An Experimental Investigation of Microbial-Induced Carbonate Precipitation on Mitigating Beach Erosion

Abstract

Microbial-induced calcium carbonate precipitation (MICP) has the potential to be an envi-ronmentally friendly technique alternative to traditional methods for sustainable coastal stabilization. This study used a non-pathogenic strain that exists in nature to experimentally investigate the application of the MICP technique on mitigating sandy beach erosion. First, the unconfined compressive strength (UCS) test was adopted to explore the consolidation performance of beach sand after the MICP treatment, and then model tests in a wave flume were conducted to investigate the MICP ability to mitigate beach erosion by plunger waves. This study also employed field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS) to observe the crystal forms of MICP-treated sand after wave action. The results reveal that the natural beach sand could be consolidated by the MICP treatment, and the compressive strength increased with the increase in the cementation media concentration. In this study, the maximum compressive strength could be achieved was 517.3 kPa. The one-phase and two-phase MICP treatment strategies were compared of sandy beach erosion tests with various spray and injection methods on the beach surface. The research results indicate that the proper MICP treatment could mitigate beach erosion under various wave conditions; the use of MICP reduced beach erosion up to 33.9% of the maximum scour depth.