Enhanced rainfall erosion durability of enzymatically induced carbonate precipitation for dust control

摘要

Globally, most cities are facing severe challenges caused by dust pollution. Recently, the significant dust control application potential of the environmentally friendly enzymatically induced carbonate precipitation (EICP) has been demonstrated. However, repeated rainfall erosion negatively affects the long-term durability of several EICP treated areas. This study applied EICP and added either polyvinyl acetate (PVAc) or polyethylene glycol (PEG) to the cementation solution. The results showed that both PVAc and PEG could improve the shear resistance and rainfall-erosion resistance of treated dust soils. However, for repeated rainfall erosion, the surface strength and calcium carbonate (CaCO_3) contents of samples still decreased to less than 250 kPa and 1.1%, respectively. Therefore, combined EICP-PVAc-PEG treatment was proposed and the rainfall-erosion durability of treated dust soils was further studied. With the EICP-PVAc-PEG treatment, the dust samples achieved better shear resistance, higher surface strength, and better repeated rainfall-erosion resistance. Considering cost, cementation effects, and the effects of repeated rainfalls, EICP-PVAc-PEG treatment with 50 g/L PVAc and 30 g/L PEG was most suitable for dust control. The combined EICP-PVAc-PEG treatment significantly suppressed the generation of dust and improved the rainfall-erosion durability.