Reutilization of Agricultural Waste Lignin: Synergistic Modification of Dispersive Saline Soil in Western Jilin with Xanthan Gum

The collapse of dispersive saline soil slopes in western Jilin Province after exposure to water poses a serious threat to the construction of agricultural irrigation canals. This study discusses the use of lignin (8-10%) and xanthan gum (1.5-2.5%) to stabilise dispersive saline soils. The basic physical properties, dispersivity, mechanical properties, water stability, freeze-thaw cycle durability and curing mechanisms of the treated soils were mainly evaluated and summarised in the study. It was found that 10% lignin and 1.5% xanthan gum cemented soil particles to form a composite biopolymer, which improved the mechanical properties of the soil by 204.4% through increasing soil cohesion and changing the particle contact pattern. The two materials reduce the specific surface energy of particles by cementing fine particles, and the adsorption of exchangeable sodium ions by lignin and the water blocking effect of xanthan gum colloids well reduce the dispersion of the soil. Meanwhile, the solidified soil was tested to show a good durability against freeze-thaw cycles. The method provides an eco-friendly solution for the diversified exploitation of agricultural waste lignin and the stabilisation of agricultural dispersive saline soils.