THE FIELD TRIP

The other week, our science class went to a “desalination plant” in San Pedro del Pinatar and we were taught about the “osmosis” and “reverse osmosis” processes. The difference between osmosis and reverse osmosis is the following one:

Osmosis is an important biological phenomenon for the physiology of the living cell. The phenomenon of osmosis is based on the search for balance. When two fluids come into

contact with different concentrations of dissolved solids, concentrations mix until uniform. If these fluids are separated by a permeable membrane (which allows the passage there through of a fluid), the fluid moves through the membrane in the lowest concentration so that fluid passes to the highest concentration.After a while the water content is higher on one side of the membrane. The difference in height between the two fluids is known as osmotic pressure.Reverse Osmosis: If using a pressure above the osmotic pressure, the opposite occurs. Fluids are pressed through the membrane while dissolved solids stay behind.

This is the osmosis process (balance of salts) This is the reverse osmosis (salty water to pure water)

Here we present an illustrative graphic:

By Carlos Owen Leal ( 4º A ESO)