j Behin - Chemical Engineering Department, Faculty of Engineering, Razi University, Kermanshah, Iran
m Hosseini - Chemical Engineering Department, Faculty of Engineering, Razi University, Kermanshah, Iran

Kinetics of nitrogen (urea) release in low-density polyethylene-coated urea was examined for different coating percentages of 2.9%, 4.8%, and 5.7%. Three different mathematical models named as power law expression, first-order kinetics, and modified Schwartz model were used.Kinetics constants were also calculated by fitting the models to experimental data. The modified Schwartz model gives the best results compared to the others. This modified model, which is used in pharmaceutics industries, can be used to predict the nutrients release from polyethylene-coated urea in the chemical fertilizer industries

Controlled release, Fertilizer, Kinetics of release, Polyethylene, Urea