Journal of Applied Research in Chemistry
Year:2017 | Volume:11 | Issue:1|Papers Count:10

In the present research, different economical treatment methods which are suitable for water recycling and dye removal of wastewaters have been studied according to the water resources limitation. In recent years, application of Geraphene as a new adsorbent and photocatalytic material has been developed among the other treatment processes. Graphene and functionalized graphene are important candidates due to their unique properties. They are considered as good adsorbents for water purification due to their large scale production with low cost, two dimensional layer structure, large surface area, pore volume, and the presence of functional groups on the surface of graphene oxide and possibility for the selective absorption of pollutants. Graphene nanocomposite prevents nanoparticles from agglomeration and enables the good dispersion of these materials. As a result, volume pores and surface area of nano adsorbents are protected. In addition, graphene oxide and its derivatives can be effectively removed by selective absorption of pollutants. The functional groups on graphene provide the necessary substrate for heavy metal complexation. On the other hand, graphene composites have an important role in enhancement of photocatalytic process and mineralization due to their flat structure, transparency, high carrier mobility, conductivity, reduction of recombination rate of photoinduced electron hole pairs, and the possibility of π-π interactions of photocatalysts and organic materials. For this purpose, some researches on the ability of Geraphen and functionalized geraphen on the colored wastewater treatment have been studied and comparisons have been made with the other photocatalytic processes.

In this work, four-component, one-pot synthesis of polyhydroquinolines using aldehyde derivatives, β-ketoester, dimedone, and ammonium acetate in presence of tannic acid as a inexpensive, mild, and eco-friendly catalyst is discussed. Operational simplicity, high yield, short reaction time, simple work up without need to column chromatography and use of mild and environmental friendliness conditions are some of benefits of the present method in synthesis of this biologically compounds.

Due to the destructive effects of the Carbon block in the rubber compounds as major filler on the environment and the increasing of the fossil fuel consumption in the constructed tires with this filler, in this research, we tried to apply an alternative inorganic filler with silicate base. It was extracted from the mines of the Iran and was replaced with 30% of Carbon block.Particle size was measured by Dynamic light scattering method. To investigate the functional groups of inorganic filler IR techniques were used. The results of this investigation demonstrated that rheological properties of the compounds reinforced by inorganic filler with silicate base have proper conditions compared to the control compound. However, a significant point is obtained from DMTA graph in which the noticeable reduction of Tand at 70oC is related to compound filled with inorganic filler compared to control compound (filler with C.B). This is an indication of the decreasing heat accumulation at compound with lower tand (blend reinforced with silicate), which means that constructed tires with this filler will consume the less fuel for lower heat resistance.

In this study nanocellulose hydrogel was prepared by chemical (acid hydrolysis) and mechanical treatment (ultrasonic waves) of cotton pulp. Different parameters incluging type and concentration of acid, hydrolysis time, and power of ultrasonic treatment were investigated.Nanocellulose aerogel was prepared using solvent exchange method followed freeze drying process. The effects of parameters including hydrogel concentration, solvent type, and solvent to hydrogel ratio were studied. Spectral properties of nanocellulose were characterized using FT-IR, XRD, SEM and TEM. Their zeta potential and degree of polymerization were analyzed. The results showed that the process yield at optimum condition was 62.1%. In FE- SEM micrograph, network structure of nanocellulose fibers can be observed. In TEM micrograph, there is rodshaped nanocrystalline cellulose with a diameter of 25-50 nm and a length of 100-400 nm. Its degree of polymerization was 81.54 and it had good thermal stability. Specific surface area of nanocellulose aerogel prepared in optimum condition was 92.0 m2/g. The low thermal conductivity of nanocellulose aerogel, 25 mW/m K, showed that it could be used as high efficient thermal nanoinsulator.

In this study, adsorption of manganese (II) from aqueous solution as environmental pollutants has been studied. The mixing ratio of 30 to 70 wheat bran to Japanese medlar core shell is used as adsorbent. This paper incorporates the effects of adsorbent weight, pH, contact time, and temperature. The optimal weight of adsorbent, pH, contact time, and temperature were obtained as 1 g, 6.5, 180 minutes, and 293.15 K, respectively. The adsorption process fitted the Temkin model with a correlation coefficient of 1. The thermodynamic parameters, including change in standard Gibbs free energy (DGo), enthalpy (DHo), and entropy (DSo) have been calculated. FT-IR analysis was performed to identify the functional groups on the adsorbent surface. The morphology of surface has been investigated using scanning electron microscopy.

Mg1-xZrxNiO3 perovskite nanocatalysts were synthesized by citrate sol-gel method.The synthesized samples were characterized by using X-ray diffraction (XRD), temperature programmed reduction (TPR), and inductively coupled plasma (ICP) techniques. Surface areas of the samples were measured by BET method. Morphology study of the nanocatalysts was performed using scanning and transmission electron microscopy (SEM and TEM). The XRD patterns of the samples showed that Zr doping level was 0.4 for Mg1-xZrxNiO3. The SEM images showed that the synthesized particles were in nanoscale. The TPR analysis revealed that by increasing the amount of Zr up to x=0.3 in the prepared samples, the hydrogen consumption was increased and reduction process became easy. The catalytic activity of the nanocatalysts was investigated in dry reforming of methane (DRM) with CO2 and the obtained results indicated that in the presence of synthesized nanocatalysts, decreasing trend of H2/CO ratio was as below: Mg0.7Zr0.3NiO3>Mg0.9Zr0.1NiO3>MgNiO3

The objective of this research is investigation and optimization of calcination time and temperature of manganese oxide catalyst supported on multiwalled carbon nanotubes for selective catalytic reduction of nitrogen oxides by ammonia. The catalysts were prepared by the incipient wetness impregnation method and calcined at 300-600oC for 2-12h in an atmosphere of Argon.XRD, Raman, H2-TPR, and XPS analyzes showed that calcination temperature is an effective factor by changing the oxidation state of Manganese, so that the catalyst calcined at 300oC has the maximum activity with MnO2 as a dominant phase of manganese. Also, the presence of nitrate species reminded from decomposition of manganese nitrate at moderate calcination temperature (300oC) is beneficial to NH3- low temperature selective catalytic reduction of NOx by increasing catalyst acidity and NH3 adsorption on the surface of the catalyst. The effect of increasing the calcination time from 2 to 6h on crystallinity, surface area, and oxidation state of active site was negligible. However, with refer to the H2-TPR analyze, increasing the calcination time to 12h decreased NOx conversion a little, an effect that could be attributed to the reduction of residual nitrate species. Finally, the 12wt% manganese oxide catalyst calcined at 300oC for 3h had the best activity and N2 selectivity of 97% and 99.5%, respectively.

In this study, a simple and fast method was developed for ofloxacin determination.Ofloxacin is an antibiotic that is used to treat bacterial infections. Ultrasound-assisted emulsification microextraction (USAEME) based on applying heavy density organic solvent followed by high performance liquid chromatography (HPLC) was used for ofloxacin determination. For this purpose, 150ml chloroform as extraction solvent was slowly injected into the centrifuge glass vial containing 10ml aqueous sample located inside the ultrasonic water bath. The formed emulsion was centrifuged at 5000 rpm and 20ml of separated organic solvent containing extraction ofloxacin was injected into the HPLC system equipped with a UV/Vis detector at 290 nm. The influences of different parameters affecting the USAEME procedure were evaluated to optimize the efficiency of the microextraction process. Under the optimum extraction conditions, the calibration carve was linear in range of 10- 1000mg l-1. The limit of detection (LOD), limit of quantification (LOQ), and preconcentration factor in water sample were obtained 7, 23mg l-1 and 27, respectively.

In this study, a sensitive and economical method is suggested for the rapid determination of total naphthalene sulfonates (NSs) in seawater samples. These compounds were first converted to ion pairs by reaction with tetrabutylammonium. Subsequently, they were extracted and pre-concentrated employing in-syringe dispersive liquid-liquid microextraction technique using a mixture of 250ml of toluene as extracting and 500ml of methanol as dispersion solvents. Their concentrations were determined spectrophotometerically in micro-cuvettes at 230 nm. Parameters affecting extraction efficiency including pH, type and volume of extraction and disperser solvents, and amount of tetrabutylammonium (ion pair reagent), were investigated and optimized. Under the optimum conditions, the enrichment factor (for 1-Naphthalene Sulfonic acid) was 142 folds.The linearity of the technique was in the range of 1-75mg.l-1 with a detection limit of 0.30mg.l-1 for the same compound. The relative recoveries of total NSs from seawater samples at spiking levels of 20mg.l-1 were between 88.0-98.5%. The proposed method was successfully applied for the determination of total NSs in seawater of Chabahar Bay.

In the present work, an electrochemical sensor prepared for D-Penicillamine by modified carbon paste electrode with Acetylferrocene. For the first time, electrochemical behaviour of D-Pencillamine at the surface of Acetylferrocene modified carbon paste electrode has been investigated using cyclic voltammetry (CV) and chronoamperometric method. The experimental results suggest that the modified electrode exhibits electrocatalytic effect on the oxidation of D-pencillamine resulting in a marked enhancement of the anodic peak current response. Under the optimal conditions, the anodic peak current was linearly dependent on the concentration of D-penicillamine in the range of 0.07 to 1 mM and 0.002 to 0.022 mM with CV and amperometric method, respectively. The detection limits (3d) were also estimated to be 0.05 and 0.001 mM. Some kinetic parameters, such as the catalytic rate constant (k=2.88 cm3 mol-1 s-1) of penicillamine, were calculated.Simplicity, cheapness, high sensitivity, good reproducibility of the electrodes with the low detection limit can be found including the outstanding properties of this electrode.