The use of prokayotes and other organisms to clean up pollutants from soil, air, or water is called Bioremedation. Bioremedation is the use of living organisms for the recovery or cleaning up of a contaminated medium such as soil, sediment, air and water. It is actually a waste management technique that neutralizes pollutants from contaminated site using organisms. examples of bioremedation related technologies are mycoremedation, phytoremedation among others.
Osmosis! Osmosis is the process that water diffuses across the plasma membrane.
That would be the sun. Hope this helps.