نشریه کاربرد شیمی در محیط زیست
پیاپی 26 (بهار 1395)

Desulfurization of fossil fuels such as gasoline is one of the important factors in pollution control of the environment because of sulfur dioxide emission due to combustion into the atmosphere. Conventional methods for desulfurization of gasoline for its aromatic contents have been considered. To this approach¡ biodesulfurization methods have been examined for desulfurization of sulfur containing aromatic compounds. Rhodococcus erythropolis supported on poly vinyl alcohol has been used for biodesulfurization of thiophene as gasoline model compound in n-hexane as the solvent. The obtaining results according to UV-Spectrophotometer analysis at 240 nm showed that upto 98 % of thiophene at the optimum condition of primary concentration about 80 ppm¡ pH= 7¡ adsorbent dose of 0.5 g¡ in 30°C and after 20 hrs of contact time has been removed. Equilibrium data and adsorption kinetics have been observed to obey the Freundlich isotherm and pseudo first-order kinetic models¡ respectively. Also the recovery of suppored biomass has been investigated. The alteration in surface morphology of biosorbent after supporting on polymer was investigated by FT-IR spectroscopy and SEM images.

Because construction of combined cycle power plant increasingly in our country as green power plants in one hand and their accidents on the other hand¡ In order to preservation and maintenance of the staff¡ the equipment¡ standards and Safety regulations for each section should be developed and implemented distinctly. Due to the possibility of identification of potential scenarios of hazard with FMEA method in combined cycle power plants and lack of a complete and Comprehensive classification of causes of accidents in related units to this workplace¡ purpose of this project is evaluation of risks of processing of combined cycle power plant FMEA method. In this research¡ by means of FMEA method¡ the potential risks of power plant were identified¡ analyzed and at last evaluated and necessary Interventions for emitting or reduction of detected intolerable risks is done. The research method is based on library research and being in the site continuously field visit forming FMEA team’s meetings and using the relevant resource. From 143 detected risks in this research¡ 52 of them were in intolerable range. Electric shock risk by having the most number of detected risks and intolerable and having higher RPN max and RPN averages¡ is considered as most dangerous power plant risk. Monitoring results after corrective actions show that the actions which have been done are desired so that the risks with high RPN has decreased significantly and that shows the suggested methods for evaluation of risks of the process combined cycle power plants with Heller Cooling Tower is appropriate.

During the refining processes without using a lot of gas and fuels released into the atmosphere directly through the produce. Flare gas is the country''s capital and if you are wasting prevent it¡ in addition to energy waste have to have fueled the country''s polluted air and hence the necessity of upgrading and optimization systems flaring considered important. So far¡ methods and ideas for slowing down and sent to flare gas recovery given that originally led to the reduction of gas emissions but it is possible to design targeted segments¡ gases sent to the flare important product made with high economic value. In this paper¡ using software HYSYS to simulate and evaluate economic GTL process for gas flow 8.176 million cubic feet is dedicated to the results equivalent to 116 barrels of GTL per day.

Due to environmental pollution as well as being non-renewable fossil fuels¡ the need to use modern methods to produce clean fuels and renewable energy such as solar¡ water¡ wind¡ nuclear energy and thermal energy even more sense. One of renewables is thermal energy. One of the most important methods of storage¡ thermal energy or the phase-change material that during the phase change¡ thermal energy storage and release when necessary. Phase-change material with all the benefits that they have a series of problems such as leakage and low thermal conductivity. This can be improved by using nano composite materials. In this study¡ paraffin as phase-change material and nano-particle TiO2 as to improve the thermal properties during freezing process is used. To study the properties of nano composite thermal behavior such as phase change temperatures¡ freezing latent heat as well as morphology¡ respectively tests¡ DSC¡ SEM¡ FT-IR was performed on samples. The results showed that by taking all circumstances¡ TiO2 nano composites in three wt% are suitable samples. These results can be used in thermal management systems designed to be large.

Although antibiotics are used in the treatment of infectious diseases¡ there are many problems such as adverse drug reactions and resistance to antibiotics. Plants can be considered as a substitute for synthetic drugs.Rossadamascena is one of medicinal plants which has a long history in traditional medicine And is used in the treatment of many diseases. In this comparative studies Antibacterial effect of Rossadamascena extract polar¡ semi-polar and non-polar fractions on Staphylococcus aurous¡ E.coli and Pseudomonas aeruginosa bacteria. Rossadamascena plant was used in this study.Initially extracts of methanol¡ chloroform and ether of Rossadamascena was prepared and the effect of different concentrations of the extracts were evaluated.All experiments were performed with the release of the wells and determine the MIC and MBC on standard strains of Staphylococcus aureus¡Escherichiacoli¡ and Pseudomonas aeruginosa. Chloroform extract of Rossadamascena plant at a concentration of 12.5 micrograms per milliliterinhibits the growth of the Gram-positive bacteria Staphylococcus aureus by microplate.Whereas¡ higher concentrations are needed to effecting on gram-negative bacteria Escherichiacoli and Pseudomonas aeruginosa. Chloroform extract of Rossadamascena plant have most inhibitory and killing effects on Gram-positive Staphylococcus aureus; and the methanol extract of this plant in concentration of 25 micrograms per milliliter and have more killing and inhibitory effects on Gram-positive bacteria Staphylococcus aureus.

There are chemical compounds¡ even in small amounts if it is more than the amount prescribed in international standards¡ it will be poisoning people and all creatures. Nitrate compounds are pollutant of groundwater resources in recent years due to agricultural expansion and human activities are increasing their average. This cross-sectional study is to evaluate and compare with the standard¡ the concentration of some chemical parameters of water resources in a number of villages Nazloo Urmia city. Concentration of ions of nitrite and nitrate in any of the samples higher than standard values but also the concentration of ammonium nitrate in summer¡ the intensity of agricultural operations is increasing and is likely to be due to excessive use of chemical fertilizers and nitrate leaching of soil caused by irrigation is repeated.

In this article¡ the frequency of products bubble boiling lacustrine saturated in pure acetone and water in term of heat flux in range of 1000 to 75000 assigned watt per square meter on horizontal cylindrical Brass were studied and it was found the solution that was better at frequencies produce bubbles. Experimental data were compared with existing models¡ Fault models were calculated and shown that Hatton and Hall Models for pure acetone and Ivey model in pure water had been lowest fault and Macfadden model had the most fault estimated for both solutions in comparison with experimental data.

In this paper¡ by using induced crystallization¡ induction time for neomycin sulfate nanoparticles nucleation is measured at 25˚C and different super saturations by using anti-solvent acetone in the presence of consumption solution containing surfactant poly vinyl pyrrolidone (PVP). Also primary nucleation compared with the secondary nucleation¡ which secondary nucleation was predominant over primary. By using TEM device photos were taken from nanoparticle that the range of nanoparticle size was between 20 nm to 40 nm. Since measured induction time data are as predicted by the classical theory of nucleation¡ nucleation variation range from 0.276 (#/s.m3) to 0.2841 (#/s.m3) were calculated. In addition the results showed¡ in presence of consumption solutions containing surfactant PVP¡ by increasing the super saturation¡ induction time reduced.