Hydrogel-Assisted Enzyme-Induced Carbonate Mineral Precipitation

Abstract

AbstractBenchtop experiments demonstrate the promise of hydrogel-assisted enzyme-induced carbonate precipitation (EICP) as a means of enhancing EICP for soil stabilization. Enzyme-induced carbonate precipitation uses hydrolysis of urea (ureolysis) catalyzed by the urease enzyme to precipitate CaCO3 in the presence of urea and calcium in a water-based solution. Xanthan and guar gum biopolymers and an inert polyol-cellulose hydrogel were used to assess the ability of a hydrogel to enhance EICP by retaining reaction product around the soil particles. The experiments were conducted in sand-filled paper cups and soilless glass beakers at 1.66 and 0.33 M of initial calcium chloride (CaCl2) concentrations using high-activity and low-activity plant urease. Ureolysis and CaCO3 precipitation occurred in all hydrogel-assisted EICP tests, suggesting that the hydrogels used in this study do not interfere with EICP. Furthermore, hydrogel-assisted EICP appeared to retain moisture for extended periods of time and reduce ...