Mohammad Pazouki

Verified email at

Professor, Energy
Materials and Energy Research Center



Environmental Biotechnology
Statistical Optimization


Scopus Publications

Scopus Publications

  • Metronidazole-loaded glass ionomer dental cements
    Ghazaleh Salehi, Aliasghar Behnamghader, Mohamad Pazouki, and Masoud Mozafari

    International Journal of Applied Ceramic Technology, ISSN: 1546542X, eISSN: 17447402, Pages: 1985-1997, Published: 1 July 2020 Wiley

  • Synergistic reinforcement of glass-ionomer dental cements with silanized glass fibres
    Ghazaleh Salehi, Aliasghar Behnamghader, Mohammad Pazouki, Behzad Houshmand, and Masoud Mozafari

    Materials Technology, ISSN: 10667857, eISSN: 17535557, Pages: 433-445, Published: 6 June 2020 Informa UK Limited

  • Bioadsorption and enzymatic biodecolorization of effluents from ethanol production plants
    Zhila Ziaei-Rad, Mojdeh Nickpour, Mehrdad Adl, and Mohammad Pazouki

    Biocatalysis and Agricultural Biotechnology, ISSN: 18788181, Published: March 2020 Elsevier BV

  • Synthesis and characterization of a novel freeze-dried silanated chitosan bone tissue engineering scaffold reinforced with electrospun hydroxyapatite nanofiber
    Nader Nezafati, Raheleh Faridi‐Majidi, Mohammad Pazouki, and Saeed Hesaraki

    Polymer International, ISSN: 09598103, eISSN: 10970126, Pages: 1420-1429, Published: August 2019 Wiley

  • Bioorthogonal surface modified α-TCP-based bone filler for enhancement of apatite formation and bioactivity
    Marzie Moraveji, Nader Nezafati, Mohammad Pazouki, and Saeed Hesaraki

    Ceramics International, ISSN: 02728842, Pages: 5981-5986, Published: 1 April 2019 Elsevier BV
    Abstract The aim of the present study was to investigate the effect of click chemistry reactants on morphology and physico-chemical properties of alpha tricalcium phosphate (α-TCP)-based powders. The powders were synthesized by solid-state reaction. The powders were modified with azide and cycloalkyne to form triazole as a consequence of reactions of these molecules. The presence of the band related to the triazole ring and the click molecules in powder structure was confirmed by Fourier transform infrared (FTIR) and Liquid chromatography- mass spectroscopy (LC-MS) analyses. Based on scanning electron microscopy (SEM) observations, the modified powder exhibited a different microstructure and morphology of apatite precipitates after one day and 7 days of soaking in distilled water and SBF solution, respectively, with respect to unmodified powder. According to the acellular in vitro test, X-ray diffraction (XRD) patterns represented triple characteristic peaks of hydroxyapatite (HA) in modified powder compared with control. Besides, the tendency of conversion of α-TCP to HA is more enhanced for modified powder as well. The SEM analysis depicted the plate-like and needle-like morphology of HA on the surface of modified and control powders, respectively. Since plate-like morphology of HA enhances bone generation and is found in trabecular bone, therefore, a future design can be considered for triazole-modified α-TCP-based fillers as good candidates for bone substitute application.

  • Energy performance evaluation of ultrasonic pretreatment of organic solid waste in a pilot-scale digester
    Mazdak Rasapoor, Mehrdad Adl, Saeid Baroutian, Zeynab Iranshahi, and Mohammad Pazouki

    Ultrasonics Sonochemistry, ISSN: 13504177, eISSN: 18732828, Pages: 517-525, Published: March 2019 Elsevier BV
    It has been proven that ultrasonic pretreatment (UP) has positive effect on biogas generation from previous lab-scale studies. However, that is not always the case in larger scale processes. The purpose of this study was to evaluate the effectiveness of UP to biogas generation in terms of anaerobic digestion process and energy efficiency. Parameters including total solids (TS) and ultrasonic treatment operational parameters of organic solid waste (OSW) resulted from our past lab scale UP studies were applied in this study. OSW with 6-10% TS was treated using a lab-scale ultrasonic processor using various power densities (0.2-0.6 W/mL) at different time periods up to 30 min. Results of lab scale confirmed that OSW with 6% TS sonicated with 0.2 W/mL power density in 30 min gave the best outcome for the pilot scale experiment. To simulate the condition of an actual scale, in addition to energy analysis, two different organic loading rates (OLR), namely 500 and 1500 gVS/m3day were examined. The pilot digester was fed with OSW with or without the pretreatment based on the aforementioned specifications. The results showed that UP effectively improves biogas generation in terms of quantity and quality (CH4/CO2). Furthermore, it decreases the time to reach the maximum cumulative biogas volume comparing to the untreated feed. The key achievement of this research has confirmed that although the relative increase in the energy gain by the influence of UP was more remarkable under the 500 gVS/m3day OLR, energy analysis showed a better energy gain and energy benefit as well as jumping in biogas yield up to 80% for UP treated OSW under 1500 gVS/m3day OLR.

  • Stimuli-responsive Biosynthesis of Gold Nanoparticles: Optimization, kinetics, and thermodynamics of biosorption
    Khalilalrahman Dehvari, Mohammadreza Pazouki and Ali Hosseinia

    International Journal of Engineering, Transactions B: Applications, ISSN: 1728144X, Pages: 1506-1515, Published: 2019 International Digital Organization for Scientific Information (IDOSI)
    Green nanotechnology with the goal of producing sustainable nanomaterials in an eco-friendly approach is becoming an increasing necessity for nanomanufacturing industries. In this regards, biosynthesis is well adopted as a viable method for producing benign nanoparticles for biomedical application. The present study aimed at optimization and study of the effects of external stimuli pH and gold ion concentration on the morphology of biosynthesized gold nanoparticles (GNPs) using Fusarium oxysporum. Based on the central composite design, the experimental method was developed at three levels of the operating parameters; the initial gold ion concentration, cell mass, and pH. The X-ray diffraction and transmission electron microscopy showed that the obtained GNPs were impurity-free while the size and shape of particles were a function of the pH and Au concentration. Also, analysis of variance revealed that the cell mass and initial gold ion concentration have a significant effect on biosynthesis of GNPs. The optimal condition was found at the initial gold ion concentration of 550 μM, pH 3.5, and cell mass of 0.047 mg/mL with the obtained gold uptake of 98.29%. Pseudo-second order kinetics model best fitted the experimental results with the activation energy of 73.8 kJ indicating that complex chemisorption is the mechanism of gold biorecovery. Adsorption equilibrium followed Freundlich adsorption model and negative ΔG value at room temperature suggested that the GNPs can be synthesized at ambient temperature and atmosphere via an eco-friendly and economically viable process. doi: 10.5829/ije.2019.32.11b.01

  • Devulcanization of Ground Tires by Different Strains of Bacteria: Optimization of Culture Condition by Taguchi Method
    Farideh Ghavipanjeh, Zhila Ziaei Rad, and Mohammad Pazouki

    Journal of Polymers and the Environment, ISSN: 15662543, Pages: 3168-3175, Published: 1 August 2018 Springer Science and Business Media LLC
    Biological devulcanization of ground tires (GTs) was evaluated by eleven different bacteria belonging to the genera Thiobacillus, Gordonia, Nocardia, Amycolaptopsis and Pseudomonas. The GTs were treated by each bacterium in a mineral medium and devulcanization was measured by increasing the sulfate of the medium and decreasing the sulfur of the GTs. The effects of incubation time (10 and 20 days) and the percent of ground tire in the medium (0.5 and 5 w/v %) on desulfurization were investigated. No significant changes were observed after 10 days of incubation. The total sulfur contents of all bio-treated GTs were decreased by 6–21% in 0.5% GTs after 20 days of incubation. While in 5% GTs, the total sulfur contents were mainly decreased using Thiobacillus ferroxidans DSMZ 583 and PTCC 1647 up to 27 and 15%, respectively. SEM photograph further indicated a good coherency interface between the bacteria and the GTs. Subsequently, Taguchi method was applied for the optimization of the culture condition of DSMZ 583. An L12 orthogonal array was performed by which the effects of eleven factors in two levels were evaluated. It was found that the amount and mesh size of GTs are the most important factors in biological devulcanization of ground tires.

  • Introducing an attractive method for total biomimetic creation of a synthetic biodegradable bioactive bone scaffold based on statistical experimental design
    Sara Shahbazi, Ali Zamanian, Mohammad Pazouki, and Yaser Jafari

    Materials Science and Engineering C, ISSN: 09284931, Pages: 109-120, Published: 1 May 2018 Elsevier BV
    A new total biomimetic technique based on both the water uptake and degradation processes is introduced in this study to provide an interesting procedure to fabricate a bioactive and biodegradable synthetic scaffold, which has a good mechanical and structural properties. The optimization of effective parameters to scaffold fabrication was done by response surface methodology/central composite design (CCD). With this method, a synthetic scaffold was fabricated which has a uniform and open-interconnected porous structure with the largest pore size of 100-200μm. The obtained compressive ultimate strength of ~35MPa and compression modulus of 58MPa are similar to some of the trabecular bone. The pore morphology, size, and distribution of the scaffold were characterized using a scanning electron microscope and mercury porosimeter. Fourier transform infrared spectroscopy, EDAX and X-ray diffraction analyses were used to determine the chemical composition, Ca/P element ratio of mineralized microparticles, and the crystal structure of the scaffolds, respectively. The optimum biodegradable synthetic scaffold based on its raw materials of polypropylene fumarate, hydroxyethyl methacrylate and nano bioactive glass (PPF/HEMA/nanoBG) as 70/30wt/wt%, 20wt%, and 1.5wt/wt% (PHB.732/1.5) with desired porosity, pore size, and geometry were created by 4weeks immersion in SBF. This scaffold showed considerable biocompatibility in the ranging from 86 to 101% for the indirect and direct contact tests and good osteoblast cell attachment when studied with the bone-like cells.

  • Development of Kinetic Model for Xanthan Production in a Laboratory-Scale Batch Fermentor
    A. Zakeri, M. Pazouki, and M. Vossougi

    Iranian Journal of Science and Technology, Transaction A: Science, ISSN: 10286276, eISSN: 23641819, Pages: 261-266, Published: 1 March 2018 Springer Science and Business Media LLC
    The present study was undertaken to investigate a kinetic model for cell growth evaluation and biopolymer production by Xanthomonas campestris in a laboratory-scale batch fermentor. The optimum conditions selected for biopolymer production were 30 °C for media temperature, 500 rpm for agitation rate, 65 g/l for sugarcane concentration and 1.5 vvm for air flow rate. A detailed, unstructured, mathematical kinetic model is presented here for batch production of xanthan biopolymer from X. campestris. Set of ordinary differential equations were developed as logistic model for X. campestris growth and logistic incorporated Luedeking–Piret model for xanthan production. These models would offer more insights of xanthan optimization with better productivities. The value of specific growth rate μmax of logistic model was 0.026 h−1. The values of α and β are 8.480 and 0.077, respectively, which shows that the xanthan production is growth associated since the value of the growth-associated parameter α is much more than the value of nongrowth-associated parameter β in Luedeking–Piret model.

  • Mercury ion adsorption on AC@Fe3O4-NH2-COOH from saline solutions: Experimental studies and artificial neural network modeling
    Mohammad Pazouki, Mohammad Zabihi, Jalal Shayegan, and Mohammad Hossein Fatehi

    Korean Journal of Chemical Engineering, ISSN: 02561115, Pages: 671-683, Published: 1 March 2018 Springer Science and Business Media LLC
    An efficient, novel functionalized supported magnetic nanoparticle (AC@Fe3O4-NH2-COOH) has been synthesized by co-precipitation method for removal of mercury ions from saline solutions. High dispersed supported magnetic nanoparticles with particle sizes less than 30 nm were formed over activated carbon derived from local walnut shell. Surface characterizations of supported magnetic nanoparticles were evaluated by Boehm test, Brunauer- Emmett-Teller (BET) surface area, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and X-ray fluorescence (XRF). A three-layer artificial neural network (ANN) code was developed to predict the Hg (II) ions removal from aqueous solution by AC@Fe3O4-NH2-COOH. The three-layer back-propagation (BP) is configured of tangent sigmoid transfer function (tansig) at hidden layer with eight neurons for AC@Fe3O4-NH2-COOH, and linear transfer function (purelin) at output layer. According to the calculated MSEs, Levenberg-Marquardt algorithm (LMA) was the best training algorithm among others. The linear regressions between the predicted and experimental outputs were proven to be a good agreement with a correlation coefficient of about 0.9984 for five model variables. Maximum adsorption capacity was achieved 80mg/g by Langmuir isotherm at pH of 7 and salinity of 25,000 ppm. Kinetic studies illustrated that mercury adsorption follows pseudo-second-order.

  • Impact of modified electrodes on boosting power density of microbial fuel cell for effective domestic wastewater treatment: A case study of Tehran
    Fatemeh Nourbakhsh, Mohammad Pazouki, and Mohsen Mohsennia

    Ranliao Huaxue Xuebao/Journal of Fuel Chemistry and Technology, ISSN: 02532409, Pages: 871-879, Published: 1 July 2017 Elsevier BV
    Abstract Utilizing microbial fuel cells (MFCs) is a promising technology for energy-efficient domestic wastewater treatment, but it still faces practical barriers such as low power generation. In this study, the LaMnO3 perovskite-type oxide nanoparticles and nickel oxide/carbon nanotube/polyaniline (NCP) nanocomposite (the cathode and anode catalysts, respectively) have been prepared and used to enhance power density of MFC. The prepared La-based perovskite oxide catalysts were characterized by X-ray diffraction (XRD) and scanning electron microscopies (SEM). The electrocatalytic properties of the prepared catalysts were investigated through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) and Tafel plot at ambient temperature. Results show the exchange current densities of LaMnO3/carbon cloth cathode and NCP nanocomposite/carbon cloth anode were 1.68 and 7 times more compared to carbon cloth cathode, respectively. In comparison to the bare carbon cloth anode, the MFC with the modified electrodes shows 11 times more enhancement in power density output which according to electrochemical results, it can be due to the enhancement of the electron transfer capability. These cathodic and anodic catalysts were examined in batch and semi-continuous modes to provide conditions close to industrial conditions. This study suggests that utilizing these low cost catalysts has promising potential for wastewater treatment in MFC with high power generation and good COD removal efficiency.

  • The effect of synthesis parameters on morphology and diameter of electrospun hydroxyapatite nanofibers
    Raheleh Faridi-Majidi, Nader Nezafati, Mohammad Pazouki, and Saeed Hesaraki

    Journal of the Australian Ceramic Society, ISSN: 0004881X, Pages: 225-233, Published: 1 April 2017 Springer Science and Business Media LLC
    In the present study, hydroxyapatite nanofibers were synthesized by electrospinning. The main focus is based on the effect of adding various ratios of calcium phosphate (Ca-P) sol to polymeric solutions of PVA and PVP with a fixed concentration of 10 and 15% (w/v), respectively, on the morphology and the diameter of the electrospun nanofibers. The electrical conductivity of pure PVA solution was higher than PVP (0.610 versus 0.06 mS/cm). However, by adding Ca-P sol, the solution conductivity increased to 23.5 and 34.4 mS/cm for PVA solution containing 15 (vol%) [A15] and PVP solution containing 25 (vol%) [V25] of the prepared sol, respectively. SEM observations showed that the fiber diameter of sample V25 (average diameter of 150 nm) was thinner and more uniform than A15 (average diameter of 170 nm). FE-SEM of sample V25 confirmed the results of SEM analysis as well. After heat treatment at 600 °C, powder-like particles were formed for the samples obtained from PVA solution without any fibers whereas a spaghetti-like morphology was seen for the samples V15 and V25. X-ray diffractograms of sample V25 indicated the presence of HA phase at two temperatures of 600 and 800 °C. However, in the latter case, minor phases of beta-tricalcium phosphate and calcium oxide were also identified. In addition, the crystal size increased from 2 nm at 600 °C to 16 nm at 800 °C.SEM/EDS analyses confirmed the formation of needle-like HA on surface of V25 after 7 days of soaking in simulated body fluid (SBF). Evaluation of cell growth demonstrated that human osteoblast-like cells were attached, spread, and grown well on the surface of V25. This event could be a good sign of biocompatibility of the fibers.

  • Economic analysis of biomass gasification-solid oxide fuel cell-gas turbine hybrid cycle
    International Journal of Renewable Energy Research, eISSN: 13090127, Pages: 1007-1018, Published: 2017

  • Nickel oxide/carbon nanotube/polyaniline nanocomposite as bifunctional anode catalyst for high-performance Shewanella-based dual-chamber microbial fuel cell
    Fatemeh Nourbakhsh, Mohsen Mohsennia, and Mohammad Pazouki

    Bioprocess and Biosystems Engineering, ISSN: 16157591, eISSN: 16157605, Pages: 1669-1677, Published: 2017 Springer Science and Business Media LLC
    Abstract A novel nickel oxide/carbon nanotube/polyaniline (NCP) nanocomposite has been prepared and used to modify the electrocatalytic properties of carbon cloth anode in fabricating dual-chamber MFC. The prepared nanocomposite was characterized by scanning electron microscopy, X-ray diffraction, and fourier transform infrared spectroscopy. The carbon cloth coated with the NCP nanocomposite showed the enhanced electrochemical performance as compared to bare carbon cloth anode. The electrochemical properties of the fabricated MFC with the modified anode have been investigated by linear sweep voltammetry and electrochemical impedance spectroscopy. The maximum power density of the MFC using the novel NCP nanocomposite-carbon cloth anode increased by 61.88% compared to that of the bare carbon cloth anode. In comparison to the bare carbon cloth anode, the new composite anode showed 26.8% enhancement of current density output which it can be due to the enhancement of the charge transfer capability.

  • Simultaneous control of rod length and pore diameter of SBA-15 for PPL loading
    Maryam Ferdousi, Mohammad Pazouki, Fereydoun Alikhani Hessari, and Mahmood Kazemzad

    Journal of Porous Materials, ISSN: 13802224, eISSN: 15734854, Pages: 453-463, Published: 1 April 2016 Springer Science and Business Media LLC
    Mesoporous silica materials are attractive materials for immobilizing enzymes because of their well-ordered structures, large surface area are pore volume. Diffusion of large enzyme molecules such as porcine pancreatic lipase (PPL) through the lengthy channels of MPS takes place too slowly. Therefore, the squat of the enzyme at the pore mouth entrance, actually makes the rest of the channel useless. In this study, to overcome this problem, synthesis parameters of SBA-15 were changed, since along with pore diameter increasing, the mesochannel length becomes shorter. The main point to obtain a well-ordered 2D hexagonal pore structure was the pre-hydrolysis of tetraethyl orthosilicate (TEOS) before the addition of 1,3,5-trimethyl benzene as a micelle swelling agent. Due to the strong effect of zirconium in changing the morphology of SBA-15 particles, we modified SBA-15 in the presence of a small amount of ZrOCl2 in the synthesis solution under acidic conditions. As a result, mesochannel length of SBA-15-Zr was shortened from 600 to <200 nm. The morphology of mesoporous silica was also changed from rod-like to platelet, because of the accelerating effect of Zr(IV) on the self-assembly rate of P123 and TEOS condensation. Characteristic results conducted by low angle XRD, high resolution transmission electron microscopy and nitrogen adsorption, confirmed tuning effect of Zr(IV) in SBA-15. Furthermore, it was shown that the number of pore entrances increases with decreasing the length of SBA-15 mesochannels, leading to obvious improvement of enzyme uptake. PPL has been successfully immobilized in the mesoporous channels of SBA-15-Zr. The total amount of lipase adsorbed on the mesoporous SBA-15-Zr was measured by thermal gravimetric analysis. The largest PPL adsorption capacity was 784 mg/g belonging to the SBA-15-Zr with the length of 150 nm and the mean pore size diameter of 9.22 nm.

  • Biosynthesis of Ag/MWf-CNT Nanocomposites Using Aspergillus fumigatus as the CO Oxidation Catalyst
    Naser Yousefi, Mohammad Pazouki, Mehdi Alizadeh, and Fereydoon alikhani Hesari

    Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry, ISSN: 15533174, eISSN: 15533182, Pages: 464-470, Published: 3 March 2016 Informa UK Limited
    In this research, the biosynthesis process of an Ag nanoparticles/multiwalled carbon nanotubes (Ag/MWf-CNT) catalyst system has been investigated by Aspergillus fumigatus fungus. Characteristic peaks of pure silver and FCC crystallization systems were characterized by X-ray diffraction pattern. TEM images show a well-dispersed spherical silver nanoparticles (≤10 nm) on the carbon nanotubes. Based on the results, reduction of silver ions is mainly dependent on the biomass weight applied in the biosynthesis process. Catalytic activity in CO/CO2 conversion process revealed approximately 100% conversion of CO at 220°C.

  • Experimental study on the factors affecting hexavalent chromium bioreduction by Bacillus cereus
    Maryam Emadzadeh, Mohammad Pazouki, Elham Abdollahzadeh Sharghi and Lobat Taghavi

    International Journal of Engineering, Transactions B: Applications, ISSN: 1728144X, Pages: 152-159, Published: February 2016 International Digital Organization for Scientific Information (IDOSI)
    In this work, batch studies were conducted to evaluate the effect of environmental factors on the rate of Cr(VI) reduction from synthetic wastewater of metal plating industry by Bacillus cereus. The effect of different inoculum volumes (5, 10, 15 and 20 mL), pH (5, 7 and 9), temperatures (20, 30 and 40 °C) and initial concentrations of Cr(VI) (10, 50, 100 and 200 mg/L) for the best performance of chromium removal were investigated during 72 h of cultivation by Bacillus cereus. Complete reduction of Cr(VI) by Bacillus cereus was achieved after 48 h of incubation under optimized conditions of pH 7, inoculum volume of 5 mL, initial chromium concentration of 50 mg/L, and temperature of 40 °C. The results showed the highest rate of reduction at the lowest Cr(VI) concentration (0.104 mg/L.h). Atomic absorption spectroscopy analyses under optimized conditions showed the concentration of Cr(III) in the culture supernatant was 49 mg/L after 48 h. The presence of almost all the reduced Cr(III) in the supernatant revealed Cr(VI)-reductase in Bacillus cereus is mainly associated with the soluble fraction of the enzyme. High Cr(VI) concentration resistance and high Cr(VI) reducing ability of Bacillus cereus make it a suitable candidate for bioremediation. doi: 10.5829/idosi.ije.2016.29.02b.03

  • Room temperature synthesis of n-doped urchin-like rutile TiO2 nanostructure with enhanced Photocatalytic activity under sunlight
    International Journal of Engineering, Transactions A: Basics, ISSN: 17281431, Pages: 1188-1195, Published: October 2015

  • Evaluation of biodevulcanized waste ground tire in revulcanization process
    Farideh Ghavipanjeh, Z. Ziaei Rad and Mohammad Pazouki

    International Journal of Engineering, Transactions A: Basics, ISSN: 17281431, Pages: 1-6, Published: 1 January 2015 International Digital Organization for Scientific Information (IDOSI)

  • A novel soluble nano-catalysts in diesel-biodiesel fuel blends to improve diesel engines performance and reduce exhaust emissions
    Mehrdad Mirzajanzadeh, Meisam Tabatabaei, Mehdi Ardjmand, Alimorad Rashidi, Barat Ghobadian, Mohammad Barkhi, and Mohammad Pazouki
    ISSN: 00162361, Volume: 139, Pages: 374-382, Published: 1 January 2015 Elsevier BV
    Abstract This study was aimed at synthesizing a novel soluble hybrid nanocatalyst to decrease emissions i.e., nitrogen oxide compounds (NO x ), carbon monoxide (CO), unburned hydrocarbons (HC) and soot, of a DI engine fueled with diesel–biodiesel blends. Moreover, enhancement of performance parameters i.e. power, torque and fuel consumption was also simultaneously targeted. The hybrid nanocatalyst containing cerium oxide on amide-functionalized multiwall carbon nanotubes (MWCNT) was investigated using two types of diesel–biodiesel blends (B5 and B20) at three concentrations (30, 60 and 90 ppm). The results obtained revealed that high surface area of the soluble nano-sized catalyst particles and their proper distribution along with catalytic oxidation reaction resulted in significant overall improvements in the combustion reaction specially in B20 containing 90 ppm of the catalyst B20 (90 ppm) . More specifically, all pollutants i.e., NO x , CO, HC and soot were reduced by up to 18.9%, 38.8%, 71.4% and 26.3%, respectively, in B20 (90 ppm) compared to neat B20. The innovated fuel blend also increased engine performance parameters i.e., power and torque by up to 7.81%, 4.91%, respectively, and decreased fuel consumption by 4.50%.

    Mohammad Raouf Hosseini, Mahin Schaffie, Mohammad Pazouki, and Mohammad Ranjbar

    Chemical Engineering Communications, ISSN: 00986445, eISSN: 15635201, Volume: 201, Pages: 160-170, Published: February 2014 Informa UK Limited
    The influence of a direct electric current on the growth, protein secretion, and glucose consumption by Fusarium oxysporum was determined. An electrochemical cell with titanium electrodes was inoculated with F. oxysporum and incubated for 5 days in the presence of 1, 5, and 10 mA current densities. The current reduced the fungal growth compared to the control culture. However, protein generation doubled after 3 days. Also, the glucose consumption increased significantly. Finally, the fitness of the growth, protein, and glucose concentration data to the logarithmic and Ludeking-Piret models was respectively investigated, and the effect of electric current on the model parameters was explained.

  • Synthesis and characteristics of mesoporous sol-gels for lipase immobilization
    Mohsen Nickpour and Mohammad Pazouki

    International Journal of Engineering, Transactions A: Basics, ISSN: 17281431, Pages: 1495-1502, Published: 1 October 2014 International Digital Organization for Scientific Information (IDOSI)
    Enzyme cost is the major problem for industrial scale application. Immobilization is a promising approach to moderate the enzyme cost factor and increase its stability and activity. In this study, sol-gel method was used to prepare the immobilization platform and entrapped lipase as one of the most used enzyme in dairy processing, cosmetics and pharmaceutical industries. Lipase from Candida rugosa was immobilized onto glycidoxypropyltrimethoxysilane (GPTMS) and tetramethoxysilane (TMOS) derived sol-gels and its characteristics and hyrdrolytic activity were investigated. Michaelis-Menten kinetic properties reveal that although free enzyme can catalyze the reaction faster, but it has lower affinity for substrate molecules compared to sol-gel immobilized lipase. Entrapped lipase retained 67 % of its initial activity after six reaction cycles. It showed 100% activity compared to free lipase powder at 40-45 °C. In pH 9, as free enzyme lost 90 % of its initial activity, immobilized lipase lost only 29% of its activity. Immobilized enzyme was more stable toward different pHs (100% activity at pH 7.5 compared to free form). Morphological characteristics of the immobilized enzyme were investigated by SEM images and BET. The sample had specific surface area and mean pore diameter of 2.599 m 2 /g and 46.13 nm, respectively.

  • Development of clay foam ceramic as a support for fungi immobilization for biodiesel production
    Mohammad Reza Pazouki, Farzaneh Zamani and Mojtaba Khalili

    International Journal of Engineering, Transactions B: Applications, ISSN: 1728-144X, Pages: 1691-1696, Published: 1 November 2014 International Digital Organization for Scientific Information (IDOSI)
    Biodiesel is an attractive alternative fuel because of its nontoxicity and biodegradability. Biodiesel is produced through transesterification of vegetable oils' triglyceride. It is obtained from vegetable oils or fats either by chemical or enzyme-cataly zed transesterification with methanol or ethanol. Use of whole-cell biocatalyst immobilized within biomass support particles (BSPs) can overcome the obstacle of high cost of enzymatic catalyst. The objective of this research is to produce clay foam ceramic as BSP by replica method from raw materials such as clay, sodium silicate and sodium tripolyphosphate. To prepare the whole cell biocatalyst Rhizopus oryzae fungi (PTCC 5174) was immobilized on the ceramic foam with bulk density and porosity of 0.3 g/cm 3 and 88.8%, respectively. The deposited biomass on clay foam particles can be observed through scanning electronic microscopy (SEM). A packed-bed reactor (PBR) system using whole-cell biocatalyst was developed for biodiesel production by pretreated used cooking oil (UCO). Clay foam ceramic seems to be more suitable compared to polyurethane foam for supporting fungi immobilization because it shows high mechanical strength and reduces damaged microorganisms.

  • Improvement of the solvent extraction of rhenium from molybdenite roasting dust leaching solution using counter-current extraction by a mixer-settler extractor
    Mostafa Hosseinzadeh, Mehdi Alizadeh, Mohammad Ranjbar and M. Hossein Pazouki

    International Journal of Engineering, Transactions A: Basics, ISSN: 17281431, eISSN: 17359244, Pages: 651-658, Published: April 2014 International Digital Organization for Scientific Information (IDOSI)
    Continuous counter-current extraction of rhenium from roasting dust leach liquor was carried out using a mixer-settler extractor. Tributylphosphate was used as the extractant diluted in kerosene. The effects of the flow rates and extraction stages were investigated. The extraction efficiency was affected by the flow rates of the aqueous and organic phases, and its mechanism was qualitatively discussed on the basis of the stoichiometric relations of the extraction. Rhenium extraction mass balance and simulation in the mixer-settler was also studied. A high rhenium extraction percentage (95.43%) in the phase ratio 1:1 was achieved using a counter-current four-stage extraction process. The continuous counter-current extraction technique was used in this research work showed to be effective for rhenium extraction from the leach solutions of the dust of the molybdenite roasting furnaces.

  • Biogenesis of nanoparticles with potential applications as semiconductor from chalcopyrite concentrate
    Mohammad Raouf Hosseini, Mahin Schaffie, Mohammad Pazouki, Majid Lotfalian, Axel Schippers, and Mohammad Ranjbar

    Advanced Materials Research, ISSN: 10226680, Volume: 825, Pages: 92-95, Published: 2013 Trans Tech Publications, Ltd.
    Nanostructure forms of semiconductor materials are of great interest. Among these compounds, copper sulfide as a variable stoichiometric composition attracts considerable attention. In the present study, copper sulfide nanoparticles were synthesized biologically from a chalcopyrite concentratemainly containing chalcopyrite (46%) and pyrite (23%). Firstly, the copper contents of the concentrate were bioleached using thermophile bacteria, then the grownFusarium oxysporumwas added to the prepared solution and the biosynthesized nanoparticles collected and their characteristics compared with the product derived from the pure copper sulfate solution. The characterization was performed by UV spectrometry, Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDS), Thermogravimetery (TG), Differential Scanning Calorimetery (DSC), Mass Spectrometery (MS), and Transmission Electron Microscopy (TEM). Finally, it wasproved that the produced nanoparticles had a covellite composition and their size was about 5-40 nm.

  • Preparation of micro and nanostructured titania compounds from ilmenite concentrates
    Behzad N. Akhgar, M. Pazouki, Behrang N. Akhgar, M. Ranjbar, and A. Hosseinnia

    International Journal of Mineral Processing, ISSN: 03017516, Volume: 124, Pages: 138-140, Published: 2013 Elsevier BV
    Abstract Preparation of titania compounds by double-reductive hydrochloric acid leaching of ilmenite concentrate is reported. A rod-shaped nanostructure titania compound was obtained via centrifugation of leach liquors as a by-product. The liquors of leaching experiments were subjected to zetasizer test. The suspended particles in leach liquors were investigated using SEM and TEM analysis. The results revealed that the rod-shaped particles were smaller than 100 nm in width. The XRD analysis verified the formation of rutile and pseudorutile phases as main phases. Regarding to the XRF analysis, The TiO 2 content of ilmenite increased from 33% in ilmenite concentrate to about 80% in the products containing some constituents such as Fe 2 O 3 , SiO 2 and Al 2 O 3 .

  • A novel electrically enhanced biosynthesis of copper sulfide Nanoparticles
    M.R. Hosseini, M. Schaffie, M. Pazouki, A. Schippers, and M. Ranjbar

    Materials Science in Semiconductor Processing, ISSN: 13698001, Pages: 250-255, Published: April 2013 Elsevier BV
    Abstract The slow rate of nanoparticle production is one of the drawbacks of the biological synthesis of nanoparticles. In this study, a novel electro-biosynthesis process was introduced in order to improve the speed of nanoparticle bio-production. Electric current with three different magnitudes was applied to the cultures of Fusarium oxysporum , and then these electrified cultures were used for the biosynthesis of copper sulfide nanoparticles from CuSO 4 solution. Results proved that although this approach reduced the fungal growth, it significantly tripled the rate of biosynthesis process in contrast to the control culture to which no current was applied. However, the positive influence of electric current on the final amount of the produced nanoparticles was not statistically significant. Finally, the biosynthesized nanoparticles were characterized using Thermo Gravimetry (TG), Differential Scanning Calorimetry (DSC), Mass Spectrometry (MS), Energy Dispersive X-ray spectroscopy (EDX), Scanning (SEM) and Transmission Electron Microscopy (TEM).

  • Comparative of the removal of Pb 2+, Cd 2+ and Ni 2+ by nano crystallite hydroxyapatite from aqueous solutions: Adsorption isotherm study
    I. Mobasherpour, E. Salahi, and M. Pazouki

    Arabian Journal of Chemistry, ISSN: 18785352, Pages: 439-446, Published: October 2012 Elsevier BV
    Abstract Release of heavy metal onto the water and soil as a result of agricultural and industrial activities may pose a serious threat to the environment. In this study, the adsorption behavior of nano hydroxyapatite with respect to Pb 2+ , Cd 2+ and Ni 2+ has been studied in order to consider its application to purity metal finishing wastewater. The batch method has been employed, using metal concentrations in solution ranging from 100 to 400 mg/L. The uptake capacity and distribution coefficients ( K d ) were determined for the adsorption system as a function of sorbate concentration. The Langmuir, Freundlich, and Dubinin–Kaganer–Radushkevich (DKR) isotherms applied for sorption studies showed that the amount of metal sorbed on nano hydroxyapatite. It was found that the adsorption phenomena depend on charge density and hydrated ion diameter. According to the equilibrium studies, the selectivity sequence can be given as Pb 2+ > Cd 2+  > Ni 2+ . These results show that nano hydroxyapatite holds great potential to remove cationic heavy metal species from industrial wastewater.

  • Kinetic modeling of the bioleaching process of iron removal from kaolin
    E. Aghaie, M. Pazouki, M.R. Hosseini, and M. Ranjbar

    Applied Clay Science, ISSN: 01691317, Volume: 65-66, Pages: 43-47, Published: September 2012 Elsevier BV
    A kinetic model was developed to assess the influence of batch cultivation of Aspergillus niger on the bioleaching of iron from kaolin. A simple model was proposed using the logistic equation for growth, and the Luedeking–Piret equations for iron removal, acid formation and sucrose consumption. The performance of the model was compared against that obtained by the empirically experimental data. The model provides a reasonable description for each parameter during the growth phase. The experimental results also suggest that the product formation depends upon both the instantaneous biomass concentration, and growth rate.

  • Biologically synthesized copper sulfide nanoparticles: Production and characterization
    M.R. Hosseini, M. Schaffie, M. Pazouki, E. Darezereshki, and M. Ranjbar

    Materials Science in Semiconductor Processing, ISSN: 13698001, Pages: 222-225, Published: April 2012 Elsevier BV
    abstract In the present research, copper sul“de nanoparticles were synthesized through a low-cost and environmentally friendly method using the fungusFusarium oxysporumfor the“rst time. The extracellularly generated nanoparticles were characterized by UV vis,Florescence Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and Trans-mission Electron Microscopy (TEM). According to the UV vis, Florescence and FTIRanalysis, it was con“rmed that the biosynthesized nanoparticles were created of coppersul“de composition. Moreover, from the morphological point of view, TEM imagesdemonstrated that spherical particles having the size of 2 5 nm were entangled inspherical peptide shells which were about 20 nm in diameter.& 2012 Elsevier Ltd. All rights reserved. 1. IntroductionNanostructure forms of semiconductor materials are ofgreat interest due to their fascinating speci“cations whichare distinctly different from the same substances in thebulk type. Therefore, synthesis and control of the size andmorphology of the chalcogenide nanocrystals have beenthe researchers main concern[1]. Nowadays, the studyof semiconductor metal sul“des like the compounds ofgroup IB VIA, IIB VIA, IVA VIA, VA VIA, and VIB VIA isgrowing rapidly. Among these compounds, copper sul“deas a variable stoichiometric composition attracts consid-erable attention [2]. This variability causes copper sul“deto exhibit many unusual electronic and optic behaviorsthat make it a great potential in a wide range of applica-tions [3] such as solar cells, solar controllers, solarradiation absorbers, catalysts, nanometer-scale switches,high-capacity cathode materials in lithium secondarybatteries, superconductors at low temperature, chemicalsensors, and thermoelectric cooling materials[3,4]. More-over, considering the optical functions, copper sul“de thin“lms, which maintain transmittance in the infraredregion, have a low re”ectance in the visible region andrelatively high re”ectance in the near infrared region.Such features make these particles suitable to beemployed in making optical “lters, sensors, and architec-tural glazes [5]. Copper sul“de nanoparticles have beenproduced by a variety of methods[1 6]; however, theincreasing interest in developing an environmentallyfriendly approach for nanoparticle synthesis requiresscientists to exploit the biological systems in order tomanufacture nanoscale structures[7,8].Many microorganisms are recognized as suitable formetallic nanoparticle production through an enzymaticprocess either intracellularly or extracellularly[7,9]. Inextracellular synthesis, NADH dependent enzymes aresecreted by organisms such as fungi and bacteria, andContents lists available atSciVerse ScienceDirectjournal

  • Application of Taguchi method for optimization of synthetic rutile nano powder preparation from ilmenite concentrate
    B.N. Akhgar, M. Pazouki, M. Ranjbar, A. Hosseinnia, and R. Salarian

    Chemical Engineering Research and Design, ISSN: 02638762, Pages: 220-228, Published: February 2012 Elsevier BV
    Abstract In the present research work Taguchi method was applied to investigate the effect of reductive leaching parameters and mechanical pretreatment of ilmenite on nano synthetic rutile synthesis. The parameters such as ilmenite to acid mass ratio, ilmenite to iron powder mass ratio, milling time and initial leaching temperature were selected for optimization of experimental conditions. Consequently, the milling time was the most effective parameter on synthetic rutile preparation compared to the rest of the selected parameters. The optimum conditions obtained were as follows: milling in Argon atmosphere 40 min, initial reaction temperature 100 °C, ilmenite to hydrochloric acid mass ratio 1:9.55 and ilmenite to iron powder mass ratio 1:0.075. The characterization of products indicated that the prepared powder with milling time 40 min, temperature 100 °C, ilmenite to hydrochloric acid mass ratio 1:12.8 and ilmenite to iron powder mass ratio 1:0.05 had particles size of less than 100 nm. The analysis further confirmed that synthetic rutile nano powder had 91.1% TiO 2 . The nano powder obtained under the optimized condition had a BET surface area of 54.6 m 2 /g.

  • Optimizing of Iron bioleaching from a contaminated kaolin clay by the use of artificial neural network
    M. Pazouki

    International Journal of Engineering, Transactions B: Applications, ISSN: 1728-144X, eISSN: 17359244, Pages: 81-87, Published: May 2012 International Digital Organization for Scientific Information (IDOSI)

  • Removal of nickel (II) from aqueous solutions by using nano-crystalline calcium hydroxyapatite
    I. Mobasherpour, E. Salahi, and M. Pazouki

    Journal of Saudi Chemical Society, ISSN: 13196103, Pages: 105-112, Published: April 2011 Elsevier BV
    Abstract The potential of the synthesized nano-hydroxyapatite to remove Ni 2+ from aqueous solutions was investigated in batch reactor under different experimental conditions. The study also investigates the effects of process parameters such as initial concentration of Ni 2+ ion, temperature, and adsorbent mass. Various thermodynamic parameters, such as Δ G ° , Δ H ° and Δ S ° have been calculated. The thermodynamics of Ni 2+ ion onto nano-HAp system indicates spontaneous and endothermic nature of the process. Nickel uptake was quantitatively evaluated using the Langmuir, Freundlich and Dubinin–Kaganer–Radushkevich model. The adsorption data follow the adsorption equilibrium was described well by the Langmuir isotherm model with maximum adsorption capacity of 46.17 mg/g of Ni 2+ ions on nano-HAp.

  • Experimental investigation of forced convective heat transfer coefficient in nanofluids of Al2O3/EG and CuO/EG in a double pipe and plate heat exchangers under turbulent flow
    Amirhossein Zamzamian, Shahin Nasseri Oskouie, Ahmad Doosthoseini, Aliakbar Joneidi, and Mohammad Pazouki

    Experimental Thermal and Fluid Science, ISSN: 08941777, Pages: 495-502, Published: April 2011 Elsevier BV
    Nanofluid is the term applied to a suspension of solid, nanometer-sized particles in conventional fluids; the most prominent features of such fluids include enhanced heat characteristics, such as convective heat transfer coefficient, in comparison to the base fluid without considerable alterations in physical and chemical properties. In this study, nanofluids of aluminum oxide and copper oxide were prepared in ethylene glycol separately. The effect of forced convective heat transfer coefficient in turbulent flow was calculated using a double pipe and plate heat exchangers. Furthermore, we calculated the forced convective heat transfer coefficient of the nanofluids using theoretical correlations in order to compare the results with the experimental data. We also evaluated the effects of particle concentration and operating temperature on the forced convective heat transfer coefficient of the nanofluids. The findings indicate considerable enhancement in convective heat transfer coefficient of the nanofluids as compared to the base fluid, ranging from 2% to 50%. Moreover, the results indicate that with increasing nanoparticles concentration and nanofluid temperature, the convective heat transfer coefficient of nanofluid increases. Our experiments revealed that in lower temperatures, the theoretical and experimental findings coincide; however, in higher temperatures and with increased concentrations of the nanoparticles in ethylene glycol, the two set of results tend to have growing discrepancies.

  • Room temperature synthesis of nanocrystalline anatase sols and preparation of uniform nanostructured TiO2 thin films: Optical and structural properties
    M Hosseingholi, M Pazouki, A Hosseinnia, and S H Aboutalebi

    Journal of Physics D: Applied Physics, ISSN: 00223727, eISSN: 13616463, Published: 9 February 2011 IOP Publishing
    Transparent TiO2 thin films were deposited on soda-lime glass substrates via the sol?gel method using a nanocrystalline TiO2 sol solution prepared at room temperature employing the dip-coating method. The effects of pH on crystallinity, particle size and stability of the synthesized TiO2 sols were investigated, systematically. TiO2 thin films were thickened by means of a sequential dip-coating process. The TiO2 films were transparent and exhibited proper adherence. The effects of thickness and annealing temperature on the structural and optical properties of the thin films were evaluated. The prepared powder was crystalline without any thermal treatment. The crystallite size of the particles (anatase) was in the range 4.2?12.1?nm depending on the initial pH value. Although only the anatase phase was observed at room temperature and 400??C, a further increase in annealing temperature up to 700??C resulted in the formation of the rutile phase. Even at high annealing temperatures, fairly smooth and homogeneous surfaces with no cracks and pores were observed. It was demonstrated that the films were transparent in the visible region with characteristic absorption in the UV region. Band gap of the as-deposited film was estimated to be 3.34?eV and was found to decrease with increasing annealing temperature.

  • Removal of divalent cadmium cations by means of synthetic nano crystallite hydroxyapatite
    I. Mobasherpour, E. Salahi, and M. Pazouki

    Desalination, ISSN: 00119164, Volume: 266, Issue: 1-3, Pages: 142-148, Published: 31 January 2011 Elsevier BV
    Abstract Nano crystallite hydroxyapatite were prepared by a wet method from aqueous solutions and characterized using TEM, XRD, and BET-N2 adsorption measurements. The potential of the synthesized nano crystallite hydroxyapatite to remove Cd2+ cations from aqueous solutions was investigated in batch reactor under different experimental condition. The processing parameters such as initial concentration of Cd2+ ions, temperature, adsorbent mass and pH were also investigated. Cadmium uptake was quantitatively evaluated using the Langmuir, Freundlich and Dubinin–Kaganer–Radushkevich (DKR) models. At 400 mg/L of initial Cd2+ cations concentration adsorption capacity increased from 142 to 202 mg/g by increasing of temperature from 25 to 70 °C, an indication of the endothermic nature of adsorption process. In addition, the adsorption equilibrium was described well by the Langmuir isotherm model with maximum adsorption capacity of 142.857 mg/g of Cd2+ cations on nano crystallite HAp. Various thermodynamic parameters, such as ΔG°, ΔH° and ΔS° were calculated. The thermodynamics of Cd2+ cations adsorption onto nano HAp system pointed at spontaneous and endothermic nature of the process.

  • Biodiesel production from genetically engineered microalgae: Future of bioenergy in Iran
    Meisam Tabatabaei, Masoud Tohidfar, Gholamreza Salehi Jouzani, Mohammadreza Safarnejad, and Mohammad Pazouki

    Renewable and Sustainable Energy Reviews, ISSN: 13640321, Pages: 1918-1927, Published: May 2011 Elsevier BV
    Current biomass sources for energy production in Iran include sewerage as well as agricultural, animal, food industry and municipal solid wastes, and are anticipated to account for about 14% of national energy consumption in near future. However, due to the considerable progress made in genetic engineering of various plants in Iran during the last decade and the great potentials of microalgae for biofuel production, these photosynthetic organisms could be nominated as the future source of bioenergy in Iran. An overview of status of bioenergy in the world and Iran as well as the potential and utilization of biomass in Iran is presented. The possibilities of increasing biofuel production through microalgal genetic engineering and the progress made so far are discussed. Biodiesel in the Iran and its future prospective is also reviewed, emphasizing the promising role of microalgae.

  • Photocatalytic reaction of aryl amines/alcohols on TiO2 nanoparticles
    Azarmidokht Hosseinnia, Mohammad Pazouki, and Ketauon Karimian

    Research on Chemical Intermediates, ISSN: 09226168, eISSN: 15685675, Pages: 937-945, Published: November 2010 Springer Science and Business Media LLC
    In this article, the photocatalytic reaction of aniline and 4-amino N, N dimethyl aniline with methanol, ethanol and isopropanol on anatase TiO2 nano-particles under UV (365 nm wavelength) irradiation was examined. The concentration of unreacted aryl amines and products was measured by gas chromatography picks integration, and then the products were identified by mass spectroscopy analysis. By making a comparison within the rates of photocatalysis of each aryl amine in different alcohols under various irradiation times, it was revealed that, in all cases, the sequence of photocatalysis rate was methanol > ethanol > isopropanol. In reactions where the concentrations of aryl amine were lower than 10 mmol/L, imines were the main products and alkylation of amines was not observed. In the higher concentration of aryl amines, oxidation and dimerization occurred.

  • Biodegradation of phenanthrene in an anaerobic batch reactor: Growth kinetics
    Nasrollahzadeh H.S., Najafpour G.D., Pazouki M., Younesi H., Zinatizadeh A.A., and Mohammadi M.

    Chemical Industry and Chemical Engineering Quarterly, ISSN: 14519372, Pages: 157-165, Published: 2010 National Library of Serbia

  • Photocatalytic reaction of arylamines/alcohols on TiO2 nano-particles
    Azarmidokht Hosseinnia, Mohammad Pazouki, and Ketauon Karimian

    Research on Chemical Intermediates, ISSN: 09226168, eISSN: 15685675, Pages: 373-381, Published: June 2010 Springer Science and Business Media LLC
    In this article, the photocatalytic reaction of aniline and 4-amino N,N-dimethyl aniline with methanol, ethanol and isopropanol on anatase TiO2 nano-particles under UV (365-nm wavelength) irradiation was examined. The concentration of unreacted arylamines and products was measured by gas chromatography picks integration, and then the products were identified by mass spectroscopy analysis. By making a comparison within the rates of photocatalysis of each arylamine in different alcohols under various irradiation times, it was revealed that, in all cases, the sequence of photocatalysis rate was methanol > ethanol > isopropanol. In reactions where the concentrations of arylamine were lower than 10 mmol/l, imines were the main products and the alkylation of amines was not observed. In the higher concentration of arylamines, oxidation and dimerization was occurred.

  • Preparation of nanosized synthetic rutile from ilmenite concentrate
    B.N. Akhgar, M. Pazouki, M. Ranjbar, A. Hosseinnia, and M. Keyanpour-Rad

    Minerals Engineering, ISSN: 08926875, Pages: 587-589, Published: June 2010 Elsevier BV
    Abstract In this paper, the preparation of nanosized synthetic rutile by reductive hydrochloric acid leaching of mechanically activated ilmenite concentrate (FeTiO 3 ) is discussed. X-ray fluorescence analysis of the nanosized rutile which forms by rapid hydrolysis of dissolved titanium indicates that the powder contains 91.1% TiO 2 , 1.3% Fe 2 O 3 , 6.3% SiO 2 . The presence of the rutile phase is confirmed by X-ray diffractometry and the sizes of particles are measured by transmission electron microscopy to be less than 100 nm. The photocatalytic activity of nanosized rutile is observed by the decomposition of methylene blue.

  • Investigation of culture conditions for biosynthesis of silver nanoparticles using Aspergillus fumigatus
    Iranian Journal of Biotechnology, ISSN: 17283043, Pages: 56-61, Published: January 2010

  • Synthesis of TiO2-Ag nanocomposite with sol-gel method and investigation of its antibacterial activity against E. coli
    Shahab Ansari Amin, Mohammad Pazouki, and Azarmidokht Hosseinnia

    Powder Technology, ISSN: 00325910, Volume: 196, Pages: 241-245, Published: 22 December 2009 Elsevier BV
    Abstract TiO 2 –Ag nanocomposite was prepared by the sol–gel method and an azeotropic distillation with benzene was used for dehydration of the gel. Because of gel dehydration by distillation method a nanopowder with a surface area of 230 m 2 /g was produced which decreased to 80 m 2 /g after calcination. TEM micrographs and XRD patterns showed that spherical nanosized Ag particles (≈ 10 nm) were deposited among TiO 2 particles. The antibacterial activity of calcined powder at 300 and 500 °C was studied in the presence and in the absence of UV irradiation against Escherichia coli as a model for Gram-negative bacteria. The antibacterial tests confirmed the powder calcined at 300 °C possessed more antibacterial activity than the pure TiO 2 , amorphous powder and the powder calcined at 500 °C under UV irradiation. In the absence of UV, the reduction in viable cells was observed only with calcinated powder at 300 °C.

  • Effects of process factors on biological activity of granular sludge grown in an UASFF bioreactor
    A.A.L. Zinatizadeh, H. Younesi, H. Bonakdari, M. Pirsaheb, M. Pazouki, G.D. Najafpour, and M. Hasnain Isa

    Renewable Energy, ISSN: 09601481, Pages: 1245-1251, Published: May 2009 Elsevier BV
    Control and operation of a hybrid granular sludge reactor are mainly related to biological behavior of the granules under different process conditions. In this study, a 1-l digester was used to examine biological activity of the granules grown in a hybrid anaerobic reactor (AHR). The biogas production process was modeled and analyzed with three-process variables viz., influent COD (3000, 6500 and 10,000mg COD/l), biomass concentration (2000, 4000 and 6000mg VSS/l) and initial alkalinity (200, 1100 and 2000mg CaCO3/l). Experiments were conducted based on a central composite face-centered design (CCFD) and analyzed using response surface methodology (RSM). In order to carry out a comprehensive analysis of the biogas production process, the indicative parameters viz., specific methanogenic activity (SMA), bicarbonate alkalinity produced-to-COD removed ratio, and COD removal were studied as the response. The maximum SMA was modeled to be 0.99g CH4-COD/g VSS d under CODin, initial bicarbonate alkalinity (BA) and biomass concentrations of 10,000mg COD/l, 2000mg CaCO3/l and 2000mg VSS/l, respectively, while the observed value was 1.039g CH4-COD/g VSS d. The maximum COD removal was achieved at the condition when the influent COD was within the range of 4250–5250mg/l and initial BA was more than 1100mg CaCO3/l. Initial BA and CODin played an important role in the production of bicarbonate alkalinity during the digestion process.

  • Response surface methodology (RSM) analysis of organic acid production for Kaolin beneficiation by Aspergillus niger
    E. Aghaie, M. Pazouki, M.R. Hosseini, M. Ranjbar, and F. Ghavipanjeh

    Chemical Engineering Journal, ISSN: 13858947, Volume: 147, Issue: 2-3, Pages: 245-251, Published: 15 April 2009 Elsevier BV
    Abstract In the present investigation, Aspergillus niger isolated from pistachio shell was applied to remove iron impurities from an Iranian kaolin sample. In order to study the effects of initial pH, sucrose and spore concentration on oxalic and citric acid production, and consequently iron dissolution, response surface methodology based on a five-level, three-variable central composite design of experiments was employed. Three models were suggested to predict response values based on the mentioned variables. The most important variables on iron dissolution were initial pH, sucrose and spore concentration, respectively. Also, the highest iron concentration, 311.30 mg/l, was obtained when initial pH was 2, sucrose concentration, 70 g/l, and spore concentration, 35 × 10 7  spore/l, and represented the removal of 67.4% of the total iron contents of the clay.

  • A novel approach for preparation of highly crystalline anatase TiO2 nanopowder from the agglomerates
    A. Hosseinnia, M. Keyanpour-Rad, M. Kazemzad, and M. Pazouki

    Powder Technology, ISSN: 00325910, Volume: 190, Pages: 390-392, Published: 25 March 2009 Elsevier BV
    Abstract A new approach for synthesis of dry and well-shaped anatase titania nanocrystals by different methods of synthesis, like sol–gel and precipitation, is reported. The significance of this new method is the dehydration of titania agglomerates by simple azeotropic distillation to afford uniform and reproducible anatase nanocrystals with particle size

  • Production of organic acids in an immobilized cell reactor using Propionibacterium acidi-propionici
    African Journal of Biotechnology, eISSN: 16845315, Pages: 3332-3338, Published: 17 September 2008

  • Variable optimization for biopulping of agricultural residues by Ceriporiopsis subvermispora
    Kamel Yaghoubi, Mohammad Pazouki, and Seyed Abbas Shojaosadati

    Bioresource Technology, ISSN: 09608524, Pages: 4321-4328, Published: July 2008 Elsevier BV
    Ceriporiopsis subvermispora was used for biochemical pulping of agricultural residues and the results were compared with chemical pulping. Independent variables were screened by Plackett-Burman and optimized by full factorial experimental designs. Biological treatment of rice, wheat and barley straw samples resulted in decrease of the kappa number of these straws by 34%, 21% and 19%, respectively, as compared with controlled samples. The tensile strength and burst factor of hand sheets produced from rice straw were increased by 51% and 33% as compared with the control straws. The tensile strength and burst factor of hand sheets produced from wheat straws were improved by 67% and 36%, these variables for barely straws were 36.7% and 45%, respectively. Although the delignification of wheat and barley straws are not as efficient as chemical process, but the quality of papers produced by biochemical pulping of straws were excellent.

  • Kinetic models of cell growth, substrate utilization and bio-decolorization of distillery wastewater by Aspergillus fumigatus UB260
    African Journal of Biotechnology, eISSN: 16845315, Pages: 1369-1376, Published: 2 May 2008

  • Application of hydrocyclone for removal of yeasts from alcohol fermentations broth
    M. Habibian, M. Pazouki, H. Ghanaie, and K. Abbaspour-Sani

    Chemical Engineering Journal, ISSN: 13858947, Volume: 138, Issue: 1-3, Pages: 30-34, Published: 1 May 2008 Elsevier BV
    Abstract In this research work, the possibility of using hydrocyclones to separate Saccharomyces serevisiae 5209 from a prepared media was studied. The cell separation can be very useful in order to improve the quality of alcohol produced, reduce energy consumption and also reduce the cost of effluent treatments with the hydrocyclone advantage of consuming less energy. A hydrocyclone with 15 mm internal diameter was used for cell separations. A better separation efficiency of 3.84 (gram cell dry weight in: under flow/over flow) was obtained at volumetric flow rate of about 112 cm 3 /s.

  • Screening of microorganisms for decolorization of treated distillery wastewater
    Iranian Journal of Science and Technology, Transaction B: Engineering, ISSN: 10286284, Pages: 53-60, Published: February 2008

  • Modification in synthesis of anatase titanium oxide and comparison of the synthesis methods
    A. Hosseinnia, M. Pazouki, M. Kazemzad, and M. Keyanpour-Rad

    AIP Conference Proceedings, ISSN: 0094243X, eISSN: 15517616, Volume: 929, Pages: 152-156, Published: 2007 AIP
    In this research work, anatase titanium dioxide (TiO2) was prepared by precipitation route using TiCl4 in neutral pH. The dehydration of precipitate was performed by azeotropic extraction using benzene as solvent. After calcinations of product at 600 °C anatase form of titania was confirmed by XRD analysis. Precipitating TiCl4 in pH=3 gives a product of mostly rutile and anatase. The sizes of titania nanoparticles obtained was less than 30 nm as determined by transmission electron microscopy (TEM) studies. In the other method of synthesis, titanium tetra isopropoxide was used in neutral pH. After calcinations of product at 600 °C, most of the titania obtained was brookite and anatase. Increasing the pH by addition of ammonia, Ti (OH)xCl4−x will be formed first, and this increases the concentration of hydroxyl group in solution. In general when pH is higher, the amount of x in Ti(OH)xCl4−x is more. FT‐IR studies before calcination revealed that even in neutral pH this composition is present. Meanwhile the ...

  • Bioleaching of iron from highly contaminated Kaolin clay by Aspergillus niger
    M.R. Hosseini, M. Pazouki, M. Ranjbar, and M. Habibian

    Applied Clay Science, ISSN: 01691317, Issue: 3-4, Pages: 251-257, Published: September 2007 Elsevier BV
    Kaolin is a clay mineral that has a wide application in the industry specially, in paper, ceramic, and porcelain manufacturing. One of the most important factors that affects the value of this raw material is its brightness. Unfortunately, with the iron oxides deposit on mineral particles during kaolin formation, much of this clay has become unusable for industries. So, several chemical methods have been applied in mineral processing plants to reduce these contaminants, but finding a more sustainable approach like biological methods have always attracted a great attention. In this work bioleaching of iron from a highly contaminated kaolin sample was carried out using two different strains of Aspergillus niger, and the effects of strain type, pulp density, and time of clay addition on the iron removal were investigated by employing a 23 full factorial design. Finally, it is concluded that strain type has the most significant effect on the response; also, the highest removal extent was 42.8% that was obtained by using the strain isolated from pistachio shell, and at the pulp density of 20 g/l when the clay was added at the beginning of the experiments.

  • Efficiency of Penicillium chrysogenum PTCC 5037 in reducing low concentration of chromium hexavalent in a chromium electroplating plant wastewater
    M. Pazouki, M. Keyanpour-Rad, Sh. Shafie, and Sh. Shahhoseini

    Bioresource Technology, ISSN: 09608524, Pages: 2116-2122, Published: August 2007 Elsevier BV
    The effectiveness of Penicillium chrysogenum was evaluated for reducing Cr(VI) from the wastewater of a chromium electroplating plant. Statistically-based experimental designs were applied to optimize the condition for reducing Cr(VI) to Cr(III). By applying Plackett-Burman factorial design and central composite design as the optimization step, attempts were made to identify optimal values of the three factors that bringing about maximum microorganism activity and therefore maximum hexavalent chromium(VI) bioreduction. It was found that each gram of P. chrysogenum of dry biomass condition could reduce 66 mg of Cr(VI) to Cr(III) in the wastewater of the chromium electroplating plant.

  • Bioleaching of a high iron content kaolin by Aspergillus niger: The effects of organic acids biosynthesis
    M. Pazouki, M.R. Hosseini, M. Ranjbar, and F. Ghavipanjeh

    Advanced Materials Research, ISSN: 10226680, Volume: 20-21, Pages: 111-114, Published: 2007 Trans Tech Publications Ltd.

  • Optimization of kaolin bioleaching by Aspergillus niger
    M. Ranjbar, E. Aghaie, M.R. Hosseini, M. Pazouki, and F. Ghavipanjeh

    Advanced Materials Research, ISSN: 10226680, Volume: 20-21, Pages: 115-118, Published: 2007 Trans Tech Publications Ltd.

  • Application potential of biohydrometallurgy in the Iranian mining industry
    M. Ranjbar, M. Schaffie, M. Pazouki, R. Ghazi, A. Akbary, S. Zanddevakili, S.A. Seied Baghery, and Z. Manafi

    Advanced Materials Research, ISSN: 10226680, Volume: 20-21, Pages: 38-41, Published: 2007 Trans Tech Publications Ltd.

  • Review of distillery wastewater treatment methods
    Journal of Environmental Studies, ISSN: 10258620, Published: September 2006

  • Application of response surface methodology for optimization of important parameters in decolorizing treated distillery wastewater using Aspergillus fumigatus UB2 60
    Pazouki Mohammad, Hussainnia Azarmidokht, Moztarzadeh Fatollah, and Banifathemi Mahboubeh

    International Biodeterioration and Biodegradation, ISSN: 09648305, Pages: 195-199, Published: June 2006 Elsevier BV
    Distillery wastewater causes many environmental problems and colored substances must be removed from it before discharge into the environment. Decolorization of anaerobically treated distillery wastewater was therefore studied using locally isolated Aspergillus fumigatus. As cultural conditions are very important for the decolorization process, the combined effect of initial maltose concentration, pH and mycelial mass was studied using response surface methodology. A central composite design for the three variables was employed to study the combined effect on decolorization efficiency of distillery wastewater. The optimum initial maltose concentration was found to be 15.13 g/l, the optimum pH was 5.57 and the optimum mycelial mass 2.57 g/l.

  • Electrochemical synthesis of polypyrrole macro-tubes on aluminum substrate
    Ali Eftekhari, Mohammad Harati, and Mohammad Pazouki

    Synthetic Metals, ISSN: 03796779, Volume: 156, Issue: 9-10, Pages: 643-647, Published: 5 May 2006 Elsevier BV
    Abstract A novel structure of conductive polymer films was synthesized by electropolymerization on aluminum substrate under potentiostatic condition at a relatively high applied potential. A thick film of polypyrrole was electrodeposited onto aluminum substrate from an aqueous electrolyte solution of NaNO 3 with pH 12 by applying a constant potential of 2.0 V versus SCE. This polypyrrole film has a good stability with strong adhesion to the substrate surface. However, the morphological structure of the film is different from those previously observed for conductive polymers. Large tubes (ca. 100–200 μm in diameter) are formed, which are spiraled around the cylindrical substrate electrode. Although, the internal channels of these polypyrrole macro-tubes are very wide, the polypyrrole synthesized is sufficiently dense, guaranteeing excellent mechanical stability for this novel morphological structure. On the other hand, such large walls of the macro-tubes have nano-structures.

  • Continuous decolorization of anaerobically digested distillery wastewater
    Jalal Shayegan, Mohammad Pazouki, and Abbas Afshari

    Process Biochemistry, ISSN: 13595113, Issue: 3-4, Pages: 1323-1329, Published: March 2005 Elsevier BV
    Abstract The aim of this research work was to decolorize anaerobically digested (UASB) and aerobically treated distillery wastewater of a process for ethanol production. An Aspergillus species isolated from the soil was used for decolorization. A sequential Plackett–Burman design in three stages was used for optimization of decolorization conditions. Both maximum decolorization and COD reduction under optimized conditions were obtained as 84%. By implementing the optimum values in a pilot scale of an activated sludge system a continuous process for decolorization was conducted. The decolorization efficiency of this system with 48 h retention time was about 75% in a limited period of 4 days. For extension of the decolorization period in a continuous process a sequencing batch reactor was used. This system with a cycle time of about 4.5 h and decolorization efficiency of 70% extended for 12 days which was more than previous reported works. The colour of undiluted wastewater reduced by only 40% with a cycle time of 17.5 h and the system was stable for about 4 days.

  • The relationship between citric acid production and the morphology of Aspergillus niger during fermentation
    Iranian Journal of Science and Technology, Transaction B: Technology, ISSN: 03601307, Pages: 291-297, Published: March 2002

  • Understanding the morphology of fungi
    M. Pazouki and T. Panda

    Bioprocess Engineering, ISSN: 0178515X, Pages: 127-143, Published: 2000 Springer Science and Business Media LLC
    Abstract Filamentous fungi comprise an industrially very important collection of microorganisms, since they are used for the production of a wide variety of products ranging from primary metabolites to secondary metabolites and further on to industrial enzymes (such as proteases, lipases and antibiotics). It is known that fungal morphology is often considered as one of the key parameters in industrial production. For the production of fungal metabolite products, the desired morphology varies from one product to another. Many parameters affect the morphology of fungi during the process of fermentation, among them speed of agitation, specific growth rate, dissolved oxygen, number of spores or conidia per liter of fermentation broth are important and should be considered when higher yield is desired in the process. It is, therefore, of considerable importance to understand the mechanism underlying the morphology of the cell, its growth and product formation by filamentous fungi. Such knowledge may be used in the optimization of the microbial process. Several literatures with various fungi to study their morphology, relating enzyme or product production to the character of the fungi in the study is reviewed. It is also considered that how the process parameters affects the morphology. The aim of this communication is to review the relevant literature to understand the morphology of filamentous fungi.

  • Comparative studies on citric acid production by Aspergillus niger and Candida lipolytica using molasses and glucose
    M. Pazouki, P. A. Felse, J. Sinha, and T. Panda

    Bioprocess Engineering, ISSN: 0178515X, Pages: 353-361, Published: 2000 Springer Science and Business Media LLC
    Abstract Citric acid production by Aspergillus niger NCIM 548 and Candida lipolytica NCIM 3472 has been studied in shake culture using glucose and molasses as carbon sources. Methanol addition (3% v/v) at 40 h of fermentation enhanced the production of citric acid by Aspergillus niger whereas a reduction in citric acid production by Candida lipolytica was observed with addition of methanol. Maximum citric acid concentration of 12 kg/m3 was obtained with Aspergillus niger using molasses in the presence of methanol, while maximum citric acid concentration of 8.4 kg/m3 was obtained with Candida lipolytica using glucose without methanol. It appears that product formation by Aspergillus niger is either non-growth associated or partially growth associated depending on the substrate. Methanol addition changes the nature of product formation in case of Candida lipolytica.

  • Recovery of citric acid - A review
    M. Pazouki and T. Panda

    Bioprocess Engineering, ISSN: 0178515X, Pages: 435-439, Published: 1998 Springer Science and Business Media LLC
    Abstract The requirement of citric acid is increasing every year. Therefore, it is important to have an efficient recovery method following the production of citric acid. At present, most of the manufacturers use the classical method of citric acid recovery which is a precipitation technique using calcium salt followed by filtration and subsequently treated with sulphuric acid. This review focuses on the new developments of recovery of citric acid from the fermentation broth.

  • Bioprocess Optimization - A Challenge
    Journal of Microbiology and Biotechnology, ISSN: 10177825, Pages: 367-372, Published: 1997