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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Particle Science & Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Forward Osmosis (FO),Nanocomposite Substrates,Graphene Oxide nanoplates,Internal Concentration Polarization (ICP)
- چکیده:
- چکیده انگلیسی: One of the limiting factors in good performance of forward osmosis (FO) membranes is the internal concentration polarization (ICP). To reduce ICP, thin film nanocomposite forward osmosis (TFN-FO) membranes were fabricated by adding different amounts of graphene oxide (GO) nanoplates (0-1 wt. %) to polymer matrix of polysulfone (PSf) substrate. The prepared nanocomposite membranes exhibited both hydrophilicity and porosity higher than that of neat PSf counterpart. An optimum amount of 0.5 wt% was obtained for GO addition into the membranes. The corresponding fabricated thin film nanocomposite (TFN) membrane (TFNG0.5) revealed a water permeability of 2.44 L/m2hbar which is 66% higher compared to an in-house made composite membrane. The FO performance of TFN was assessed by DI water as feed solution and 1 M NaCl as draw solution in AL-DS orientation. The water flux of the synthesized FO membranes increased upon adding of GO nanoplates and reached to a maximum water flux of 37.74 (L/m2h) for TFNG0.5 membrane. This flux is about 3 times higher than TFC membranes without significant changes in their salt rejection. The higher water flux of the TFN membranes can be attributed to ICP decrease originating from reduction of structural parameter of the membranes.
- انتشار مقاله: 23-05-1395
- نویسندگان: Saharnaz Tajik,Omid Moini Jazani,Soheila Shokrollahzadeh,Seyed Mahdi Latifi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Particle Science & Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: photocatalyst,photocatalytic reactor,Pollutants,Semiconductor,water and wastewater treatment
- چکیده:
- چکیده انگلیسی: During recent years, many advanced oxidation techniques have been investigated for water and wastewater treatment to overcome the shortage of clean water. This review summarizes the background and principles of photocatalysis applied as an advanced oxidation technology. In particular, this paper focuses on modification of photocatalysts with various dopants as well as the novel photocatalytic reactors to improve the oxidation efficiency of the pollutants in water and wastewater.
- انتشار مقاله: 29-04-1395
- نویسندگان: Hamed Baniamerian,Soheila Shokrollahzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Biotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: silver nanoparticles,Green synthesis,Tollens method,Microbial synthesis,Polysaccharide method
- چکیده:
- چکیده انگلیسی: In the present study, properties of silver nanoparticles (AgNPs) such as average size, size distribution and
morphology were investigated by Tollens, polysaccharide, modified polysaccharide and microbial methods.
The synthesized AgNPs were characterized by UV-visible spectroscopy, scanning electron microscopy
(SEM), transmission electron microscopy (TEM), dynamics light scattering (DLS) and energy dispersive
X-ray (EDX) analyses. Analysis of reaction mixtures confirmed that Tollens, polysaccharide and modified
polysaccharide methods generated smaller AgNPs with better size distribution as compared to that produced
in microbial method. The average size of produced AgNPs by Tollens, polysaccharide and modified
polysaccharide were 42, 30 and 20 nm respectively. Moreover, microbial method generated AgNPs with average size of 54 nm in the case of cell-free filtrate mediated synthesis and 84 nm in case of the supernatant mediated synthesis. Analysis of fungus-mediated synthesis of AgNPs showed that the size distribution of AgNPs produced by supernatant is narrower than that produced by filtrate. Also, cell-free filtrate
resulted in the formation of smaller AgNPs with average size of 59 nm compared to the supernatant. The
comparative analysis of produced AgNPs by the above mentioned methods confirmed that modified polysaccharide method led to the formation of AgNPs with smallest size and highest productivity.- انتشار مقاله: 11-04-1391
- نویسندگان: Sepideh Hamedi,Seyedeh Masumeh Ghaseminezhad,Seyed Abbas Shojaosadati,Soheila Shokrollahzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Fusarium oxysporum,Silver nanoparticles (AgNPs),Controlled Biosynthesis,culture supernatant
- چکیده:
- چکیده انگلیسی: The focus of this study was to evaluate the effects of some parameters influencing the size and size distribution of the silver nanoparticles (AgNPs) produced by culture supernatant of Fusarium oxysporum. Results revealed that in the reaction solution containing equal volume of silver nitrate and culture supernatant; pH, temperature, and light source can control the AgNP’s characteristics. The particle size decreased with an increase in pH. The average size of AgNPs, formed in reaction solutions, decreased as temperature increased from 40 °C to 121 °C. The smallest AgNPs with the highest polydispersity (average size of 14nm and PDI of 0.37) were obtained in reaction solution incubated at 121 °C. Also, the use of UV radiation in reaction solution resulted in the production of the very small AgNPs with the narrowest size distribution (average size of 9.7nm and PDI of 0.2). X-ray diffraction analysis verified the crystalline nature of synthesized AgNPs. Also, transmission electron microscopy analysis confirmed the production of spherical shape nanoparticles.
- انتشار مقاله: 31-03-1395
- نویسندگان: Sepideh Hamedi,Seyed Abbas Shojaosadati,Soheila Shokrollahzadeh,Sameereh Hashemi-Najaf Abadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Immobilization,Mercury ions,Phanerochaete chrysosporium,Loofa sponge,Langmuir adsorption isotherm,Biosorption kinetics
- چکیده:
- چکیده انگلیسی: The sorption behavior of loofa-immobilized Phanerochaete chrysosporium mycelia in two forms, Live (L) and Heat-Inactivated (HIA), was studied for the removal of Hg2+ ions from aqueous solution. Using the Langmuir isotherm, the two key parameters for the sorption performance, qm and the coefficient b, were obtained; the qm values for Hg2+ ions were 72.46 mg/g and 92.59 mg/g and the b coefficients were 0.073 L/mg and 0.114 L/mg for the L and HIA biosorbents, respectively. Using the Freundlich isotherm, the values of kF were determined as 13.28 and 21.30, and the values of the coefficient n were 3.22 and 3.51 for the L and HIA biosorbents, respectively. Although the biosorption data were well fitted by both the Langmuir and Freundlich models, the Langmuir isotherm gave a better fit, with a higher correlation coefficient than the Freundlich model. Moreover, the essential characteristic of the Langmuir isotherm model, described as the separation factor, was indicative of the favorable adsorption of Hg2+ onto both of the test biosorbents (02ads were 1.16×10-3 g/mg·min and 1.08×10-3 g/mg·min for the L and HIA biosorbents, respectively. Regenerating the biosorbents was possible using hydrochloric acid to leach the sequestered mercury ions, providing an easy way to reduce the cost of the process. The prevailing criteria in the industrial selection and use of biosorbents were satisfactorily met by this system.
- انتشار مقاله: 21-10-1388
- نویسندگان: Rosa Bashardoost,Farzaneh Vahabzadeh,Soheila Shokrollahzadeh,Ali Reza Monazzami
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Saccharomyces cerevisiae,Cell membrane transport,Kinetics of phosphate transport,Chemostat culture,Yeast's growth kinetics
- چکیده:
- چکیده انگلیسی: Two different growth media, namely complex and defined media, were used to examine establishment of steady-state conditions in phosphate-limited culture system of Saccharomyces cerevisiae CEN.PK113-5D strain. Using the defined growth medium, it was possible to obtain steady state condition in the continuous culture. The effect of phosphate concentration on the growth of S. cerevisiae in phosphate-limited chemostat was studied at dilution rates between 0.08-0.45 h–1. The cells' growth followed Monod kinetics only over low dilution rates (0.08-0.22 h–1) in which the saturation constant (KS ) and maximum growth rate (μm ) were determined as 10 µM and 0.25 h–1, respectively. By increasing the dilution rates above 0.22 h–1, a significant change in the growth pattern was occurred, possibly due to intracellular accumulation of phosphate and/or extracellular accumulation of ethanol and also increased fermentative activity of the yeast cells. Phosphate transport of the yeast cells via plasma membrane transporters was kinetically characterized in a phosphate-limited chemostat culture. The rate of phosphate transport was measured using 32[P]-labeled orthophosphate in the concentration range of 0.4-2000 µM. High-affinity phosphate transport kinetics was observed over the entire range of dilution rates tested in this study. The corresponding Km values for phosphate were found to be in the range of 1.7 to 36 µM. Dilution rate of 0.22 h–1 showed biphasic pattern for phosphate uptake kinetics while the estimated Km values for this behavior were 1.7 and 284 µM.
- انتشار مقاله: 29-03-1383
- نویسندگان: Soheila Shokrollahzadeh,Farzaneh Vahabzadeh,Babak Bonakdarpour,Mehri Sanati,Bengt L Persson
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: optimization,Wastewater treatment,Membrane technology,Reuse,Bentazon
- چکیده:
- چکیده انگلیسی: Although bentazon is widely used as an agricultural herbicide, it is harmful to humans and poses many environmental threats. This study focused on the treatment of wastewater contaminated with bentazon pesticides using membrane technology. In this regard, low-pressure reverse osmosis (RO) was employed as it has already been used in the removal of other micro-pollutants. The effects of process variables on water flux and bentazon rejection were studied: temperature, pressure, and bentazon feed concentration. Based on central composite design (CCD), the quadratic model was engaged to correlate the process variables with the water flux and the bentazon removal responses. The obtained results showed that the bentazon rejection increased by enhancing the pressure while it decreased at higher feed solution concentration. However, with increasing temperature, the amount of bentazon removal was reduced. A bentazon rejection efficiency of 100 % could be achieved under optimum conditions (i.e., the temperature of 29.8 ℃ and hydrostatic pressure of 12.6 bar for a feed solution concentration of 66.9 mg/L). Therefore, reverse osmosis can effectively remove bentazon.
- انتشار مقاله: 01-03-1399
- نویسندگان: Mohammad Nematzadeh,Abdolreza Samimi,Soheila Shokrollahzadeh,Davod Mohebbi-Kalhori
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Mass transfer,Forward Osmosis (FO),Brine wastewater,concentration polarization
- چکیده:
- چکیده انگلیسی: Forward osmosis (FO) is an energy-saving separation process that can be used in desalination applications. This work investigated the effect of mass transfer phenomenon on the FO desalination process. For this purpose, the water flux was studied through a bench scale system using a flat sheet FO membrane and feeds with various salinity. Then, the mass transfer resistances, which appear in the form of concentration polarization (CP) for the FO process, were evaluated qualitatively and quantitatively, using the collected experimental data and by employing a mathematical model. The results indicated that the increase in feed salinity led to a decrease in water flux due to the counteracted part of the draw solution osmotic pressure, thus leading to a lower effective osmotic pressure and driving force. Also, according to the results, there was a significant difference between the theoretical and experimental fluxes, indicating the influence of the mass transfer effects on the osmotic pressure drop. The modeling results showed that the internal concentration polarization (ICP) still held more contribution to the osmotic pressure loss. Furthermore, it was observed that as the feed solution concentration increased, both the ICP and dilutive external concentration polarization (DECP) decreased, whereas the concentrative ECP (CECP) intensified. Therefore, increasing the CECP led to a significant reduction in the effective osmotic pressure. In addition, increasing the draw solution concentration was accompanied by a much more severe ICP that limited the enhancement of effective flux.
- انتشار مقاله: 12-09-1398
- نویسندگان: Razieh Ahmadizadeh,Soheila Shokrollahzadeh,Seyed Mehdi Latifi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Kinetics,Polycyclic aromatic hydrocarbons (PAHs),Phenanthrene,Biodegradation,Sphingopyxis ummariensis
- چکیده:
- چکیده انگلیسی: The expansion of a microbial bank for the degradation of polycyclic aromatic hydrocarbons (PAHs) is crucial for removal of these persistent pollutants. In this study, five gram-negative, aerobic, non-fermentative bacterial strains (III-R3, IV-P11, IV-P13, IV-R13, and V-P18) were isolated from the activated sludge of a petrochemical wastewater treatment plant using enrichment pro tocol based on phenanthrene. The isolates were capable of utilizing phenanthrene, anthracene, and pyrene as a sole carbon and energy source in an aerobic batch aqueous system. The PAHs biodegradation yields were evaluated by gas chromatography and the bacterial isolates were identified using the 16S rRNA sequencing method. A first-order kinetic model provided the best fit to the phenanthrene degradation profiles with a correlation coefficient value of 0.95-0.98. The phenanthrene biodegradation rate constants and half-lives were measured at the range 0.653--Q.878 day-' and 0.79-1.06 day, respectively. Lower values of Anthracene degradation re sulted with the isolates of the current study, while a relatively high percentage of the removal of Pyrene was obtained by some of the isolates. The data obtained in this study shows that bacterial isolates have degradation preference over Mycobacterium sp. and Pseudomonas aeruginosa; and they are comparable with Pseudomonas stutzeri, Sphingomonas sp., and microbial consortium applied by other researchers. Analysis of the 16S rDNA gene sequence, when compared with the GenBank, indicates that all the strains belong to the genus Sphingopyxis with the nearest type strain being Sphingopyxis ummariensis Ul2 (MTCC 8591T). It is the first time that Sphingopyxis ummariensis is reported for its capability in the degradation of PAHs.
- انتشار مقاله: 30-03-1393
- نویسندگان: Soheila Shokrollahzadeh,Farzaneh Azizmohseni,Fereshteh Golmohamad
- مشاهده