) as a self-biological treatment or as a post-treatment for conventional biological treatments was investigated. A continuous MAS-MBR with two ratios of algae/sludge (only microalgae and 5:1) was used to treat raw and treated wastewater. The optimum case was achieved with the cultivation of mixed algae/sludge in raw wastewater (R2 case). In this case, the ammonium and phosphorus removal efficiencies were 94.36 ± 3.5 and 88.37... 

    Effect of culture age and initial inoculum size on lipid accumulation and productivity in a hybrid cultivation system of Chlorella vulgaris

    , Article Process Safety and Environmental Protection ; Volume 104 , 2016 , Pages 111-122 ; 09575820 (ISSN) Heidari, M ; Kariminia, H. R ; Shayegan, J ; Sharif University of Technology
    Institution of Chemical Engineers 
    Chlorella vulgaris was cultivated in a hybrid (two-stage) system. The effect of the transferring time from nutrient-replete phase with a low light intensity (photobioreactor) to the nutrient deprivation phase (open pond) with a higher light intensity, as well as the effect of initial cell concentration in the deprivation phase, on the growth rate and lipid content of the microalgae was investigated. The microalgae were transferred to the nutrient deprived medium at different intervals with various initial cell concentrations. Transferring the cultivated medium of the 4th day with the initial cell concentration of 66 mg L−1 into the deprivation phase resulted in a highest lipid productivity... 

    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) Naderi, H ; Javid, A. H ; Borghei, S. M ; Eslamizadeh, M ; Sharif University of Technology
    Desalination Publications  2022
    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... 

    Microalgae Cultivation for Simultaneous Treatment of Municipal Wastewater and Biofuel Feedstock Production

    , M.Sc. Thesis Sharif University of Technology Ebrahimian Kafshaei, Atefeh (Author) ; Vossoughi, Manoochehr (Supervisor) ; Kariminia, Hamid Reza (Supervisor)
    Depletion of fossil fuels and their price increase, world is going to face critical energy challenges in the near future. Thereforefinding proper replacements for fossil fuels is inevitable. On the other hand, releasing of huge amount of wastewater into environment imposes serious nvironmental threats. Microalgae can be a potential alternative for biological wastewater treatment as well as fuel production. Microalgae grown in wastewater can eliminate remaining nitrogen and phosphorous. The gorwn biomass can be used for biofuel production afterward. Microalgae can also decrease the amount of greenhouse gas through the consumption of CO2 as energy sources. In this study, nutrient removal from... 

    Seasonal pollutant removal by Lactuca sativa, Medicago sativa and Phragmites australis in constructed wetlands

    , Article Applied Ecology and Environmental Research ; Volume 15, Issue 4 , 2017 , Pages 67-76 ; 15891623 (ISSN) Aminsharei, F ; Borghei, S. M ; Arjomandi, R ; Nouri, J ; Pendashteh, A ; Sharif University of Technology
    Corvinus University of Budapest  2017
    The main objective of this study was to compare the removal efficiency of nutrients using Lactuca sativa, Medicago sativa and Phragmites australis in subsurface flow constructed wetlands with horizontal flow. In order to test water quality, fabricated reactors designed and the plants cultivated in the soil while their root were inside the wastewater. A long time study carried out from spring till end of autumn (9 months) in order to evaluate the difference in removal rate based on the seasonal changes. The highest removal rate was during summer which followed by spring and autumn. Thus, the effect of plants on the removal efficiency of organic matter (COD, BOD), TSS and nutrient (P and TN)... 

    Investigation of intestinal enzyme activity and effects of non-starch polysaccharide on it

    , Article International Journal of Engineering and Technology(UAE) ; Volume 7, Issue 4 , 2018 , Pages 28-31 ; 2227524X (ISSN) Piryaei, M ; Motamedi, A ; Mehrabi Far, A ; Sharif University of Technology
    Science Publishing Corporation Inc  2018
    This experiment investigates the effects of utilizing Rahnama cultivar with high non-starchy polysaccharide content and supplementation of xylanase enzyme in poultry feed on the productivity features, nutrient digestibility and intestinal enzymes activity of 21-47 week laying hens. The experiment was conducted quite randomly and in factorial design that included eight treatments with 4 wheat levels (zero, 23, 46 and 69% that contained 1.8, 2.0, 2.2, 2.4% of xylose respectively) and two level enzymes (with and without enzyme) and 5 replications (6 hens) in each replication. During the experiment, by xylose level increase in diet, the weight (p > 0.05) and mass of the egg (p > 0.01) decreased... 

    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) Ashrafi, E ; Mehrabani Zeinabad, A ; Borghei, S. M ; Torresi, E ; Muñoz Sierra, J ; Sharif University of Technology
    Elsevier Ltd  2019
    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... 

    Evaluation of nutrient removal and biomass production through mixotrophic, heterotrophic, and photoautotrophic cultivation of chlorella in nitrate and ammonium wastewater

    , Article International Journal of Environmental Research ; Volume 12, Issue 2 , 2018 , Pages 167-178 ; 17356865 (ISSN) Babaei, A ; Mehrnia, M. R ; Shayegan, J ; Sarrafzadeh, M. H ; Amini, E ; Sharif University of Technology
    Springer International Publishing  2018
    In this study, the effect of mixotrophic, heterotrophic, photoautotrophic (CO2 of air source), and photoautotrophic (bicarbonate source) cultivation of Chlorella vulgaris was investigated on microalgae growth rate and nutrient removal under different kinds of nitrogen sources. The highest N–NH3 +, N–NO3 −, P–PO4 3− (in ammonium source), and P–PO4 3− (in nitrate source) removal efficiency (87.28 ± 0.89, 70.00 ± 1.20, 87.00 ± 3.10, and 78.10 ± 1.95%, respectively) was reached in the mixotrophic culture. In all cultivations, when nitrate was used as the nitrogen source, specific growth rate, biomass productivity, and specific oxygen production rate (SOPR) were higher than the one with ammonium... 

    Control of Eutrophication in Anzali Wetland by Artificial Floating Islands

    , M.Sc. Thesis Sharif University of Technology Shahrouz Ebrahimi, Pouneh (Author) ; Abrishamchi, Ahmad (Supervisor)
    Anzali wetland, in the Caspian Sea, northern Iranian province of Gilan, ranges from fresh near the tributary streams to brackish near the mouth into the harbor and the sea. Anzali wetland has faced with the serious levels of eutrophication because on the other hand, the lagoon has decreased in size during current century, to less than a quarter of its former extent and on the other hand, this wetland is faced with entering a huge amount of nutrient elements due to human activities in its watershed. Discharge of industrial wastewater, animal wastes, timber harvesting and the most important entering, rice farms irrigated wastewater are of the considerable causes of eutrophication in wetland.... 

    Appropriate Methods of River Quality Restoration

    , M.Sc. Thesis Sharif University of Technology Ikani, Nima (Author) ; Hashemian, Jamal (Supervisor)
    The practice of river restoration has grown exponentially over the last several decades. There has been little empirical evaluation of whether restoration projects individually or cumulatively achieve the legally mandated goals of improving the structure and function of rivers. Nutrient reduction through simple methods is the most critical factor. The simplest method, which has minimal financial burden as well as preventing, and reducing the entrance of pollutants into the Chalus River (Mazandaran, in north of Iran), has been selected. The origins of rivers start at a high point and move with a steep. ... 

    Comparison of different trophic cultivations in microalgal membrane bioreactor containing N-riched wastewater for simultaneous nutrient removal and biomass production

    , Article Process Biochemistry ; Volume 51, Issue 10 , 2016 , Pages 1568-1575 ; 13595113 (ISSN) Babaei, A ; Mehrnia, M. R ; Shayegan, J ; Sarrafzadeh, M. H ; Sharif University of Technology
    Elsevier Ltd  2016
    In this study, a submerged membrane was installed in a bioreactor to treat N-riched wastewater and obtain high biomass productivity. Chlorella vulgaris was cultivated under mixotrophic, heterotrophic, and photoautotrophic conditions in different kinds of nitrogen sources (nitrate and ammonium) to compare the microalgae growth and nutrient removal in a membrane bioreactor. Further, the respirometric and photosynthetic activities of microalgae were investigated to evaluate the viability of microalgae in different conditions. The highest biomass productivity was obtained under mixotrophic cultivation in ammonium source (0.230 ± 0.009 gr/L d). Moreover, with this type of cultivation and nitrogen... 

    Fertilizer, landscape features and climate regulate phosphorus retention and river export in diverse Midwestern watersheds

    , Article Biogeochemistry ; Volume 146, Issue 3 , 2019 , Pages 293-309 ; 01682563 (ISSN) Boardman, E ; Danesh Yazdi, M ; Foufoula Georgiou, E ; Dolph, C. L ; Finlay, J. C ; Sharif University of Technology
    Springer  2019
    Non-point source pollution of phosphorus (P) is a primary cause of eutrophication of aquatic ecosystems, and poses a persistent management challenge due to the dynamic and poorly understood processes controlling the transport and transformation of P at the watershed scale. We examined phosphorus inputs, retention, and riverine losses in 62 diverse watersheds that included a wide range of land cover and use (minimally disturbed to human dominated) and human P inputs in Minnesota, USA. Fertilizer inputs from row crop cultivation were the dominant source of P to agricultural watersheds. A large majority of P inputs was retained in watershed soils or removed in agricultural products. However,... 

    Investigating sensitivity of flow parameters and uncertainty analysis of nutrient transport and dispersion model in shallow water. (Case study: Peer-bazar river and anzali wetland)

    , Article Desalination and Water Treatment ; Volume 174 , 2020 , Pages 204-214 Homami, M ; Mirbagheri, S. A ; Borghei, S. M ; Abbaspour, M ; Sharif University of Technology
    Desalination Publications  2020
    Accurate modeling of runoff in watersheds requires calibration and uncertainty analysis of effective flow parameters and identifying of their statistical characteristics based on inter-parameter relationships and model inputs. In this research, the transport and diffusion of pollution (nutrients) in the river were simulated through the two-dimensional finite-volume method using the shallow water equations. To numerically solve these equations, the governing equations were converted into linear equations. Uncertainty and sensitivity of the prepared pollution model were analyzed to achieve better results in estimating pollution concentrations in rivers within a reliable range. In this study,... 

    Phosphorus transport in intensively managed watersheds

    , Article Water Resources Research ; Volume 55, Issue 11 , 2019 , Pages 9148-9172 ; 00431397 (ISSN) Dolph, C. L ; Boardman, E ; Danesh Yazdi, M ; Finlay, J. C ; Hansen, A. T ; Baker, A. C ; Dalzell, B ; Sharif University of Technology]
    Blackwell Publishing Ltd  2019
    Understanding controls of P movement through watersheds are essential for improved landscape management in intensively managed regions. Here, we analyze observational data from 104 gaged river sites and 176 nongaged river sites within agriculturally dominated watersheds of Minnesota, USA, to understand the role of landscape features, land use practices, climate variability, and biogeochemical processes in total, dissolved and particulate P dynamics at daily to annual scales. Our analyses demonstrate that factors mediating P concentration-discharge relationships varied greatly across watersheds and included near-channel sediment sources, lake and wetland interception, assimilation by algal P,... 

    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) Jaafari, J ; 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
    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) Fazelipour, M ; Takdastan, A ; Borghei, S. M ; Sharif University of Technology
    John Wiley and Sons Inc  2021
    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%).... 

    Investigation of Nutrient Removal in BNR Systems Based on Bardenpho Process

    , M.Sc. Thesis Sharif University of Technology Banayan Esfahani, Ehsan (Author) ; Borghei, Mehdi (Supervisor)
    Large amounts of Nitrogen and Phosphorous in municipal and industrial wastewater result in Eutrophication and many diseases in human. Nowadays, various methods have been used to remove Nitrogen and Phosphorous from wastewater. Besides Physical and Chemical methods, Biological approaches are utilized based on Biological Nutrient Removal (BNR) Systems. One of the most important and practical processes of these systems is Modified Bardenpho, which contain 5 stages and used for Nitrogen and Phosphorous Removal with high efficiency. In this thesis, we used Modified Bardenpho Process for removing nutrients. This method has 5 Moving Bed Biofilm Reactor (MBBR) which are respectively, anaerobic...