Application of enzymatic calcification for dust control and rainfall erosion resistance improvement

Highlights: • EICP-PVAc treatment can control dust and improve rainfall erosion resistance. • PVAc addition is beneficial for the affixation of CaCO₃. • The higher surface strengths are attributed to the smaller particle size. Globally, most cities are facing severe challenges associated with dust pollution and it is of great significance to propose an effective and environmentally friendly dust control method. This study used enzymatically induced calcite precipitation (EICP) technology for dust control. Moreover, polyvinyl acetate (PVAc) was added to the cementation solution to improve its rainfall erosion resistance. The results showed that the optimum ratio of urease solution to cementation solution differed according to the concentrations of reactants in the cementation solution. Under combined EICP and PVAc (50 g/L) treatment, the stability of the dust-slope significantly improved. Moreover, little dust soil loss was washed out by simulated rainfall because of the more stable spatial structure of CaCO₃ precipitation. Furthermore, PVAc addition increased the surface strength of slopes, while the cemented layer became thinner. With this combined EICP and PVAc (50 g/L) treatment, in a field test, the treated area of the slope had higher surface strengths and stronger erosion resistance than untreated areas. These higher surface strengths were attributed to the smaller particle size, and the stronger cementing effect of grass seeds. These results demonstrated that EICP-PVAc treatment significantly controlled dust and mitigated surface erosion of dust-slopes. This represents promising potential for the prevention of dust pollution.