Cementing Marine Sands Wetted with Chemically Distinct Seawaters via Electrodeposition

Coastal erosion poses significant challenges to marine ecosystems and infrastructures worldwide. Conventional mitigation methods, such as concrete barriers and beach nourishment, lack sustainability and long-term effectiveness, and underscore the need for innovative approaches. This study examined the potential of electrodeposition as a novel method for mitigating coastal erosion, focusing on the electrically mediated precipitation of mineral binders within the pore space of marine sediments wetted by seawaters with varying chemical compositions. Laboratory experiments were conducted on silica sand saturated with seawater to assess the effects of salt concentration and the calcium-to-magnesium ratio on the type, morphology, and distribution of precipitated minerals. The results demonstrate that electrodeposition effectively bonds soil particles across a broad spectrum of seawater chemistries found in natural marine environments. The results suggest that high salt concentrations promote the deposition of magnesium hydroxide, whereas higher calcium-to-magnesium ratios favor the formation of calcium carbonate, primarily calcite. These mineral deposits alter soil microstructure, reduce porosity and hydraulic conductivity, and enhance soil strength. The adaptability of electrodeposition to varying seawater chemistries highlights its potential for geotechnical applications, such as soil erosion control and stabilization in various marine areas. This study contributes to the development of a sustainable and innovative approach for mitigating coastal erosion and strengthening marine sediments in the face of the challenges posed by sea- level rise, extreme weather events, and climate change.