Ghasem Najafpour
Biochemical & Chemical Engineering, Noshirvani University of Technology, Babol
[ 1 ] - Composite Multi Wall Carbon Nano Tube Polydimethylsiloxane Membrane Bioreactor for Enhanced Bioethanol Production from Broomcorn Seeds
Broomcorn seed (Sorghum vulgare) was used as raw material for bioethanol production. Optimum conditions were obtained from response surface method. Broomcorn seed flour (45 g/l) was treated by alkaline treatment and dual enzymatic hydrolysis (0.7 g/l of α- amylase and 0.42 g/l of amyloglucosidase). The hydrolyzed total sugar of 25.5 g/L was used in conventional bioethanol production (8.1 g/l) u...
[ 2 ] - Highly Sensitive Amperometric Sensor Based on Gold Nanoparticles Polyaniline Electrochemically Reduced Graphene Oxide Nanocomposite for Detection of Nitric Oxide
A sensitive electrochemical sensor was fabricated for selective detection of nitric oxide (NO) based on electrochemically reduced graphene (ErGO)-polyaniline (PANI)-gold nanoparticles (AuNPs) nanocomposite. It was coated on a gold (Au) electrode through stepwise electrodeposition to form AuNPs-PANI-ErGO/Au electrode. The AuNPs-PANI-rGO nanocomposite was characterized by Field Emission Scanning ...
[ 3 ] - Kinetic Modeling of Enzymatic Hydrolysis of Pretreated Sorghum Bicolor and Rice Husk
In this study, the hydrolysis of pretreated sorghum stem and rice husk was investigated at various initial enzyme concentrations and substrate loadings. The slowdown in enzymatic hydrolysis of lignocellulosic materials with conversion has often been attributed to decreasing the activity of enzyme. A kinetic model was developed and expressed mathematically based on enzyme deactivation for enzyma...
[ 5 ] - Kinetics and Isotherm Studies of the Immobilized Lipase on Chitosan Support
The kinetics and isotherm studies of the immobilized lipase and the mechanism of immobilization on chitosan beads and activated chitosan beads with glutaraldehyde were investigated. The effect of glutaraldehyde on porosity of chitosan was evaluated by FESEM analysis. It was observed that the porosity of the carrier which has activated by glutaraldehyde was substantially increased. The validity ...
[ 6 ] - Growth Kinetic Survey in Direct Biological Sweetening of Natural Gas in Batch Bioreactor: Temperature Studies
The present study is focused on biodesulfurization of natural gas in a batch culture using active microorganisms. The microorganisms used for the removal of hydrogen sulfide were obtained from a hot spring. The experiments were conducted with mixed gas at operating temperatures of 25 to 45°C with a time interval of 5h. Two kinetic models included Logistic and Monod models in a batch culture wer...
[ 7 ] - Formic Acid and Microwave Assisted Extraction of Curcumin from Turmeric (Curcuma longa L.)
Curcumin is a natural bioactive compound originated from the rhizomes of turmeric (Curcuma longa L.). This study was performed to investigate formic acid and microwave assisted extraction of curcumin from turmeric (Curcuma longa L.). In order to enhance the curcumin extraction, different parameters such as particle size, effect of pretreatment with water, radiation intensity and type of solvent...
[ 8 ] - Hydrolysis of Sorghum (Broomcorn) in Diluted Hydrochloric Acid
Effective conversion of lignocellulosic material as renewable energy source has significant reflection on economic and environmental impact. Diluted acid hydrolysis at optimal condition was used to liberate fermentable sugar. The sorghum stalks, the alkali pretreatment of biomass and hydrolysis in diluted hydrochloric acid were investigated. The hydrolysis reaction was carried out in a 5L react...
[ 9 ] - Evaluation of Cell Growth and Substrate Consumption Kinetic of Five Different Lactobacilli in a Submerged Batch Whey Culture for Lactic Acid Production
Cell growth and lactose consumption profile of five Lactobacillus Strains: bulgaricus, casei, lactis, delbrueckii and fermentum has been investigated. Experiments of cell growth and substrate utilization were conducted in batch submerged culture of whey with added lactose and some other growth factors. Fitness assessment of experimental data on the cell growth and lactose consumption by Monod k...
[ 10 ] - A comparison on Lipase Production from Soybean meal and Sugarcane Bagasse in Solid State Fermentation using Rhizopus oryzae
In this study, solid-state fermentation of two types of agricultural residues/products for lipase production in a tray-bioreactor was investigated. Rhizopus oryzae was used as a potential fungus strain and two types of agricultural residues including soybean meal and sugarcane bagasse were utilized as substrate. Fermentation was carried out in two different operational conditions: one with cont...
[ 11 ] - A Two-step Catalytic Production of Biodiesel from Waste Cooking Oil
Waste cooking oil (WCO) was used as a potential feedstock for biodiesel production. High levels of free fatty acids (9.85% w/w) in WCO made it an undesirable substrate for direct transesterification reaction. To solve this issue, a two-step process was implemented in this research. Firstly, esterification reaction was performed in presence of sulfuric acid as a common acid catalyst to reduce th...
[ 12 ] - Comparative Studies on Effect of Pretreatment of Rice Husk for Enzymatic Digestibility and Bioethanol Production
Three common pretreatment processes based on dilute sulfuric acid, dilute sodium hydroxide and heat treatment (autoclaving) followed by enzymatic hydrolysis were evaluated to provide comparative performance data. Among them, the best result was obtained when the pretreatment of rice husk was carried out with 3% of NaOH solution. The pretreatment of rice husk with NaOH substantially increased th...
[ 13 ] - Enhanced Bioethanol Production in Batch Fermentation by Pervaporation Using a PDMS Membrane Bioreactor
The integration of batch fermentation and membrane-based pervaporation process in a membrane bioreactor (MBR) was studied to enhance bioethanol production compared to conventional batch fermentation operated at optimum condition. For this purpose, a laboratory-scale MBR system was designed and fabricated. Dense hydrophobic Polydimethylsiloxane (PDMS) membrane was used for pervaporation. For fer...
[ 14 ] - Lipase Production in Solid State Fermentation Using Aspergillus niger: Response Surface Methodology
Among enzymes, lipases have been widely investigated because of the numerous industrial applications. In this study, optimization of lipase production by Aspergillus niger in solid state fermentation from rice bran as solid substrate was investigated. The optimal conditions with the aid of central composite design (CCD) under response surface methodology (RSM) were obtained. In the analysis of...
[ 15 ] - Phenol Biodegradation Kinetics in the Presence of Supplimentary Substrate
Biodegradation of phenol in the presence of glucose as a supplementary substrate was investigated with mixed microbial consortium isolated from waste effluent of coke-steel factory. Batch experiments were carried out at room temperature and pH value of 7. Initial phenol and glucose concentrations were in the range of 25-1000 mg/l and 500-3000 mg/l, respectively. In a dual substrates system the ...
[ 16 ] - Environmental Impact of Fossil Fuel Utilization in Neka Thermal Power Plant
Carbon dioxide causes green house effect and has been considered as a pollutant source forsafe environment. Since combustion of fossil fuel may create tremendous amount of carbon dioxide,detecting any pollutant sources would be important to eliminate the origin of pollution sources.Evaluation of smoke dispersion generated by the power plant utilizing fossil fuel is the objective of thispaper. T...
[ 17 ] - Dairy Wastewater Treatment using Three-Stage Rotating Biological Contactor (NRBC)
Dairy wastewater is enriched in organic matter (about 45-72 g/l, COD) and also contains biodegradable carbohydrates. A three-stage system, NRBC was fabricated as a bench scale unit for lab experiments, to remove organic carbon from the whey. The fabricated NRBC had several advantages, such as quick start-up, high biomass concentration and was additionally able to handle high organic loading rat...
[ 18 ] - Recovery of Methyl Acetoacetate from Antibiotic Production Plant\'s Waste Streams (TECHNICAL NOTE)
Chemical recovery of methyl acetoacetate from the amoxicillin plant’s waste stream was investigated. In process of amoxicillin production for activation of amoxicillin molecule, hydrolysis takes place at final stage. As a result methyl acetoacetate is formed. Liquid-liquid extraction was employed for the recovery of methyl acetoacetate from the waste stream. Diluted alkaline solution was used a...
[ 19 ] - Acid Hydrolysis of Pretreated Palm Oil Lignocellulosic Wastes
Palm oil solid wastes consist of cellulose, hemicellulose and lignin. In this study, a single stage of acid hydrolysis process of palm oil empty fruit bunch (EFB) for production of fermentable sugar was carried out under moderate temperature (45°C) and ambient pressure. The effect of four different process variables such as solid size, HCl concentration, solid percentage and temperature were in...
[ 20 ] - Pretreated Palm Oil Mill Effluent (POME) Digestion in an Up-Flow Anaerobic Sludge Fixed Film Bioreactor: a Comparative Study
An up-flow anaerobic sludge fixed film (UASFF) bioreactor was used to treat the pretreated palm oil mill effluent (POME). In physical pretreatment, POME was pre-settled for 2 h and the supernatant was fed into the reactor. In chemical pretreatment, optimum dosages of cationic and anionic polymers were used. Experiments of pretreated POME digestion were conducted based on a central composite fac...
[ 21 ] - Dynamic Model For Production of Biohydrogen Via Water- Gas Shift Reaction (RESEARCH NOTE)
In design of anaerobic bioreactor, rate equation is commonly used. Mathematical model was developed at steady state condition, to project concentration of gaseous substrate and product in biological oxidation of carbon monoxide with water to produce hydrogen and carbon dioxide. The concept of bioconversion was based on transport of CO from gas phase to liquid phase, as the CO consumption was in...
[ 22 ] - Citronellyl Butyrate Synthesis in Non-Conventional Media Using Packed-Bed Immobilized Candida Rugosa Lipase Reactor
The synthesis of citronellyl butyrate by direct esterification reaction catalyzed by immobilized lipase from Candida rugosa was studied in a continuous packed bed reactor using n-hexane as organic solvent. Parameters such as residence time, temperature, and pH were examined. The optimum conversion was obtained at a flow rate of 1 ml/min (residence time 8 min), temperature of 50 °C, and pH 7.5. ...
[ 23 ] - Performance of Biological hydrogen Production Process from Synthesis Gas, Mass Transfer in Batch and Continuous Bioreactors
Biological hydrogen production by anaerobic bacterium, Rhodospirillum rubrum was studied in batch and continuous bioreactors using synthesis gas (CO) as substrate. The systems were operated at ambient temperature and pressure. Correlations available in the literature were used to estimate the gas-liquid mass transfer coefficients (KLa) in batch reactor. Based on experimental results for the con...
[ 24 ] - Microbial Desulfurization of Malaysian Coal in Batch Process using Mixed Culture (RESEARCH NOTE)
Biodesulfurization of coal has been carried out in batch culture of single strain and mixed culture of sulfur oxidizing bacteria. The pure cultures of Thiobacillus thiooxidans and Thiobacillus ferrooxidans utilized inorganic sulfur content of Malaysian coal. The chemolithotroph bacteria were able to grow on coal and metabolize the coal's sulfur content. The batch cultures of coal with 3-5 perce...
[ 25 ] - Solubility of Hydrogen Sulfid and Sulfur Dioxide in Triethylen Glycol, Tetra Ethylene Clycol and Diethanol (TECHNICAL NOTE). AMINE SOLUTION
Natural gas sweetening is an important process which is used for treatment of sour gases. The measurement of solubility is also considered in most sweetening processes such as that of Townsend process. Therefore, experimental measurements would be helpful to determine the equilibrium data under actual equilibrium conditions for the gas treatment plants. In this research solubility of hydrogen s...
[ 26 ] - Bioreactor Scale-up for Water-Gas Shift Reaction
A scale-up study has been performed with three different size reactors to establish the optimum operating conditions for the hydrogen production from synthesis gas by biological water-gas shift reaction using the photosynthetic bacterium Rhodosprilliunt rubrum. Optimum medium composition and operating conditions previously determined in a bench scale 1.25 L continuous stirred tank reactor (CSTR...