Assessment of bentonite, zeolite, and sodium alginate for soil stabilization in dust hotspots

Dust emissions from degraded soils in arid and semi-arid regions pose significant environmental and health risks, requiring sustainable mitigation strategies. This study evaluates bentonite, zeolite, and sodium alginate as soil stabilizers to reduce dust emissions and enhance crust formation in three major dust hotspots (DS1, DS2, and DS3) around Lake Urmia, Iran. Soil samples were treated with bentonite and zeolite at 2%, 4%, and 6% w/w, with and without 0.5% w/w sodium alginate. Crust thickness, mean compressive strength, and maximum compressive strength were measured, followed by FTIR and FESEM analyses to assess structural changes. Results showed that 6% bentonite substantially improved soil stability, increasing crust thickness and compressive strength to 15.22 mm and 5260.42 kPa in DS2, respectively. Zeolite at the same concentration provided moderate improvements, producing a crust thickness of 10.11 mm and compressive strength of 3333.94 kPa, particularly in finer-textured soils. Adding sodium alginate enhanced crust formation at lower bentonite levels but exhibited inconsistent effects on compressive strength. FTIR analysis confirmed strengthened Si-(Al)-O and Si–O-Al stretching bands, and FESEM imaging revealed denser, more cohesive crust structures following treatment. This study provides a novel, comparative assessment of mineral and biopolymer stabilizers across multiple dust hotspots with contrasting soil textures. The findings offer practical guidance for selecting cost-effective and environmentally sustainable soil stabilization strategies tailored to site-specific conditions. Overall, the results highlight bentonite as the most effective stabilizer, with zeolite and sodium alginate offering complementary, site-specific benefits for sustainable dust-mitigation approaches.