Biocementation for beach erosion control using seawater extracted soybean enzyme

Beach erosion is a major challenge for coastal cities like Singapore. This is increasingly the case with greater impact from climate change and sea level rise. One of the new approaches in improving beach erosion resilience is biocementation using enzyme-induced carbonate precipitation (EICP). A field study was carried out using an EICP method with crude urease enzyme extracted from soybean. A simplified urease enzyme extraction procedure was developed to use seawater as the solvent. The use of seawater and a modified coarse filtration method enabled the enzyme extraction process to be done on site at an accelerated rate. A hybrid biogrout infiltration technique was also adopted on site to overcome the accumulation of unfavourable bioclogging effect. After the treatment, the strength of the treated slope surface increased to a maximum value of 2 MPa. The field tests also indicated that the simplified EICP method not only increased the resistance to wave or rainwater erosion but also facilitates the grass growth on the treated beach. This unique feature enables the proposed method to be an eco-friendly method too.