Journal of Applied Research in Chemistry
Year:2016 | Volume:10 | Issue:2|Papers Count:9

In this work, a new thiazol derivative, N2, N6-di (thiazol-2-yl) pyridine-2, 6-dicarboxamide (DPD), was synthesized via reaction of 2-aminothiazole and 2, 6- pyridinedicarboxylic acid in n-methylpyrrolidine. The synthesized DPD was characterized with different techniques such as nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR), and elemental analysis. After structural characterization, DPD was successfully used for removal of Cd2+and Zn2+ions from industrial wastes and the effects of several parameters such as pH, possible interfering ions, contact time, concentration of target ions, background electrolytes, and temperature on the adsorption of Cd2+ and Zn2+ ions were investigated. The maximum adsorption capacities of Cd2+ and Zn2+ were found to be 128.21 and 90.09 mg.g-1, respectively. The required times for quantitative removal of Cd2+ and Zn2+ were 30 and 45 min, respectively. In addition, the equilibrium isotherms for the adsorption Cd2+ and Zn2+ ions on the DPD surface were analyzed using the Langmuir and Freundlich models. The obtained results show that adsorption isotherm data for Cd2+ and Zn2+ ions are consistently better with Langmuir than Freundlich isotherms. Appropriate characteristics of the DPD such as high adsorption capacity, stability, reusability, and easy synthesis make it suitable adsorbent for removal of Cd2+ and Zn2+ ions from industrial wastes.

In this paper, a new modeling method based on three-layer artificial neural network (ANN) techniques is described which can predict the extraction efficiency of zinc ions by means of molecularly imprinted polymer. Input variables of the model were pH of the solution, absorption and desorption time, amount of ligand, volume of sample solution, and amount of polymer while the output was extraction yield of zinc ions. The mean squared error and correlation coefficient between the experimental data and the ANN predictions were determined as 0.0001 and 0.99923 for training, 0.0010 and 0.99373 for validation, and 0.0031 and 0.99178 for testing data sets. Under the optimum conditions, the linear range found to be between 20-1000 mg.l-1 with the detection limit of 2.9 mg.l-1. The relative standard deviation was calculated to be below 9.2%. The method was successfully applied to the pre-concentration and determination of Zn in a few real samples.

For sustainable development and environmental protection, it is essential to find a comprehensive and practical approach for treating and managing the effluent stream produced from processing crude oil in desalination plants. In this research, the feasibility of using membrane technology to filter and treat that wastewater to meet the standard for injecting into disposal wells is studied. To do such a task, a semi-industrial pilot plant equipped with microfilter membrane modules and a combination of UF membrane modules made of polypropylene membranes is utilized. Moreover, the feed of the pilot is obtained from the waste water tank of sour crude Bangestan located at is Karoun (2) oil and gas company. Then, the removal of impurities at the feed flow rate of 40 and 20 lit/min during micro-filtration, ultra-filtration, and the combination of micro and ultrafiltration methods are investigated. Results show that by using the latter method with the feed flow rate of 40 lit/min, the quality of the produced water is closer to the obligatory environmental and operational standards.

The present work focused on the investigation of hydrogen generation through the ethanol auto-thermal reforming (ATR) with ZrO2 over gama aluminum oxide catalysts. Monodispered colloidal zirconium oxide was synthesized by water-in-oil microemulsion using ZrOCl2.8H2O and NH4OH. ZrO2/g-Al2O3 catalysts were prepared by dispersing highly stable ZrO2 nanoparticles on γ-Alumina by mechanical stirring. The effect of the particle size was studied by varying the molar ratio of Zr: Al. Catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. The results obtained from temperature programmed reduction (TPR) technique, confirmed the uniformity of ZrO2 dispersion over the carrier. The particle size were distributed in 12-27 nm range. Also, in this research, auto-thermal reforming of ethanol was conducted in a quartz fixed bed reactor at atmospheric pressure. The exiting gases of the reactor were analyzed with on line gas chromatography. Among the catalysts tested, Zr: Al (1.0: 3.0) molar ratio showed to be the best catalytic performance in hydrogen production by ATR.

Dissolved carbon dioxide flotation after emulsification micro extraction (DCF-EME) technique coupled with high-performance liquid chromatography. was applied for preconcentartion and determination of Diuron in surface water samples. DCF-EME method is based on the rapid and simple phase separation of low density organic solvent from the aqueous phase via introducing HCl 2 M into the saturated NaHCO3 sample solution containing analytes. In situ generation of carbon dioxide (CO2) bobbles intensified by ultrasound radiation result in the collection of dispersed extraction solvent on the surface of aqueous sample in the capillary part of the designed extraction cell.Under the optimal conditions, the calibration curves were linear in the range of 6 to 5000 ng.l-1 with the correlation coefficients (R2) of 0.999 in water sample. The limits of detections (LOD) and limits of quantifications (LOQ) were 6 and 20, respectively. The preconcentration factor for the mentioned method was 338. The applicability of the proposed method was evaluated by the extraction and determination of the analytes in surface water samples.

A highly-sensitive glucose biosensor was fabricated by immobilization of glucose oxidase (GOX), onto a poly (4-aminothiophenol) /multi-walled carbon nanotube/glassy carbon electrode (poly (4-ATP) /MWCNT/GCE). Cyclic voltammetry was used for both the electrochemical synthesis of poly- (2, 6-DP) on the surface of a MWCNT-modified GC electrode, and characterization of the polymers deposited on the GC electrode. The synergistic effect of the high active surface area of both the conducting polymers, i.e., poly- (4-ATP) and MWCNT gave rise to a remarkable improvement in the electro catalytic properties of the biosensor. The transfer coefficient (α), heterogeneous electron transfer rate constant, and Michaelis–Menten constant were calculated to be 0.47, 3.2 s-1, and 49.82 mM at pH 7.4, respectively. The GOx/poly (4-ATP) / MWCNT/GC electrode exhibited a linear response to glucose in the concentration ranging from 1 to 450 mM with a correlation coefficient of 0.996, sensitivity of 0.021 mAmM-1cm-2, which could make it a promising bioelectrode for precise detection of glucose in the biological samples.

In this paper, the effect of direct hydrothermal method on the synthesis of Cr (8%) /MCM-41 nanocatalyst was investigated in order to use it in ethane dehydrogenation to ethylene with CO2, and the results were compared with impregnation method. The physicochemical properties of the nanocatalysts were characterized by XRD, BET, FESEM, FT-IR, and EDX analysis. XRD analysis confirmed formation of MCM-41 and Cr2O3 crystalline phases. FESEM results demonstrated uniform morphology, small nanoparticles, and narrow distribution of particle size. EDX analysis illustrated homogenous dispersion of Cr species as a result of employing one-pot hydrothermal method. FT-IR results confirmed MCM-41 formation. Based on the characterization results, one-pot hydrothermal method endowed the sample with more uniform, tunable, and smaller nano particle size, leading to modified adsorption properties; and more homogenous dispersion compared to impregnation method. The catalytic experiments were conducted under atmospheric pressure and in the temperature range of 550-700°C with reactant stream consisting of 10% ethane, 50% carbon dioxide and 40% nitrogen. It was found that the direct synthesized nanocatalyst exhibits a reasonable and stable catalytic activity even after 10 hours on-stream operation, giving 42.3 and 97% ethylene yield and selectivity at 700°C, respectively. It exhibits better ethylene selectivity and comparable yield with that of impregnation method.

In recent years, severed environmental regulations have been established for the deep desulfurization of fuel. Selective adsorption of organosulfurs is one of the most applied techniques for the desulfurization of different fuel. The most important advantage of this method is applicability this method in atmospheric pressure and temperature as a result of reducing operational cost in refineries. In this study, Raney Nickel was used as a suitable catalyst for chemical adsorption of some organosulfurs (such as mercaptan, thiophenes, sulfides, disulfides) in several gas condensates. In this research, the Raney Nickel was supplied from three different companies. The prepared alloys were initially characterized by elemental analysis, BET and XRD spectroscopy. Under the same conditions, the Raney Nickel catalysts were prepared from their original alloys by caustic elution method. In order to study physicochemical and adsorption properties of the adsorbents, the different experiments such as XRD, BET, SEM were established. The effect of sample size of the adsorbents in the sulfur adsorption process was also investigated.