So how many stars are there in the Universe? It is easy to ask this question, but difficult for scientists to give a fair answer! Stars are not scattered randomly through space, they are gathered together into vast groups known as galaxies. The Sun belongs to a galaxy called the Milky Way.
Reverse osmosis. Reverse osmosis (RO) is a water purification technology that uses a semipermeable membrane to remove ions, molecules, and larger particles from drinking water.
Reverse Osmosis Treatment for Drinking Water. Other fact sheets in this series identify reverse osmosis, commonly called RO, as a treatment process for. removing many different contaminants. RO is more generally used for small volumes of drinking water. This document provides greater detail concerning RO treatment.