پديد آورنده :
شيرواني، مهران
عنوان :
برهم كنش كادميوم با كانيهاي پاليگورسكيت، سپيوليت، كلسيت
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي
صفحه شمار :
چهارده، 154، [II] ص.: جدول، نمودار
يادداشت :
ص. ع. به فارسي و انگليسي
استاد راهنما :
حسين شريعتمداري، محمود كلباسي
استاد مشاور :
فرشيد نوربخش، بيژن نجفي
توصيفگر ها :
منشا كادميم , گونه هاي كادميم , رس هاي سيليكاتي , ليگاندهاي آلي , آلكادين فسفاتاز
استاد داور :
نجفعلي كريميان، عليرضا حسين پور، مجيد افيوني، جهانگير عابدي
تاريخ ورود اطلاعات :
1396/02/30
كد ايرانداك :
ID165 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتال
چكيده انگليسي :
156Abstract Interaction of cadmium Cd with soil constituents greatly influences the mobility andbioavailability of this metal in soil environment In this research the equilibria and kinetics ofCd sorption and desorption reactions of palygorskite PAL sepiolite SEP and calcite CAL as minerals typically found in arid and semi arid region soils were investigated Interaction ofCd with alkaline phosphatase AP enzyme immobilized on PAL and SEP were also studied This research consisted of four studies In the first study kinetics of Cd sorption on PAL SEP and CAL were investigated andthe influences of acetate ACT and citrate CIT as organic acid anions and desferrioxamine B DFOB as a hydroxamate siderophore on Cd sorption were studied The time dependent Cdsorption data was well described by pseudo second order Elovich and power function kineticmodels ACT and CIT ligands generally decreased Cd retention rates with inhibitory effect ofCIT being more pronounced The DFOB on the other hand enhanced the rate of Cd uptake bythe sorbents In the second study Cd sorption and desorption isotherms on PAL SEP and CALand the possible irreversibility and hysteresis of Cd sorption desorption were investigated Theresults showed that Langmuir and Freundlich isotherms adequately fitted the equilibriumsorption data The sorption and desorption reactions however did not provide the sameisotherms indicating that hysteresis occurred in Cd sorption desorption processes The affinityof Cd for solid phase increased from forward sorption to reverse desorption directionbecause the Cd partitioning coefficients calculated from desorption isotherms were higher thanthose obtained from corresponding sorption isotherms In the third study the influences ofACT CIT and DFOB ligands and aging on the quantity and the rate of Cd desorption from PALand SEP was examined Among the kinetic equations tested the pseudo second order modelgenerally showed the best fits to experimental kinetic data Addition of the organic ligandsgenerally increased the extent and the rate of Cd desorption from the minerals however theenhancement effect of DFOB was more pronounced Increasing the initial contact time betweenCd and the minerals from 24 hours to 31 days decreased the rates and proportions of Cddesorped In the fourth study kinetic parameters i e Michaelis constant km and maximumreaction velocity Vmax of alkaline phosphatase AP enzyme immobilized on PAL and SEPminerals were compared to those of the free AP The inhibitory effects of Cd on the kinetics ofthe free and immobilized AP also were investigated The immobilized AP showed considerablyhigher km and slightly lower Vmax values compared to those of the free enzyme indicating thatclay minerals possibly showed competitive inhibitory effect on the AP activity Substantialincreases were observed in the km constants of the free and immobilized enzymes upon Cdaddition to the systems showing a significant decrease in the affinity of AP to the substrate inthe presence of Cd ions The increases in km with no significant change in Vmax values mayindicate that the inhibitory effect of Cd on AP activities were competitive
استاد راهنما :
حسين شريعتمداري، محمود كلباسي
استاد مشاور :
فرشيد نوربخش، بيژن نجفي
استاد داور :
نجفعلي كريميان، عليرضا حسين پور، مجيد افيوني، جهانگير عابدي
