Reverse osmosis is a process of separating dissolved substances in solution by forcing a current of water through a semipermeable membrane under pressure. Which will allow the molecules to pass through, while the larger molecules remain in the flow and impurities are left behind. They use this technology to make clean drinking water, remove fluoride from tap water, filter wastewater (sewage), refine sea water, desalinate seawater, produce distilled or demineralized water for human consumption and industrial uses.