Researchers from Northwestern University have demonstrated a groundbreaking technique to combat coastal erosion using mild electrical currents. This innovative method, inspired by marine organisms, could provide a lasting and eco-friendly solution to protect global coastlines against the threats of climate change.
New research from Northwestern University has revealed a groundbreaking technique that could revolutionize coastal protection against erosion caused by climate change and rising sea levels. The study, published in the journal Communications Earth and Environment, details how a mild zap of electricity can transform seawater-soaked sand into a rock-like solid, potentially safeguarding coastlines for generations.
Inspired by shell-forming sea creatures, the researchers utilized naturally dissolved minerals in seawater to create a natural cement, binding sand grains without requiring traditional construction materials. Unlike mollusks that use metabolic energy, the scientists harnessed electrical energy to initiate the chemical reaction, thereby addressing both economic and environmental challenges in coastal protection.
“Over 40% of the world’s population lives in coastal areas,” lead author Alessandro Rotta Loria, the Louis Berger Assistant Professor of Civil and Environmental Engineering at Northwestern’s McCormick School of Engineering, said in a news release. “Because of climate change and sea-level rise, erosion is an enormous threat to these communities. Through the disintegration of infrastructure and loss of land, erosion causes billions of dollars in damage per year worldwide.”
Traditional methods to combat coastal erosion, such as constructing sea walls or injecting cement into the ground, are costly and often fail to provide long-lasting solutions.
“Sea walls, too, suffer from erosion,” Rotta Loria added. “Injecting cement and other binders into the ground has a number of irreversible environmental drawbacks. It also typically requires high pressures and significant interconnected amounts of energy.”
Rotta Loria’s team devised a technique leveraging mild electrical currents to induce mineral formation. These minerals, when interacting with sand, act as a binding agent, converting the sand into a robust and durable structure.
“After being treated, the sand looks like a rock. It is still and solid, instead of granular and incohesive,” Rotta Loria added. “The minerals themselves are much stronger than concrete, so the resulting sand could become as strong and solid as a sea wall.”
This innovative approach could not only protect coastlines but also offers a cost-effective alternative to traditional methods, estimated to be just $3 to $6 per cubic meter of electrically cemented ground compared to up to $70 for conventional methods.
The study indicates significant potential for widespread applications, from stabilizing sand dunes to reinforcing existing marine structures.
“We can use it to strengthen the seabed beneath sea walls or stabilize sand dunes and retain unstable soil slopes,” said Rotta Loria. “The applications of this approach are countless.”
Going forward, the team plans to test this technique in real-world coastal settings, aiming to validate laboratory results in dynamic marine environments.
Supported by the Army Research Office and Northwestern’s Center for Engineering Sustainability and Resilience, this research points towards an eco-friendly, efficient and sustainable solution to one of the most pressing environmental challenges of our time. As coastal communities worldwide face the increasing threat of erosion, Rotta Loria’s innovative method provides a beacon of hope for more resilient and sustainable coastal infrastructure.