Synergistic effect of modified konjac glucomannan and biological enzyme induced carbonate precipitation on the biocementation of soil fugitive dust.

Abstract

Soil fugitive dust poses a serious threat to human health, the plant-derived polysaccharide konjac glucomannan was modified to obtain konjac glucomannan-acrylic acid graft copolymer (KGMP), which was combined with enzyme induced carbonate precipitation (EICP) to control it. The performance of KGMP-EICP was evaluated. Microstructure characterization was performed on the treated soil fugitive dust samples, and molecular dynamics simulations were employed to investigate how KGMP regulates the nucleation of calcium carbonate, thereby elucidating the fugitive dust control principle of KGMP-EICP. Results indicate that the concentration of KGMP at 3 mg/mL maximizes the yield of calcium carbonate in EICP. KGMP improves the EICP's resistance to wind erosion, the hardness of the solidified layer, water retention, and resistance to rain erosion, while exhibiting a moderate degradation rate. In field experiments, KGMP-EICP exhibited a lower average daily TSP concentration than EICP after 30 days. Microscopic characterization revealed that KGMP resulted in a more uniform calcium distribution, regulated the preferential orientation of calcite crystals, and increased their crystallinity and grain size. In the molecular dynamics simulation, KGMP provided sites for the precipitation of calcium carbonate, which improved the probability of the combination of carbonate ions and calcium ions, and increased the average interaction energy between them by 521.27 Kcal/mol. The dust suppression mechanism of KGMP-EICP is that the soil fugitive dust forms a dense solidified layer of calcite under the regulation of KGMP. This study provides theoretical support and new strategies for the application of biomacromolecular functional materials in dust pollution control.