Study on the performance and mechanism of extracellular polymer substances (EPS) in dust suppression

Microbial dust suppressants are a green method to prevent and control coal dust, but the role of extracellular polymer substances (EPS) has rarely been studied. Therefore, this paper studied the effect of different EPS concentrations (0, 0.05%, 0.10%, and 0.15% w/v) on dust suppression. The results showed that the dust suppression efficiency increased with the EPS concentration. When the EPS concentration reached 0.15%, the evaporation resistance and wind erosion resistance of coal dust were improved by 37.5% and 89.0%, respectively, compared with water-treated samples (p < 0.05). The contact angle of EPS-added samples was lower than that of water-treated samples and decreased to 57.35° at the highest concentration (0.15%), indicating that EPS enhanced the wettability and reduced the surface tension. Furthermore, changes in the protein and polysaccharide contents in EPS before and after dust suppression showed that the adhesion effect of polysaccharides was greater during dust suppression.