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microalga
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Light harvesting and photocurrent generation by nanostructured photoelectrodes sensitized with a photosynthetic pigment: A new application for microalgae
, Article Bioresource Technology ; Volume 163 , July , 2014 , Pages 1-5 ; ISSN: 09608524 ; Janfaza, S ; Abbaspour Aghdam, F ; Sharif University of Technology
Abstract
Here in this study, successful conversion of visible light into electricity has been achieved through utilizing microalgal pigments as a sensitizer of nanostructured photo-electrode of dye-sensitized solar cells (DSSCs). For the first time, photosynthetic pigments extracted from microalgae grown in wastewater is employed to imitate photosynthesis process in bio-molecule-sensitized solar cells. Two designs of photoanode were employed: 10μm nanoparticular TiO2 electrode and 20μm long self-ordered, vertically oriented nanotube arrays of titanium dioxide films. Microalgal photosynthetic pigments are loaded on nanostructured electrodes and their photovoltaic performances have been investigated....
Lipid production in mixotrophic cultivation of Chlorella vulgaris in a mixture of primary and secondary municipal wastewater
, Article Renewable Energy ; Vol. 71 , November , 2014 , pp. 502-508 ; ISSN: 09601481 ; Kariminia, H. R ; Vosoughi, M ; Sharif University of Technology
Abstract
Microalgae's biomass productivity and oil content depend heavily on the method of its cultivation. In this study, nutrient removal from municipal wastewater by Chlorella vulgaris in batch culture was investigated. Carbon dioxide was supplied from sodium hydrogen carbonate. Effect of parameters including light intensity, sodium hydrogen carbonate concentration, and daily illumination time on the productivity of biomass and lipid was investigated. Lipid and biomass production of C.vulgaris increased at higher concentration of sodium hydrogen carbonate concentration and higher light intensity until a certain value and then decreased, but longer daily illumination time, increased both biomass...
Choosing a Suitable Microalgae for Bioremediation of Heavy Metals Regarding Iran's Clamate
, M.Sc. Thesis Sharif University of Technology ; Yaghmaei, Soheyla (Supervisor)
Abstract
The pollution of water resources with heavy metals as a result of industrial activities threatens the lives of all living organisms. Therefore, separation of heavy metals from wastewater before entering our invironment is very important. Various chemical and physical methods such as absorption, chemical precipitation, extraction by solvent and ion exchange can be used to separate heavy metals but each of these methods have their own problems such as imperfect separation of heavy metals, need for expensive facilities and refining systems, high energy consumption and leaving pollutant residuals that need to be separated. On the other hand, the methods mentioned above can not separate heavy...
The role of co-solvents in improving the direct transesterification of wet microalgal biomass under supercritical condition
, Article Bioresource Technology ; Volume 193 , October , 2015 , Pages 90-96 ; 09608524 (ISSN) ; Vossoughi, M ; Pazuki, G ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
In this research, direct conversion of wet algal biomass into biodiesel using supercritical methanol was studied. In this process, microalgal lipids simultaneously was extracted and converted to biodiesel under high pressure and temperature conditions without using any catalyst. Several experiments have been performed to optimize the methanol amount and it has been revealed that the best performance was achieved by using methanol/wet biomass ratio of 8:1. The effect of using various co-solvents in increasing the efficiency of the supercritical process was investigated. It has been shown that hexane was the most effective co-solvent and its optimal ratio respect to wet biomass was 6:1. The...
Effect of various carbon sources on biomass and lipid production of Chlorella vulgaris during nutrient sufficient and nitrogen starvation conditions
, Article Bioresource Technology ; Volume 180 , 2015 , Pages 311-317 ; 09608524 (ISSN) ; Malekzadeh, M ; Jalilian, F ; Vossoughi, M ; Pazuki, G ; Sharif University of Technology
Abstract
In this research, a two-stage process consisting of cultivation in nutrient rich and nitrogen starvation conditions was employed to enhance lipid production in Chlorella vulgaris algal biomass. The effect of supplying different organic and inorganic carbon sources on cultivation behavior was investigated. During nutrient sufficient condition (stage I), the highest biomass productivity of 0.158. ±. 0.011. g/L/d was achieved by using sodium bicarbonate followed by 0.130. ±. 0.013, 0.111. ±. 0.005 and 0.098. ±. 0.003. g/L/d for sodium acetate, carbon dioxide and molasses, respectively. Cultivation under nitrogen starvation process (stage II) indicated that the lipid and fatty acid content...
Experimental Studies on Recovery Process of Microalgae using Electric Current and Membrane
, M.Sc. Thesis Sharif University of Technology ; Vosughi, Manoochehr (Supervisor) ; Moslemi, Mohammad Reza (Supervisor)
Abstract
Microalgae is a major problem in water resources due to its adverse influence on water treatment process and water quality like color, odor and taste. In addition microalgae removal is an important process in food and pharmacy industry. Electrocoagulation is a potential method for microalgae removal. Another method for microalgae recovery is membrane treatment. This study is focusing on using both methods separately and simultaneously. To achieve this, the removal of Chlorella Vulgaris, a fresh water microalgae, was used in experiments. In first phase the experiments were solely on electrocoagulation and the effect of several parameters including current density, electrocoagulation duration,...
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) ; Kariminia, H. R ; Shayegan, J ; Sharif University of Technology
Institution of Chemical Engineers
Abstract
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...
Experimental study and thermodynamic modeling for determining the effect of non-polar solvent (hexane)/polar solvent (methanol) ratio and moisture content on the lipid extraction efficiency from Chlorella vulgaris
, Article Bioresource Technology ; Volume 201 , 2016 , Pages 304-311 ; 09608524 (ISSN) ; Abedini Najafabadi, H ; Hakim, M ; Feilizadeh, M ; Vossoughi, M ; Rashtchian, D ; Sharif University of Technology
Elsevier Ltd
Abstract
In this research, organic solvent composed of hexane and methanol was used for lipid extraction from dry and wet biomass of Chlorella vulgaris. The results indicated that lipid and fatty acid extraction yield was decreased by increasing the moisture content of biomass. However, the maximum extraction efficiency was attained by applying equivolume mixture of hexane and methanol for both dry and wet biomass. Thermodynamic modeling was employed to estimate the effect of hexane/methanol ratio and moisture content on fatty acid extraction yield. Hansen solubility parameter was used in adjusting the interaction parameters of the model, which led to decrease the number of tuning parameters from 6...
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) ; Mehrnia, M. R ; Shayegan, J ; Sarrafzadeh, M. H ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
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...
Electricity generation, desalination and microalgae cultivation in a biocathode-microbial desalination cell
, Article Journal of Environmental Chemical Engineering ; Volume 5, Issue 1 , 2017 , Pages 843-848 ; 22133437 (ISSN) ; Kariminia, H. R ; Vosoughi, M ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
Recently, microalgae has received a high attention for application in bioelectrochemical systems due to its potential to be used for oxygen generation and biodiesel production. In this study performance of algal biocathode in a microbial desalination cell (MDC) was evaluated against air cathode and biocathode microbial fuel cell (MFC). Effluent of a dairy wastewater treatment plant with COD of 1000 mg l-1 was utilized as substrate in the anode and the microalgae Chlorella vulgaris was inoculated in the cathode using a synthetic culture media. Experiments were conducted using two different saline water concentrations including 15 g l-1 (MDC-1) and 35 g l-1 (MDC-2) in a desalination cell and...
Biodiesel production from Spirulina microalgae feedstock using direct transesterification near supercritical methanol condition
, Article Bioresource Technology ; Volume 239 , 2017 , Pages 378-386 ; 09608524 (ISSN) ; Karimi Sabet, J ; Ghotbi, C ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
Microalgae as a candidate for production of biodiesel, possesses a hard cell wall that prevents intracellular lipids leaving out from the cells. Direct or in situ supercritical transesterification has the potential for destruction of microalgae hard cell wall and conversion of extracted lipids to biodiesel that consequently reduces the total energy consumption. Response surface methodology combined with central composite design was applied to investigate process parameters including: Temperature, Time, Methanol-to-dry algae, Hexane-to-dry algae, and Moisture content. Thirty-two experiments were designed and performed in a batch reactor, and biodiesel efficiency between 0.44% and 99.32% was...
The effect of different light intensities and light/dark regimes on the performance of photosynthetic microalgae microbial fuel cell
, Article Bioresource Technology ; Volume 261 , 2018 , Pages 350-360 ; 09608524 (ISSN) ; Roshandel, R ; Yaghmaei, S ; Mardanpour, M. M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
This study develops a photosynthetic microalgae microbial fuel cell (PMMFC) engaged Chlorella vulgaris microalgae to investigate effect of light intensities and illumination regimes on simultaneous production of bioelectricity, biomass and wastewater treatment. The performance of the system under different light intensity (3500, 5000, 7000 and 10,000 lx) and light/dark regimes (24/00, 12/12, 16/8 h) was investigated. The optimum light intensity and light/dark regimes for achieving maximum yield of PMMFC were obtained. The maximum power density of 126 mW m−3, the coulombic efficiency of 78% and COD removal of 5.47% were achieved. The maximum biomass concentration of 4 g l−1 (or biomass yield...
Inhibitory effects of functionalized indium doped ZnO nanoparticles on algal growth for preservation of adobe mud and earthen-made artworks under humid conditions
, Article International Biodeterioration and Biodegradation ; Volume 127 , Febraury , 2018 , Pages 209-216 ; 09648305 (ISSN) ; Mallakin, A ; Malekmohammady, F ; Khosravi Nejad, F ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this article, indium doped ZnO nanoparticles (alloy nanoparticles) were investigated as inhibitors against algae growth on adobe mud and earthen artworks for surface preservation from destruction caused by micro-organisms under humid conditions, through surface modification and activation run off. Nanoparticles (NPs) were fabricated by physical vapor deposition (PVD) growth mechanism. The fabricated NPs were approximately 20 nm in size. The Chlorella vulgaris and Scenedesmus quadricauda were tested by application of indium doped ZnO nanoparticles (In/ZnO NPs) as inhibitors. As concentrations of NPs increased, the negative impacts of NPs on the algal growth were enhanced and physical...
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) ; Mehrnia, M. R ; Shayegan, J ; Sarrafzadeh, M. H ; Amini, E ; Sharif University of Technology
Springer International Publishing
2018
Abstract
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...
Municipal Wastewater Treatment Using Microalgal-Sludge System
, M.Sc. Thesis Sharif University of Technology ; Shaygan Salek, Jalaloddin (Supervisor) ; Mehrnia, Mohammad Reza (Supervisor)
Abstract
If wastewater is not properly treated, then the environment and human health can be negatively impacted. These impacts can include harm to fish and wildlife populations, oxygen depletion and contamination of drinking water. In the typical wastewater treatment process, the goal of primary, secondary and tertiary effluent treatment is to reduce or remove organic matter, solids, nutrients, disease-causing organisms and other pollutants from the treated wastewater before it is discharged to a body of water. Biological methods for wastewater treatment are much preferable for being more economical and environmentally friendly. Biological treatment of wastewater using algal-bacterial culture...
Experimental and Theoretical Study of the Lipid Extraction from Wet Microalgae for Biodiesel Production
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davood (Supervisor) ; Vossoughi, Manoochehr (Supervisor)
Abstract
In this study, different stages of biodiesel production from microalgae were investigated, specifically the extraction step.Various cultivation methods were also studied among which cultivation under stress was the best. Different carbon sources were also investigated to achieve highest growth. Sodium acetate with complete growth was achieved after 8 days with 6.22% fatty acid recovery. Different mixtures of solvents were compared with Blye and Dier method. Results showed that the mixture of hexane and methanol with crude lipid extraction of 15% and fatty acid recovery of 3.97% were chosen as the solvent mixture of equilibria experiments.Organic solvent composed of hexane (non-polar...
Experimental Studies and Optimization of Microalgae Cultivation in a Photo-Bioreactor for Bio-Diesel Production
, M.Sc. Thesis Sharif University of Technology ; Vossoghi, Manouchehr (Supervisor) ; Alemzadeh, Iran (Supervisor)Optimization of carbohydrate productivity of Spirulina microalgae as a potential feedstock for bioethanol production
, Article International Journal of Environmental Science and Technology ; Volume 16, Issue 3 , 2019 , Pages 1303-1318 ; 17351472 (ISSN) ; Baghdadi, M ; Torang, A ; Sarkhosh, S ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2019
Abstract
The main goal of this research is to use the biomass productivity, carbohydrate content, and carbohydrate productivity as useful responses for optimization of macronutrients concentrations (K2HPO4, NaHCO3, and NaNO3) in cultivation of Spirulina microalgae as a feedstock for bioethanol production. In this study, individual and synergistic effects of medium components on the mentioned responses were investigated. The culture medium was optimized using central composite design for achieving the maximize biomass productivity (165 mg L−1 day−1 at K2HPO4: 438 mg L−1, NaHCO3: 15.92 g L−1, and NaNO3: 0.5 g L−1), carbohydrate content (42.0% of dry mass at K2HPO4: 192 mg L−1, NaHCO3: 5.71 g L−1, and...
Experimental Study and Process Design of Oil Extraction from Microalgae Chlorella Vulgaris to Produce Biodiesel
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fathollah (Supervisor) ; Vossoughi, Manoochehr (Supervisor)
Abstract
The experimental investigation of biodiesel production stages from microalgae especially lipid extraction stage was conducted in this thesis. The optimal rate of biomass productivity and optimal method in lipid extraction for biodiesel production was determined.
A photobioreactor was designed and constructed to cultivate microalgae C. Vulgaris according to researchers’ works and obtained results in this study. The process parameters were examined and the optimal parameters were obtained according to the necessary tests which were carried out. Then, several methods of lipid extraction using different solvents such as chloroform, methanol, and n-hexane were investigated and the best...
A photobioreactor was designed and constructed to cultivate microalgae C. Vulgaris according to researchers’ works and obtained results in this study. The process parameters were examined and the optimal parameters were obtained according to the necessary tests which were carried out. Then, several methods of lipid extraction using different solvents such as chloroform, methanol, and n-hexane were investigated and the best...
Experimental and Theoretical Study of the Transesterification Products Extraction in Biodiesel Production
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Manoochehr (Supervisor) ; Rashtchian, Davood (Supervisor)
Abstract
The experimental investigation of biodiesel production stages from microalgae especially biomass production stage was conducted in this thesis. The optimal rate of biomass productivity was determined.
A photobioreactor was designed and constructed to cultivate microalgae C. Vulgaris according to researchers’ works and obtained results in this study. The process parameters were examined and the optimal parameters were obtained according to the necessary tests which were carried out.
According to the results, the optimal condition for growing of microalgae was obtained with aeration of 6 lit/min with 3% CO2, and CO2 injection regime of 45 sec. injection and 3 min. of stoppage. A rapid...
A photobioreactor was designed and constructed to cultivate microalgae C. Vulgaris according to researchers’ works and obtained results in this study. The process parameters were examined and the optimal parameters were obtained according to the necessary tests which were carried out.
According to the results, the optimal condition for growing of microalgae was obtained with aeration of 6 lit/min with 3% CO2, and CO2 injection regime of 45 sec. injection and 3 min. of stoppage. A rapid...