Rather than simply using chlorine to kill viruses and bacteria, the H2OpenDoors project chooses to remove the pathogens from the water altogether with membrane technology.
There are four primary methods of filtration, defined by pore size of the membranes they use. Water must be pressed through the pores, leaving particulates on the outside of the strands as purified water pushes into the hollow chamber and out the ends. Reverse Osmosis is the process that takes everything out of the water, including dissolved salts. That’s good news, and bad news. RO treatment produces acidic distilled water, stripped of any essential minerals or electrolytes. For most of the applications where we work, the poor need healthy water at an affordable price. RO is quite common in bottled waters, but the bottlers add the electrolytes, salts and minerals in for taste and health. This makes the water too expensive. RO also wastes about 50% of the water pressurized to squeeze through the holes, so it is the least “green” of technologies.
Nanofiltration isn’t much better and is almost as wasteful. We choose Ultrafiltration as the appropriate membrane technology. With pores smaller than human-harmful viruses, bacteria and microscopic parasites, the SunSpring’s membrane pore size is 20 nanometers in size, or 0.02 micron. Water is pressurized at 40 psi, using 97% of the water source. Electrolytes and other essential minerals are preserved in the purified water, while the toxins are removed. In the rare cases where high levels of dissolved toxins must be removed, such as fluoride or arsenic, the SunSpring’s housing can accommodate additional media to finish and dispense perfect drinking water.