Bio-inspired Bacterial/Sodium Alginate Hydrogel Dust Suppressant with Strong Consolidation and High Water Retention

Dust pollution threatens ecological stability and human health, but conventional suppressants suffer from short durability, high water demand, and toxicity. This study developed a bio-inspired bacterial/sodium alginate (SA) hydrogel (BSH) dust suppressant composed of Bacillus mucilaginosus (B.m), SA, and NaHCO3. Its application uses a two-step process: first spraying BSH for physical dust adhesion and then CaCl2 to supply Ca2+ ions. Carbonic anhydrase secreted by B.m catalyzes the hydration of ambient CO2 into CO32–, which reacts with Ca2+ to form CaCO3; NaHCO3 further enhances CO32– availability, promoting stable calcite and dust matrix consolidation. The BSH exhibits favorable interfacial properties: a low surface tension of 31 mN/m and strong wettability, with a contact angle of 60°. The hydrogel suppressant achieves a dust suppression efficiency of up to 99.76%, outperforming conventional formulations, and maintains >95% efficiency over a 7 day wind erosion trial, alongside superior water retention. This scalable, biodegradable hydrogel enables long-term dust mitigation and synergizes with greenhouse gas sequestration, shifting the paradigm from passive dust control to climate-friendly environmental management.