Phosphate desorption from soil in anion-exchange resin extraction

• Main Author: Erkki Aura
• Format: Article
• Language: English
• Published: Scientific Agricultural Society of Finland 1978-07-01
• Series: Agricultural and Food Science
• Online Access: https://journal.fi/afs/article/view/71984

An attempt was made to clarify the mechanisms of phosphate desorption using the anion exchange resin method for extraction of phosphorus from soil. It was shown that there is a linear dependence between the amount of phosphorus desorbed and the square root of the desorption time. Through theoretical examination it was concluded that the above-mentioned relation between the desorption and time is a result of the diffusion of phosphate from porous soil medium. Using this interpretation of the desorption curve as a basis, the activation energy of the phosphate desorption was calculated from the experimental results obtained with resin extraction at different temperatures. The activation energy values were 32—64 kJ/mol depending on soils involved. In application of the results, the mechanisms and rate at different steps of the desorption were examined.