Soil Desalination via Poly(vinyl alcohol) Borate Hydrogel

Abstract

Saline and sodic soil sample was collected from salty beach. Polyvinyl alcohol borate hydrogel due to its cation attracting ability was utilized as an adsorbent for the removal of excess cations responsible for the salinity and sodicity of soil. Experimental data were collected before treatment and after each treatment using 1 : 2 by weight soil to water extract method. Electrical conductivity and pH were observed. The amounts of sodium, potassium, magnesium, and calcium ions were determined by flame photometry and atomic absorption spectrometry. From data it was evaluated that there is the decrease in electrical conductivity and amounts of cations after desalinating soil that was previously categorized as saline. Sodium adsorption ratio and exchangeable sodium percentage were also determined and found to decrease after treatment of soil sample with polyvinyl alcohol borate hydrogel. After treatment, soil becomes nonsaline but remains sodic. This was due to the fact that it has the higher sodium ion content in comparison with other cations. Thus, further remediation to decrease the sodicity of soil was suggested before its application for agricultural purposes.