EFFECT OF WATER IONIC STRENGTH ON SODIUM DESORPTION FOR SOME CALCAREOUS SOILS IN NINEVEH PROVINCE

Abstract

A laboratory study was conducted to determine sodium desorption behavior from exchange positions of soil solid phase because of a quiet water flow. Using sulfuric water collected from a sulfuric spring and a chlorine water from Tigris river. The flow was through two disturbed soil columns. Soils were sampled from Fadhlia and Hamdania locations in Nineveh province/ northern Iraq. Waters flow were persisted for 240 minutes with 4 cm highness over soils surface was maintained. Leachates were collected every 10 minutes for a total ten extracts which analyzed for Na+. Three mathematical kinetic description were considered as an accumulative soluble Na+, Na+ expressed by SAR and ESP concepts , sequences as parabolic diffusion, zero order, 1st order, Elovitch and power function (poly ordered) models were applied. Mathematical descriptions revealed succession of 1st order and power function models. Na+ desorption coefficient rate values by 1st order model were ranged from 96 ×10-3 - 185 × 10-3 minute for chlorine water, for sulfuric water were from 10 ×10-3 - 34×10-3 minute for both locations respectively, while desorption coefficient rate values according to power function model were 686 ×10-3 , 683×10-3 , 634×10-3 mg.kg-1.min..-1 respectively. Results referred also that Na+ desorption coefficient rate values was proportionally increased with waters ionic strength.