Experimental Study on Optimization of Cementation Solution for Wind-Erosion Resistance Using the MICP Method

In the present study, an environmentally friendly microbial-induced calcium carbonate precipitation (MICP) technique was explored to reinforce the desert sand using the stopped-flow pouring method. A detailed experimental study has been conducted with Sporosarcina (S.) pasteurii urease-producing bacteria with a 0.5 M cementation solution. To optimize the cementation solution, three different pore volumes (PV), i.e., 0.4, 0.6, and 0.8, were considered. The cementation solution was provided every 24 h and considered as one treatment cycle. The cylindrical specimen in three replicas was biotreated for 7, 14, and 21 days in 1:1 and 1:2 (diameter: height) ratios for determina-tion of split-tensile strength (STS) and unconfined compressive strength (UCS), respectively. Micro-structure characterization of untreated and biotreated sand was also examined using a scanning electron microscope (SEM) and energy-dispersive X-ray analysis (EDX). Rocklike behavior was ob-served for biotreated-sand samples using the UPV test. Test results for 21 days with 0.8 PV were 1340 kPa, 241 kPa, and 1762 m/s for UCS, STS, and UPV, respectively, with an average calcite content of 16.2%. Overall, the 0.5 M cementation solution with a 24 h treatment cycle, 0.8 PV with 7 days, and 0.4 PV with 14 days gave optimum treatment solution, and showed heavily cemented and rock-type behavior of the biotreated-sand sample.

Automated summary

In this study, an environmentally friendly microbial-induced calcium carbonate precipitation (MICP) technique was used to reinforce desert sand using the stopped-flow pouring method. Experimental results showed that biotreatment with urease-producing bacteria and cementation solution significantly improved the strength of the sand and exhibited rock-like behavior.