Development and performance characterization of a composite dust suppressant for Yellow River alluvial silt using response surface methodology

The construction site covered with Yellow River alluvial silt (YRAS) is prone to generate dust, which has always been troubling to the builders. The purpose of this study was to develop a composite dust suppressant aimed at YRAS dust for the first time. First, the formulation of composite dust suppressant was determined using the response surface methodology. Then, the mechanical properties and weather resistance of YRAS solidified layer, and the dust suppression efficiency and environmental performance of the composite dust suppressant were evaluated. The test results showed that the optimum mixing concentration of composite dust suppressant was 2.62% sodium alginate (SA), 2.37% carboxymethyl chitosan (CMCS), 0.21% polyacrylic acid sodium, and 0.85% sodium dodecyl sulfate. The YRAS sprayed with composite dust suppressant formed a solidified layer with sufficient hardness and compressive strength. The YRAS solidified layer had good freeze-thaw resistance, rain erosion resistance, and wind erosion resistance. The composite dust suppressant effectively reduced the con-centration of total suspended particulate, PM10 and PM2.5 produced by YRAS, and the effect could last for one month. The composite dust suppressant was non-toxic, low metal corrosive and degradable, and its main raw materials (SA and CMCS) were obtained from nature. The above results show that the composite dust suppressant can effectively and long-term suppress the dust of YRAS, and is environmentally friendly and appropriate for clean production.