كاربرد پوسته برنج در حذف هيدروكربن هاي نفتي از محيط آبي

چكيده انگليسي :

92 Use of Rice Husk For Removal of Oil Hydrocarbons From Aqueous Environment Zahra Razavi Dinani z razavidinani@gmail com February 29 2012 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiDr Nourollah Mirghaffari mnorolah@cc iut ac irDr Behzad Rezaei rezaei@cc iut ac irAbstractOne of the most serious environmental problems that can pose irreversible economical and ecologicalimpacts is oil pollution Different methods are used for remediation of aqueous environment contaminated byoil compounds which classified into three main groups namely physical chemical and biological methods Each of these methods have some advantages and disadvantages Recently use of sorbents for removal ofpollutants particularly oil compounds and its derivatives from polluted water has drawn great attention Inmany countries such as Iran rice hull rice husk is an agriculture waste that burnt in some cases and causesthe air pollution In the present study the raw and thermal treated rice hull were used as adsorbents forremoval of three oil compounds with different viscosities in aqueous environment including crude oil engine oil and used spent oil Rice husk samples modified by thermal treatment in nitrogen and airatmospheres at 600 for 1 h The oil adsorption capacity was determined by weighting method The sorbentswere characterized using composition analysis CHNSO thermal analysis TGA FT IR spectroscopy and scanningelectron microscopy SEM The effect of various parameters including pH contact time particle size initial oilconcentration adsorbent dose on adsorption were investigated The results showed that adsorption kinetic wasrapid and the kinetic data for oil sorption by three adsorbents were precisely described by pseudo secondorder models The change in the pH of oil solution from 1 10 had no effect in the adsorption of oilcompounds The decrease of particle size of the raw rice hulls reduced oil sorption percent However particle size of treated adsorbents except for adsorption of used oil had no effect on the adsorption percent ofother oil compounds Raw rice hull and rice hull ash have specific adsorption capacity for oil compounds and after adsorption of certain oil concentration adsorption remains constant and was not increased byaddition of adsorbent amount Pyrolyzed adsorbent had the high oil capacity The removal of total engine oil used oil and crude oil in water medium need 2 3 and 5 6 times of pyrolyzed adsorbent respectively Theadsorption of crude oil and used oil samples on rice hull and rice hull ash obeyed the Freundlich isothermmodels and on pyrolyzed adsorbent was fitted well by Langmuir isotherm model But engine oil adsorptionon rice hull and pyrolyzed adsorbent was described well by the Langmuir and its adsorption on rice hull ashfitted by Freundlich model Maximum capacity of adsorption for engine oil used oil and crude oil bypyrolyzed adsorbent was 2000 1250 and 1000 mg g respectively Pyrolyzed adsorbent indicated the higherperformance in comparison with rice hull ash for adsorption of three oil compounds In general use of ricehull as adsorbent remove the environmental pollutants as well as reduce the problems of burning and disposalof agricultural by products Key words rice husk rice hull oil pollution adsorption thermal treatment Adsorption kinetic andisotherms

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كاربرد پوسته برنج در حذف هيدروكربن هاي نفتي از محيط آبي

آلودگي نفتي , جذب , تيمار حرارتي , سينتيك جذب , هم دماي جذب