Bench-Scale Feasibility Testing of EICP Treatment for Runoff Erosion Control

The end goal of this research is to develop a method for controlling runoff erosion in the sandy, sloping ground using enzyme induced carbonate precipitation (EICP). The EICP is a soil improvement technique that uses urea hydrolysis catalyzed by urease enzyme to precipitate calcium carbonate and cement soil grains. This paper describes an experimental feasibility study at the bench scale of EICP-treated sands under simulated rainfall and 3H:1V slope. Two natural poorly graded clean sands were tested. Block specimens were used to compare the cementation obtained with laboratory-grade urease and crude extract urease. Plot specimens were used to assess the mass loss under rainfall intensities of 76.2 and 114.3 mm/h in 20-min simulated rain events. The level of cementation of the specimens prepared with the crude extract was similar to the cementation obtained with laboratory-grade enzyme. The results of the preliminary bench-scale test showed that the EICP treatment has potential to reduce considerably the soil erosion. Future work will consider larger plot sizes, revised test setup, and greater rainfall intensity and/or droplet size.