In this work, new method for removal of sulfur dioxide from combustion gases was studied. Al2O3, Cu-Al2O3, and Mo-Al2O3 were examined as the catalysts for reduction of sulfur dioxide to elemental sulfur with methane and their performances were compared in terms of SO2 conversion and selectivity. The effects of temperature, SO2/CH4 molar ratio, and reaction time on SO2 reduction were studied. The operating temperature range was 550– 800 ° C and it was observed that the reaction is strongly temperature dependent. Performance of the catalyst extremely enhanced when molybdenum and copper were added as promoters, and the Al2O3-Cu (10%) catalyst showed the best performance between of all the catalysts in terms of SO2 conversion and selectivity. For the Al2O3-Co(10%) as the best catalyst, the conversion of 99. 5% and selectivity more than 99. 5% were achieved at 750 ° C. Effect of molar feed ratio of SO2/CH4= 3-1 was studied and stoichiometric feed ratio showed the best performance. Also, investigation of reaction time for catalysts showed a good long-term stability for SO2 reduction with methane in 5 hours.

Bismuth vanadate is one of the most widely used semiconductors for photoelectrochemical water splitting using sunlight due to its activity in the presence of visible light, stability, and cost-effectiveness. In addition to having a suitable band gap, this semiconductor has disadvantages such as high electron-hole recombination. In this research, with the aim of reducing electron-hole recombination and increasing the efficiency of bismuth vanadate photoelectrodes, templated mesoporous titanium dioxide prepared by P123, F127, and Brij 58 copolymers were used. The effect of three and two-block copolymers on the properties of prepared mesoporous synthesized titanium dioxide and their effect on the bismuth vanadate photoelectrode was investigated by FE-SEM, XRD, UV-vis, and BET analyses. These copolymers changed the porosity by creating cavities of different sizes, resulting in different loads of bismuth vanadate on titanium dioxide. To evaluate the photoelectrochemical results, LSV and electrochemical impedance spectroscopy were performed on the photoelectrodes. Absorption in the visible region showed an increase in current at a potential of 1.23V vs RHE and a low charge transfer resistance in Meso TiO2 / BiVO4 samples. The results showed that the templated mesoporous titanium dioxide increases the activity of bismuth vanadate up to 2.5 times.

Background: Refineries produce about four percent of the global carbon dioxide emissions, close to one billion tons per year. Globally, the refining sector is the third largest producer of carbon dioxide after the electricity generation and cement industry. This greenhouse gases is a major cause of global warming and climate change and is a serious threat to human health and the environment. One way to reduce this greenhouse gas into the atmosphere is to reduce carbon dioxide by reversing this gas in the fuel cycle. The Fluid Catalytic Cracking unit (FCCU) is one of the emissions sources of this greenhouse gas in Abadan Refinery, which produces 230 tons per hour of combustion gases, it has 12. 7% mole of carbon dioxide. Identifying the sources of carbon dioxide emissions in Abadan Refinery and simulating the chemical absorption of this greenhouse gas and converting it into methanol fuel is one of the objectives of this study. Methods: In this research, the concentration of carbon dioxide emitted from the emission sources of Abadan Refinery has been measured by Testo 350-XL and GC. Due to the fact that the concentration of carbon dioxide in the combustion gases of the FCC unit was the highest amount, so the chemical absorption of carbon dioxide from the combustion gases of this unit by 30 wt% diethanolamine solvent and converted into methanol during a hydrogenation reaction has been simulated with Aspen Hysys software. Finally, the economic calculations of the project were performed. Results: The overall efficiency of chemical absorption of CO2 in the simulation with software is 92% and the purity of captured CO2 is 94. 6%. With this method, 1003 ton per day of carbon dioxide in FCC unit can be absorbed and recovered and also converted into methanol product. In the simulation of the conversion of recovered carbon dioxide into methanol, the amount of 686 ton per day of methanol with a purity of 99. 8% was obtained. The economic calculations of the project show that the cost of reducing emissions per ton of carbon dioxide is $ 19. The internal rate of return on the project is 22% and the net present value of the project is $ 92 million. The return time on investment of this project is 3 years. Conclusion: Diethanolamine has a high efficiency in absorbing carbon dioxide from combustion gases. By chemical absorption method with this amine, carbon dioxide pollutant can be recovered from combustion gases that produced in refineries and used as an inexpensive feed to produce methanol fuel. This method, in addition to creating added value, prevented the emission of this greenhouse gas into the environment.

هدف از این پژوهش بررسی اثر کیتوزان، تیمول و اتمسفر تغییر یافته بر ویژگی های فیزیکوشیمیایی، حسی و میکروبی خربزه تازه برش خورده بود. بدین منظور، برش های خربزه در محلول حاوی درصدهای مختلف کیتوزان (صفر، 1 و 2%) و تیمول (صفر، 25/0 و 5/0%) به مدت 2 دقیقه غوطه ور شدند. برش های تازه میوه پس از پوشش دهی و حذف محلول های اضافی و نمونه شاهد (پوشش داده نشده) در اتمسفر تغییریافته (10% دی اکسید کربن) و اتمسفر طبیعی بسته بندی و به مدت 8 روز در دمایC ͦͦ 4 نگهداری شدند. نتایج بیانگر افزایش میزان دی اکسید کربن و کاهش اکسیژن در بسته بندی تحت اتمسفر اصلاح شده و اتمسفر طبیعی همگام با افزایش دوره ماندگاری بود. اما در نمونه های پوشش دهی شده با کیتوزان و تیمول شدت کاهش اکسیژن و افزایش دی اکسیدکربن کمتر از نمونة شاهد بود. در پایان 8 روز نگهداری، افت وزنی در نمونه های پوشش دهی شده با کیتوزان و تیمول و نگهداری شده تحت اتمسفر تغییر یافته بسیار کمتراز نمونه شاهد بود (34/0% در مقایسه با 60/13%). افزایش غلظت کیتوزان و بسته بندی تحت اتمسفر تغییر یافته سبب افزایش حفظ میزان مواد جامد محلول، اسید قابل تیتراسیون، اسید اسکوربیک و سفتی بافت برش های خربزه شد، اما افزایش غلظت تیمول تاثیر معنی داری بر این ویژگی های کیفی نداشت. شاخص-های رنگی میزان سبزی- قرمزی (a*)، میزان آبی- زردی (b*)، میزان روشنایی (L*) و شاخص قهوه ای شدن (BI) نیز تحت تاثیر نوع بسته بندی و غلظت کیتوزان قرار گرفتند، اما، تیمار با تیمول بر شاخص های رنگی برش خربزه تاثیر معنی داری نداشت. اثر متقابل غلظت کیتوزان و غلظت اسانس نشان داد که برش های خربزه تیمار شده با غلظت 1% کیتوزان و غلظت های 25/0 و 5/0% تیمول دارای کمترین میزان بار میکروبی بودند. پوشش دهی با کیتوزان و تیمول و هم چنین نوع بسته بندی بر همه صفات حسی برش های خربزه (تاثیر معنی داری داشت (05/0 P<)؛ و ارزیابان در پذیرش کلی، غلظت 1%کیتوزان را بر غلظت 2% ترجیح دادند.

Background and aim: Due to significant role of air pollutants on lung diseases this study aimed to examine the effects of concentration of air pollutants (CO, SO2, NO2) on Spirometric lung function.Methods: The sample cities, Arak (as an industrial contaminated city) and Khomain, (as a non-contaminated non-industrial city), were divided into Ira 10 and 5 regions, respectively. A sample of air pollutants (CO, SO2, NO2) was measured randomly by PSI (Pollution Standard Index) machine throughout the year from spring to winter. Random samples consisted of 522 non-smokers from Khomain and 547 from Arak were selected. Pulmonary function tests were completed on all participants. The mean concentration of air pollutants and distribution index of lung capacity were subjected to regression analysis. Results: Analysis of the results showed that PSI in Arak was 101.83±4.54 and in Khomain was 89.17±18.58 (P<0.05). Measured values FVC and PEF in Arak were significant lower than Khomain (P<0.05). The mean values for the concentration of CO, SO2 and NO2 in Arak were higher than Khomain, although the differences were significant only for CO and SO2 (P<0.001). The three pollutants (NO2, SO2 and CO) showed a significant correlation between mean VC (P<0. 001) FVC, (P<0.05) with concentrations of SO2 and PEF with NO2 (P<0.001). In Arak, the correlation between the predicted FVC and concentration of CO was negative and significant.Conclusion: The mean value of concentration of SO2, CO and NO2 in Arak were higher than Khomain. In Arak, a significant negative correlation was also observed between FVC and the concentration of CO. These pollutants and their resources should be annually measured and monitored.

Reduction of fossil fuel reservoirs along with the environmental crisis associated with the fossil fuel combustion cause find the renewable and green resource of energies. Ethanol is an alternative fuel that is used as fuel in combination with other fuels and improves combustion efficiency and exhaust gasses properties. In this paper, combustion in automotive engines using different blends of gasoline-ethanol are studied to investigate the emissions of pollutants such as carbon monoxide, carbon dioxide, nitrogen oxides, and sulfur oxides. The simulation results showed that the blend of ethanol-gasoline significantly reduces exhaust emissions contain carbon dioxide, and sulfur oxides. The highest percentage of reduction in emission of greenhouse gasses is observed for 10% (V/V) of ethanol; however, by increasing engine speed, emission of carbon dioxide increases due to increased fuel consumption, while, unburned hydrocarbons and carbon monoxide emissions initially increases with increasing engine speed, and decreases by increasing the engine speed and temperature. Therefore, a mixture of gasoline-ethanol can be used as a substitute for fossil fuels.

Introduction: Diazinon is an organophosphate pesticides that widely used for agricultural pests and vectors. Diazinon resists to biodegradation so there is major concern about it. The aim of present work was to study the decompostionof diazinon by nano-photocatalytic ZnO-TiO2 in the presence of UVC radiation.Materials and Methods: This work is a laboratory-experimental study. Characterization of nanoparticles was determined through TEM pattern. The number of samples was determined by Taguchi statistical method. The samples with definite concentration of diazinon and nanopartical in different operational conditions were exposed to UVC radiation, individually .Diazinon concentration was measured using HPLC. Data analysis was performed using the software Minitab 16.Results: The results showed that with increasing reaction time, the removal of diazinon increases but by increasing the dose of nanoparticles and Diazinon concentration the removal rate decreases. The highest removal efficiency rate was 95%.Conclusion: The combination of catalysts is a new method for the removal of diazinon. The results showed that the photocatalytic nano-ZnO-TiO2 has a positive effect on diazinon degradation.