The Purification Process
The recycled water first goes through microfiltration, an initial filtration process where water is pumped through tubes filled with tiny membranes. Each membrane is made up of hollow fibers, perforated with holes 1/300th the width of a human hair. Solids, bacteria, protozoa, and some viruses are removed from the water as it is drawn through the tubes.
2. Reverse Osmosis
The water then goes through a process called reverse osmosis where it is forced under high pressure through membranes with holes so small that a water molecule is almost the only substance that can pass through. As a result, things such as salts, viruses, and most pharmaceuticals, personal care products and pesticides cannot pass through the membranes and are left behind. This is the same process that is used by some bottled water companies, baby food manufacturers, and for kidney dialysis.
3. Ultraviolet Light
Ultraviolet Light (UV) with advanced oxidation is a further safety process where extremely concentrated light, similar to the sun's rays, kills any organisms that may remain after reverse osmosis. UV combined with hydrogen peroxide (H2O2), similar to strong bleach, is an effective disinfection process that keeps trace organic compounds from reaching drinking water supplies.