Study on characteristics and microscopic mechanism of composite environment-friendly dust suppressant for urban construction site soil fugitive dust based on response surface methodology optimization.

Soil fugitive dust pollution caused by urban construction sites is a significant problem. To improve the dust suppression efficiency on the urban construction sites, hydroxypropyl guar (HPG), dodecyl dimethyl amine oxide (OB-2), and hydroxypropyl methylcellulose (HPMC) were selected as individual components of the composite dust suppressant using a single-factor test. The response surface methodology (RSM) was used to determine the optimal mixing proportions. After preparation, the characteristics of the composite dust suppressant were tested. Fourier-transform infrared spectroscopy and scanning electron microscopy (SEM) were used to characterize the composite dust suppressant and explore its mechanism. The results showed that 0.327% HPG, 0.6% OB-2, and 0.5% HPMC were the best compound concentrations. Under optimum conditions, the viscosity of the composite dust suppressant was 151.1 [Formula: see text], penetration time was 61.4 s, and water retention rate was 30.67%. Compared with traditional dust control by spraying water, it showed better resistance to evaporation at high temperatures and better wind erosion resistance. The antievaporation rate was 39.42% at 60 °C. After 11 d of continuous wind erosion at level 7, the wind erosion resistance rate was as high as 98.24%. The reason for the excellent dust suppression effect of the composite dust suppressant is that the methyl and hydroxyl groups in the solution diffuse to the surface of the soil fugitive dust particles using Brownian motion and gradually approach the corresponding groups in the soil fugitive dust particles. When the distance between the two reaches 10 [Formula: see text], adsorption occurs, causing small dust particles to stick together. Because of the stability of the covalent bonds in the methyl and hydroxyl groups, a stable solidified layer is formed on the soil fugitive dust surface after the evaporation of the composite dust inhibitor solution, thereby avoiding secondary dust. In addition, the composite dust suppressant is noncorrosive and friendly to the construction site environment. Therefore, the composite dust suppressant can effectively reduce soil fugitive dust, alleviate environmental pollution, and provide a reference for preventing and controlling soil fugitive dust on urban construction sites and preparing composite environment-friendly dust suppressants.