6836

6378

كارشناسي ارشد

علوم خاك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1390

پانزده، 156ص.: مصور، جدول، نمودار

ص.ع.به فارسي و انگليسي

حسين شريعتمداري، حسين خادمي

مهران شيرواني

19/4/91

محمدعلي حاج عباسي، جهانگير عابدي

1396/09/14

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6378

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Sorption and Desorption of Cd and Ni by Iranian Bentonite Zeolite and Sepiolite in the Presence of Calcite Atefe Feizbakhshian a feizbakhshian@ag iut ac ir Feb 18 2012 Department of Soil Science Isfahan University of Technonlgy Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Hossein Shariatmadari E mail address shariat@cc iut ac irSupervisor Hossein khademi E mail address hkhademi@cc iut ac ir AbstractThe high pollution of environment with heavy metals due to the application of various industrial wastesand sluges has forced researchers to develop several ways to remove and or decrease the harmful impactof these metals Absorption of these elements by natural materials is one of the best controlling methods In this research Iranian natural bentonite zeolite and sepiolite minerals in the presence of calcite havebeen used as absorbent of nickel and cadmium Sepiolite and bentonite samples were obtained from Yazdmines while the zeolite sample was taken from Siahzagh mine in Semnan X ray diffraction and elemental analyses and cation exchangable capacity measurment of the minerals were carried out Afterthe removal of carbonate from samples they were mixed with 0 5 10 and 20 by weight of analyticalgrade calcite All the sorption experiments were conducted with batch methods in 0 01 M Ca NO3 2solution with 3 replications at labratory tempreture 23 2 C and with sorbent concentrations of 1 Avolume of 30 ml of Ni II and Cd II solutions with 0 3g of sorbents was placed in polyethylen tubes Theinitial concentrstion of Ni II and Cd II for all the sorbents ranged from 5 to 250 mg L 1 and 5 to 180 mgL 1 respectively The suspensions were shaken for 24 h by a rotary shaker and then centrifiuged at 2000gfor 10 minutes The Ni II and Cd II concentrstions of the supernatant were determined by an atomicabsorption spectrophotometer The pH of the equilibrium solution was also randomly measured TheFreundlich Langmuir and Koble Corrigan adsorption models were well fitted the sorption data Bentoniteand sepiolite had maximum sorption of Ni II and Cd II respectively Adsorption of both elementsincreased with an increase in calcite content of the sorbent system This could be attributed to the increasein pH and also the produation of new species of metals and the precipitation of metals Bentoniteadsorbed the highest amount of Ni whereas sepiolite could adsorb the highest amount of Cd Kineticsorption experiments of Ni II and Cd II were carried out under the same conditions as the sorptionisotherms but with the initial concentration of 250 and 180 mg L 1 respectively for a period of 15minutes to 24 h The results indicated the kinetic sorption of both elements were well fitted with eluvich power function and parabolic diffiusion kinetic models The time needed to reach equilibrium depends onthe type of sorbent mineral and the amount of calcite added The higher the amount of calcite the higherthe rate of sortion For a given time period the amount of Ni II sorbed by bentonite and that of Cd II sorbed on sepiolite were higher than the other systems Desorption experiments were carried out onenriched sorbent samples using Ni II and Cd II solutions with the concentrations of 250 and 180 mg L 1 respectively in the background electerolyte solution of 0 01 M Ca NO3 2 Desorption Experimentcontinued until the concentration of Ni II or Cd II reached below the detection level of the atomic

حسين شريعتمداري، حسين خادمي

مهران شيرواني

محمدعلي حاج عباسي، جهانگير عابدي