“When the well is dry, we learn the worth of water.”
Benjamin Franklin
  Water is a chemical substance with the chemical formula H2O. Its molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state, water vapor or steam.  
Reverse Osmosis Systems

Reverse Osmosis Systems

Reverse osmosis is a process that industry uses to clean water, whether for industrial process applications or to convert brackish water, to clean up wastewater or to recover salts from industrial processes.

Reverse osmosis will not remove all contaminants from water as dissolved gases such as dissolved oxygen and carbon dioxide not being removed. But reverse osmosis can be very effective at removing other products such as some pesticides, solvents and other volatile organic compounds.

RO is when a pressure is applied to the concentrated side of the membrane forcing purified water into the dilute side, the rejected impurities from the concentrated side being washed away in the reject water. RO can also act as an ultra-filter removing particles such as some micro-organisms that may be too large to pass through the pores of the membrane.