Tóm tắt
Microbial biopolymers are introduced as a new soil binder which regarded to be environmentally-friendly materials in terms of low carbon emission and low impact on the soil ecosystem. In geotechnical engineering and agriculture, various gel-type materials have been used to improve the water absorbability of sandy soils, and control surface erosion. In this study, the soil-water characteristics of xanthan gum biopolymer-treated sand-clay mixtures are evaluated through a laboratory program using a soil-water characterization apparatus. Sand-clay mixtures are treated with different xanthan gum concentrations as 0% (untreated), 0.1%, 0.25%, 0.5%, 0.75% and 1.0%, to the mass of soil, respectively. Consequently, the xanthan gum-soil water characteristic curve results show the enhanced water holding capacity of soils with higher xanthan gum contents. The presence of xanthan gum hydrogels in the soil increases the initial and residual water contents. Biopolymers retain moisture loss from the soil, which makes the slope of the soil-water reduction curve to be more gradual.