Preparation of eco-friendly dust suppressant by extracting biological enzyme from jack bean: Performance evaluation...

Soil dust in infrastructure construction sites seriously affects the working environment. In the study, urease is a biological enzyme extracted from jack bean, which is used as the core material to prepare dust suppressant. The best urease activity was observed at bean flour mass to Citric Acid-Sodium Citrate (CASC) volume ratio of 5:14. Urease activity increased with temperature rise and showed a trend of first increasing then decreasing with pH increase, with highest activity at pH 8. The precipitation rate of CaCO₃ reached the highest when CaCl₂-urea solution was 0.6 mol/L. The wind erosion resistance rate of soil dust samples treated with dust suppressant was 98.58 % under 120 min wind erosion. Under 6 h drying, the water retention rate was 32.67 %. The average hardness of the solidified layer is 62 HA. Under one week of natural degradation, the degradation rate was 4.65 %. In a one-month field experiment, the average total suspended particles (TSP) concentration in the experimental area of dust suppressant was 60.8 μg/m³. By analyzing the microstructure of dust samples, the reason for its excellent dust suppression performance is that there are many calcite type CaCO₃. The study has important engineering application value for controlling soil dust.