استخراج و غني سازي اسميوم از پساب اسميوم مصنوعي با استفاده از روش غشاء مايع نانو امولسيوني

چكيده انگليسي :

126 Degree M Sc Extraction and Enrichment of Osmium from Synthesized Wastewater by Nano emulsion Liquid Membrane TechniqueAuthor Hadi Davan Yamchi H davan@ce iut ac irSupervisor Kayghobad Shams K shams@cc iut ac irDepartment of Chemical EngineeringDate of Submission 2014 09 21Language FarsiAbstractOsmium is one of the chemical elements that in periodic table of elements is in the platinum group metals This metal is one ofthe rarest elemnents in the earth crust and is found as a trace element in alloys mostly in platinum ores Osmium oxide in formof osmium tetroxide is a powerful oxidizer which boils at 130 C Osmium because of its high density is commonly known asthe hardest metal This metal within the platinum group metals has the highest melting point and lowest vapor pressure Thecommon oxidation states of osmium are 2 3 4 and 8 but it can form compounds with oxidation states ranging fromand 2 to 8 In this research extraction and enrichment of osmium IV from dilute synthesized wastewater prepared by disolution ofosmium tetroxide in hydrochloric acid using nano emulsion liquid membrane NELM technique is investigated In emulsionliquid membrane ELM process because of many advantages such as high mass transfer flux induced by high mass transferarea presence of chemical reaction and lack of equilibrium limitations has attracted much attention in recent deacades Extraction of heavy metals from dilute solutions is one of the most important applications of this method The surface actaiveagent carrier membrane phase and internal phase used in this study are Span 80 ethyhexyl phosphoric acid liquid paraffin and hydrochloric aacid Considering the large number of effective parameters and their interactions in this process foroptimization of the number of experiments Taguchi method of design of experiments and Minitab 16 software package wasused and 25 experiments was performed to study extraction and enrichment of Os IV via NELM The average size distribution of the nano emulsion using dynamic light scattering DLS was determined to be 64 3 nm Effectsof concentration of surface active agent concentration of carrier contact time agitation speed and volume ratio of membranephase to feed on extraction and enrichment of Os IV were studied and optimum values for maximization of extraction andenrichment and minimization of emulsion swelling which are the responses of this system were determined The optimumvalues for reaching the maximum extraction 98 2 based on design of experiments by Taguchi method are as follow Concentration of surface active agent 2 V V concentration of the carrier 3 V V contact time 20 min mixer speed 750RPM and volumetric ratio of membrane to feed 60 to 100 Effects of various parameters including concentration of surfaceactive agent emulsification time concentration of the internal phase stripping phase and volumetric ratio of the internalphase to the oil phase on emulsion stability were studied and the following optimum values were determined Concentration ofsurface active agent 1 5 V V time of emulsification 6 min concentration of the internal phase 0 8 M and volumetric ratio ofthe internal phase to the oil phase 1 to 1 Then by performing real experiments effects of concentration of surface active agent concentration of the carrier speed ofagitator contact time volumetric ratio of membrane phase to feed and concentration of the internal phase stripping phase onextraction and enrichment were studied The optimal conditions for maximum extraction 99 were as follows concentrationof surface active agent 1 5 V V concentration of V V contact time 20 min speed of the agitator 750 RPM concentrationof the internal phase 0 8 M and volumetric ratio of membrane to feed 30 to 100 Finally extraction of Os IV fromsynthesized wastewater using a laboratory continuous emulsion liquid membrane column at mixing speeds of 200 300 and400 RPM under similar conditions with those of batch emulsion membrane was studied and compared Results showed

دوان يامچي، هادي

استخراج و غني سازي اسميوم از پساب اسميوم مصنوعي با استفاده از روش غشاء مايع نانو امولسيوني

تورم امولسيون , غشا مايع نانو امولسيوني , فرآيندپيوسته