(eli5) How is water treated and what does it mean when a water bottle says “purified by reverse osmosis” ?

Question

(eli5) How is water treated and what does it mean when a water bottle says “purified by reverse osmosis” ?

In: Chemistry

Answer 1

Reverse osmosis is where water is cleaned by either pushing it or pulling it through a membrane. The membrane has tiny holes that are large enough for water to pass through but are too small for dirt and other particles.