Enzyme-induced carbonate precipitation utilizing fresh urine and calcium-rich zeolites

Enzyme-induced carbonate precipitation (EICP) is a biocementation technique that produces comparatively fewer carbon dioxide emissions than traditional cementation. However, the use of synthetic reagents for EICP costly, and process an ammonium byproduct water pollutant. This study utilized fresh human urine as source urea calcium-rich zeolites adsorbent calcium ions cementation technique. Batch hydrolysis, adsorption, experiments were conducted to determine effects zeolite type, form (i.e., exchangeable ion), release. The results showed chabazite adsorbed comparable released 2.7-times more on average clinoptilolite; also in excess without addition chloride solution. Additionally, synthetic-fresh real-fresh had adsorption release trends. Finally, inclusion pre-hydrolysis step reduced by 3.9-times; additionally, longer times led CaCO 3 outside sand column, which undesirable outcome soil biocementation. Even with this limitation, content columns ranged from 0.48% 0.92%, signifies potential proposed cementation, given higher initial concentration urea. work show ability both waste stream, urine, naturally occurring material, zeolites, greatly reduce economic environmental stressors conventional binders applications such liquefaction mitigation (e.g., Portland cement) dust suppression polymers). • Conversion Ca resulted improved NH 4 + adsorption. Calcium-form 2+ applications. Precipitation undesirably occurred column. was produced but did not cement together columns. Fresh viable EICP.