Construction of Water Pond Using Bioslurry-Induced Biocementation

This paper presents a methodology to construct a water pond in sand using bioslurry layer via the microbially induced carbonate precipitation (MICP) process. Bioslurry is calcium carbonate crystals containing high-urease active bacteria cells, allowing further microbially induced calcium carbonate precipitation when introducing cementation solutions (urea and calcium ions). With the effect of a top sand layer, the daily seepage rate of the water pond was dramatically reduced to 3 mm/day through four rounds of treatments with 1.6 M of cementation solution. In this way, a bioslurry-based waterproofing layer was formed for the construction of a water pond. Due to the bonding strength gained from calcium carbonate crystal precipitation, the flexural strength of bioslurry layer was in the range of 3.6-4.2 MPa. This is sufficient to support the hydrostatic pressure and avoid bending for water pond. With the low seepage rate and high flexural strength, the proposed bioslurry layer is a promising method for the construction of a fishpond in sand; other potential applications include stabilization of sand dunes and concrete healing.