Water retention properties of xanthan gum biopolymer-treated soils

This study aims to estimate the effects of xanthan gum biopolymer on the wetting and drying processes of soils. Xanthan gum was used to treat jumunjin sand and sand/clay mixture with different content to the mass of dried soil. The wetting and drying soilwater characteristics of xanthan gum biopolymer-treated sand were investigated using capillary rise open tubes and Fredlund-type SWCC device, respectively. The results show that xanthan gum has a significant effect on controlling the movement of water in the soil. Xanthan gum biopolymer shapes the drying soil-water characteristic of the soils and forms the nonlinear relationship between xanthan gum content and soil-water characteristic parameters of the treated soils. Xanthan gum significantly reduces the capillary conductivity of soil down to 10−7 ∼ 10−8 m/s as the soil treated with 1.0% xanthan gum. Xanthan gum affects the capillary equilibrium process of water differently in wetting tests as well. Furthermore, the wetting results show the role of clay particles in the flow controlling performance of xanthan gum.