Bio-Gel Formation Through Enzyme-Induced Carbonate Precipitation for Dust Control in Yellow River Silt

Area of Science:

• Geotechnical Engineering
• Environmental Science
• Materials Science

Background:

• Dust suppression is crucial for Yellow River silt, prone to wind-rain erosion.
• Existing methods often lack long-term efficacy or sustainability.
• Enzymatic carbonatogenesis offers a promising bio-mineralization approach.

Purpose of the Study:

• To explore gel-like polymeric matrices formation via carbonate precipitation for dust control.
• To investigate the efficacy of a hydrogel-modified enzymatic carbonatogenesis (EICP) method.
• To optimize the EICP process for enhanced soil stabilization and erosion resistance.

Main Methods:

• Utilized urea and CaCl2 for calcium carbonate (CaCO3) precipitation.
• Optimized cementation solution concentration at 1.25 mol/L (equimolar).
• Applied a spraying volume of 4 L/m2 with sequential urea-CaCl2 and urease solutions.
• Analyzed crust properties using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD).

Main Results:

• Achieved a 14.9 mm thick hybrid gel-CaCO3 crust with compressive strength over 752 kPa.
• Demonstrated enhanced resistance to wind-rain erosion and mechanical wear.
• SEM confirmed synergistic interaction: hydrogel as nucleation template, enhancing crystal bridging and pore filling.
• XRD validated the formation of a stable gel-CaCO3 composite structure.

Conclusions:

• Gel-enhanced EICP provides a novel, sustainable bio-gel composite technology for dust mitigation.
• The method significantly improves the mechanical strength and durability of silt soils.
• This approach offers a promising solution for controlling dust in arid and semi-arid environments.