ali arasteh nodeh

Urea (NH2CONH2) is very important for the agriculture industry as a nitrogen-rich fertilizer. Urea synthesizes from ammonia (NH3) and carbon dioxide (CO2) at 170 - 180˚C and 143 kg/cm3. This study aims to reduce the amount of urea dust from the flue gas emitted from the Urea Prilling Tower of Khorasan Petrochemical Company. Since the conversion process of molten urea to urea seeds produce much dust, a large amount of environmental pollution caused by this industry can be prevented by examining various factors in dust production in this plant. Thus, the project was divided and implemented into six general phases (Six Sigma project), including problem definition and study phase, measurement and estimation of time and cost required, preliminary analysis, design, and implementation (DMAIC methodology). After implementing the plan, a significant reduction in urea emissions was observed, about 38%. Therefore, the results show that Six Sigma is a useful tool that can accurately predict the removal of urea dust from flue gases.

Due to the fact that the wastewater of ceramic factories have higher TDS and turbidity, Poly propylene fumarate (PPF) membranes seems to be suitable for the treatment of this type of wastewater due to their good mechanical performance, adjustable biodegradability and easy production. However, the main disadvantage of the PPF in membrane separation related to hydrophobicity property of it which leads to a low membrane flux and is easily susceptible for fouling. Presence of oxygenated functional groups such as hydroxyl, epoxy, and carboxyl in GO causes the modified membranes have high effective flux and better antifouling property. One of main problem associated   with preparation of membranes containing GO is possibly related to the more homogenous dispersion of GO into the polymer matrix. The presence of Pluronic F-68 can solve this problem.
Material and

In this work, in order to improve the hydrophilic and morphological properties of PPF membrane, the graphene oxide that has been modified by Pluronic F-68 was added in to the membrane. These membranes were prepared with VIPS method.  The effects of the modified additive concentrations and vapor exposure times on hydrophilicity and permeation flux of the PPF membranes in mentioned wastewater treatment were investigated.

Increasing GO/Pluronic F-68 loading from 0 wt. % to 4 wt. %, the hydrophilicity level is increased and the contact angle is decreased by increasing the exposure time up to 30 min due to the high poros ity of membranes than others. The modificated membranes by Pluronic F-68 /GO present higher pure water permeability in comparison with the neat PPF mem brane.
Discussion and

These membranes have higher pure water permeability in comparison with the neat PPF mem brane. The membrane modified with 4wt. % of GO/Pluronic F-68 (Exposure time of 20 min) has high ability in reduction of wastewater pollution indices in comparison with others.

In this study, a thermodynamic behavior of the quaternary system of (Poly propylene fumarate/ (Graphene oxide/ Pluronic F-68))/2-pyrrolidone (2P)/water was evaluated. The binodal and spinodal curves plotted using by Flory–Huggins theory and compared with experimental data. The results showed that at low value of binary parameter, a high interaction is existed between two components in ternary system. The ternary system at positive ternary interaction parameter (g123) indicates a small miscible region and small changes in water content of the polymer-rich phase. At the negative values of g123, there is a high miscibility in ternary system. In quaternary system, when g1234 is positive, the binodal curve shifts to the (polymer/additive)/ solvent axis. The membrane formation depends on the thermodynamic behavior of casting solution. By increasing the additive in casting solution up to 4wt.%, the de-mixing process was accelerated. Hence, a membrane was formed with high porosity. When additive content was increased to more than 4 wt%, dynamic viscosity of casting solution was responsible to the phase separation rate decreasing.

Surfactants are widely used to improve membrane processes due to their ability to trap toxic, organic compounds and heavy metals in industrial wastewater treatment. In this study, the micellar-enhanced ultrafiltration process (MEUF) was used to improve the efficiency of ultrafiltration process to reduce COD, TDS, and turbidity and promote membrane permeate flux in dairy wastewater treatment. The influence of three operating parameters: SDS concentration, transmembrane pressure and pH with their interactions effects were evaluated using surface response methodology (RSM) in box-behnken design. The results showed that the concentration of anionic surface active agent as one of the most influential factors due to the formation of concentration polarization layer and increase in the number of micelles had a negative effect on flux, but had a positive effect on the elimination of the contamination indexes. Also, due to the compression of micelles, the amount of pollutant removal was reduced at high operational pressures. In addition, increasing pH improved the removal of COD, TDS, and turbidity.

The present study has focused on the effect of stirring to produce ferric saccharide capsules with alginate coating applying the coacervation method so that we can obtain the best capsules for fortification of hydrated and dehydrated food products. At first, three methods including stirrer, ultra-sonic and sonic bath were compared in order to select the best way of stirring. The experiments results showed that turning was provided by the stirrer method resulted in capsulation with spherical morphology and uniform distribution of surface. In this case the other factors such as the alginate concentration and calcium salt concentration were investigated. After studying the various conditions, it is suggested that the best Capsules were formed in alginate 3% at 500 rpm with concentration of calcium chloride salt 1M. The resulted capsules by this method had a high efficiency and were more stable in hydrated and dehydrated food ingredients network for a long time.

The Photocatalytic degradation of chemical pollutants such as dyes, especially by Nano catalysts is an effective method to protect the environment and water resources. In this study, through Forced Hydrolysis and Reflux Condensation (FHRC) method the nanospherical α-Fe2O3 particles were synthesized and supported on the surface of silica sand by Solid-State Dispersion (SSD) method with the average crystallite size of 27.5 nm. The characterization of catalyst and catalyst support was done using FTIR spectroscopy, SEM images, XRD patterns and BET surface area.In this paper, α-Fe2O3/SiO2 nano photocatalyst was used for the removal of methyl red (MR) under ultraviolet (UV) light. After running different tests, the effective parameters such as the concentration of MR, pH, and mass of catalyst on pollutant degradation were optimized by single-variable method. The results showed that the optimum conditions for achieving 98.46 % of degradation were pH at 5, initial concentration of MR at 10 mg/l, and 2.0 g of α-Fe2O3/SiO2 nano photo catalyst.

Enaminones are chemical compounds consisting of an amino group (−N=) linked through a C=C to a C=O group. In this research, four various enaminone structures were theoretically optimized. These enaminone structures have been studied for substituent effect on hydrogen bond, method and basic set effects on the geometrical parameters, vibrational frequencies and etc. Drawing molecular structures and computer calculations were performed with Gauss view (5.0) and Gaussian (09) softwares, respectively. The utilized methods in the paper were the HF and DFT and of DFT methods of basic functions B3LYP and B3P86. Also Basis sets of 6-311G, 6-311G*, 6-311G**, 6-311+G** and 6-311++G** have been utilized. Generally the results of computer calculations and comparing them with experimental equivalents indicate that theoretical procedures could well be helpful and effective in enaminone studies and offer reasonable and well results. Enaminone structure was studied for tautomerism and it was revealed that Ketamine form is more stable than Enolimine form

Microencapsulation is a process in which solid, liquid or gas components are covered with a septum.The present study has focused on the effect of stirring to produce ferric saccharide capsules withalginate coating applying the coacervation method so that we can obtain the best capsules forfortification of hydrated and dehydrated food products. At first, three methods, including stirrer,ultra-sonic and sonic bath were compared in order to select the best way of stirring. The experimentresults showed that turning was provided by the stirrer method resulted in capsulation with sphericalmorphology and uniform distribution of surface. In this case the other factors such as the alginateconcentration and calcium salt concentration were investigated. After studying the various conditions,it is suggested that the best Capsules were formed in alginate 3% at 500 rpm with concentration ofcalcium chloride salt 1M. The resulted capsules by this method had a high efficiency and were morestable in hydrated and dehydrated food ingredients network for a long time.

Contamination of water resources by pesticide toxins is considered as one of environmental issues which is because of plant pest diversity and subsequently use of various toxicants. In previous decades all over the world, the usage of organophosphorus toxins in order to preservation of agriculture products expanded. In Gilan province (Iran) there are numerous agriculture lands and gardens which are sprayed intermittently and since drinking water of the region residents is rather supplied by underground waters, then penetration of toxicants into the wells is possible. For this reason pesticide toxicants use could be a treat for drinking water supplying resources of this state. In the paper, samples of water from ten wells were collected and for measuring the quantities of toxicants, experiments were carried out during 4 seasons of year. Toxicant residues in samples were analyzed according to Gas Chromatography–Electron Capture Detector (GC-ECD) method. Due to phosphorous toxicant analyze results; it is revealed that in some cases precipitation amount has a great effect on toxicant concentration inside well water because of leaching higher layers. Also it is indicated that clay presence in soil due to toxicant holding and rain or flood occurrence cause to decrease and increase toxicant leak into the underground water respectively. Finally in order to Hinosan toxicant removal from water resources, active carbon has been utilized. The results indicated that adsorption by active carbon was of Langmuir type and this adsorbent effective cause to eliminate Hinosan toxin from water resources.

In this study, the dilute acid Hydrolysis of saffron waste as a lignocellulose biomass for fermentable sugar production as a green fuel is investigated. Saffron plant waste was collected, washed with distilled water, dried by being exposed to air and sunlight, milled by a disk mill up to 50 micrometers and kept in plastic at room temperature. The prepared biomass was heated in a specified acidic solution for a predetermined time period in the autoclave. The influences of 3 major parameters including temperature, acid concentration and time on the produced fermentable sugar is investigated by the response surface method. According to previous studies, the levels for pretreatment were: temperature (116, 124, 132, and 140oC), process time (20, 30, 40, and 50 minute and sulfuric acid concentration (0, 1, 2, and 3%). To determine the type and quantity of products, the filtered solution was analyzed by HPLC and the results (glucose, xylose and furfural) were modeled by a quadratic equation. This model showed that glucose concentration was influenced by the quadratic power of acid concentration and time while xylose concentration was influenced by time and furfural depends on time alone. It may be concluded that high acid concentration, low temperature and medium time could produce maximum products (glucose and xylose) with minimum inhibitor (furfural).

Tableware is a white and dense body that produced by three basic raw materials like silica, feldspar and kaolin. Each of them has n effect on module of rapture, translucency and whiteness. Translucency imply to passing light through body and best way to achieve it, is producing a fused phase without any crystal and porosity that have different diffraction factor. To design a best composition, we should mix this material to reach essential properties for producing tableware in production line as biscuit, fired and green module of rapture, shrinkage and resistance to deformation besides the other properties we said. In this paper to achieve the highest Translucency we used Marand Washed kaolin, Mallayer Silica and Hamedan Feldspar and fixed clay content at 65% and changed silica and feldspar content then provided different composition and measure all properties by physical experiment, Scand picture(SEM), X-ray diffraction. Colorimeter and light transition measurement Results show in 20% silica and 15% feldspar composition we can have a fused phase with minimum crystal phase and porosity that lead to maximum light transition besides other essential properties.