Kinetics of Potassium Desorption from the Loess Soil, Soil Mixed with Zeolite and the Clinoptilolite Zeolite as Influenced by Calcium and Ammonium
Title:
Kinetics of Potassium Desorption from the Loess Soil, Soil Mixed with Zeolite and the Clinoptilolite Zeolite as Influenced by Calcium and Ammonium
Author:
M. Rezaei S.A.R. Movahedi Naeini
Appeared in:
Journal of applied sciences
Paging:
Volume 9 (2009) nr. 18 pages 3335-3342
Year:
2009
Contents:
The rate of K+ release from soils can significantly influence K+ fertility of soils. The objectives of this study were investigated the effect of different calcium concentrations (0, 0.028, 0.057, 0.085, 0.128 and 0.171 mg L-1) and different ammonium concentrations (0, 40, 60, 90, 120 and 140 mg L-1) on potassium isothermal desorption kinetics of diluted suspensions of a soil, the Iranian natural clinoptilolite zeolite and their incorporation (within 2 and 1800 h), application of some kinetic models and correlation between potassium desorption kinetic coefficients of the best models with the calcium concentration. Potassium desorption was initially fast (first 192 h) with Ca2+ and NH4+ addition and continued during next stage (192-1800 h) with low speed until the end of the experiment. Also, increasing the Ca2+ and NH4+ solution concentration increased the potassium desorption in all of treatments. The potassium released from NH4+ treatments was more than Ca2+ treatment in equal equivalent of Ca2+ and NH4+. Zeolite decreased K+ desorption rate by incorption with soil. The kinetic equations used to estimate data were zero order, first order, simple Elovich, parabolic diffusion and power function. The Elovich model described the desorption processes on soil and soil+zeolit and zeolite in NH4+ treatment (0.628<r2<0.990). Elovich, first order, zero order and power function models described desorption processes, respectively for zeolite well (0.87<r2<0.97). The models indicated that K+ desorption was diffusion controlled. Result shows that zeolite release K+ slowly.
Publisher:
Asian Network for Scientific Information (provided by DOAJ)
Journal description