Evaluation of Langmuir and Frendlich isotherm equation for Zinc Adsorption in some calcareous soil of Erbil province north of Iraq.
H. S. Y. Akrawi, M.A. Al-Obaidi, Ch. H. Abdulrahman
Abstract
Abstract The purpose of this study soil samples were to investigate of Zinc concentrations on the mechanism of adsorption phenomena in four calcareous soils (Choman, Qoshtepe, Herir, and Soran) from Erbil North Iraq classified (calciorthids). Isotherm adsorption was studied by using the Batch technique, 2 g soil was shaken with 40 ml 0.01M CaCl 2 containing Zn concentrations of 0, 1, 2, 4, 8, 16, 32, 64, 128, and 256 mg Zn l-1 for 24 hours at 298K. Zn adsorption under isotherm reaction 298K. The adsorption data were described by using Langmuir and Freundlich equations. The results showed that the concentration of adsorption was increased by an increase of Zn level added to Soils. According to the Langmuir equation, the maximum adsorption capacity of Zn was higher in Qoshtepe, Herir Soils. 666 mg kg −1 while the lower value was recorded in Soran soil. Bonding energy was higher in Soran 0.4050 mg L −1 , while the lower value was recorded in Choman Soils. 0.0184 mg L-1 soil MBC was higher in Soran Soil. 134.87 mg kg −1 while the lower value was recorded in Choman 7.65 soil, also the results showed that reaction was spontaneous with Negative free energy, were higher in Soil. -2.16 while the lower value was recorded in Herir soil -1.94 joule.mole −1 .degree-1 for Soil. And RL value was higher in Choman Soil 0.71, while the lower value was recorded in Soran soil 0.32. The values of qm constant Dubinin-Radushkevich (D-R isotherm) which is the adsorption capacity mol g −1 ranged from -2.3007 to -3.6758