To understand the innovation of their proposal, it’s necessary to have some context, starting with the process used to purify water in the most modern desalination plants. Let’s dive in. We begin with a physical phenomenon, osmosis, where if two liquids with different concentrations of solutes (salt in this case) are separated by a semipermeable membrane, the liquid with the lower concentration tends to pass through the membrane to mix with the one with the higher concentration. If we are talking about saltwater on one side and freshwater on the other, the freshwater—which has the lower concentration—would tend to flow towards the saltwater.
However, in desalination plants, the goal is the opposite: to reduce the salinity of the saltwater, not to increase the salinity of the freshwater. So, they reverse the osmosis process. How? By using pressure pumps to push the liquid with the higher concentration, forcing the saltwater, against natural laws, to pass through the membrane and leave the salt behind.
