Zapping beaches with electricity can produce “natural cement where we need it most. Coastlines are washing away, but a surprising technique could make grains of sand stick together and prevent erosion.
We have just witnessed the destructive force of a major hurricane – in this case Hurricane Helene. With massive power outages, fallen trees and power lines, flooding, damaged and destroyed homes, and personal property, we also saw houses near the water being torn apart by the storm surge and violent waves, and moved off their foundations. As we have discussed several times, with continuing sea level rise, over time this will become a much more common occurrence. “Alessandro Rotta Loria, an assistant professor at Northwestern University, noted in a statement that around 40% of the world’s population lives in coastal areas, and rising sea levels pose “an enormous threat to these communities.”
What I found fascinating was that “to find a solution Loria and his team took inspiration from marine organisms like clams and mussels, which use their metabolic energy to convert seawater minerals into their skeletons and shells. Rotta Loria decided to a different energy source, in the form of electric shocks.” And also, “[b]ecause seawater contains a great number of dissolved minerals, as well a high number of ions, adding the charge can generate two common minerals: magnesium hydroxide and calcium carbonate. The latter is the primary material found in mollusk shells, while the former is common in many stones.”
“My aim was to develop an approach capable of changing the status quo in coastal protection—one that didn’t require the construction of protection structures and could cement marine substrates without using actual cement,” said Rotta Loria. The team tested alterations of power and they “discovered there only needed a mild current of 2 or 3 volts to get what they were looking for: a material with the properties of a natural cement, holding sand particles together.” After the treatment, the sand looks like a rock.
In a study published in the journal Communications Earth and the Environment, Rotta Loria described experiments where electrical charges were applied to sand submerged in seawater. The team messed around with different voltages, the length of time voltages were applied to the sand, the density of the soil, and other variables. They found that while altering the power they used would alter the exact ratio of the minerals that were produced, they ultimately only needed a mild current of 2 or 3 volts to get what they were looking for: a material with the properties of a natural cement, holding sand particles together.” And because the voltage was so low it wouldn’t create any danger to coastal sea life. “The applications of this approach are countless,” Loria aid. “We can use it to strengthen the seabed beneath sea walls or stabilize sand dunes and retain unstable soil slopes. We could also use it to strengthen protection structures, marine foundations and so many other things. There are many ways to apply this to protect coastal areas.”
Like most of the amazing technological advances we are seeing, this team will have to find ways to scale up and finance this technology for practical applications. But it looks like a good start.
Sources:
https://gizmodo.com/zapping-beaches-with-electricity-can-produce-natural-cement-where-we-need-it-most-2000489902
https://news.northwestern.edu/stories/2024/august/fighting-coastal-erosion-with-electricity/?fj=1
Photo by Anna Tarazevich: https://www.pexels.com/photo/seashells-with-green-stone-on-white-sand-6512253/
