Theprocess of water purging must be efficient(as simple as possible), environmentally friendly and should not consumemany resources(such as energy and chemical compounds). 1.Ultrafiltration Prior toall other water treatment stages, water will be filtered. The main scope ofultrafiltration is to eliminate the macromolecules(algae, organic molecules,germs, bacteria, viruses), that could cumber the Reverse Osmosis process. Thisaction doesn’t require a high amount of energy and the water becomes clear atthe end. This stage can not, however, get ridof dissolved salts, nor of ionized contaminants and solvents, so that’s why theother stages are still very important. 2.
ReverseOsmosis In this stage, dissolved minerals, metals, salts, fluoride and evenpyrogens are eliminated. At low pressure, the process generates a relativelybig amount of waste water; However, the water loss can be minimized by usinghigh pressure instead of a lower one. Reverse Osmosis is efficient whenthe entering water is clear and free of microorganisms(these two aspects areachieved in the Ultrafiltration). After this stage, water loses almostall its minerals and it has acid pH. 3.UV Light Action This stage is also known as photooxidation and it requiresa small amount of energy. It separates electrons from the molecules and it iscreating free radicals that alter the structure of toxic agents.
After stage 1 and 2 of water treatment, water isclear, so the UV light can reach every corner of the water tank. If there isstill some bacteria left in the water, it is deactivated by this process. 4.ElectrodeionizationThis water treatment technic is used as a polishingprocess after Reversed Osmosis. Electric current is applied in order for theions to move toward the electrodes(cathode and anode). The ions don’t arrive tothe specific electodes because they can’t get through the ion-selectivemembrane that is fixed in their way. They concentrate on one side of themembrane and they are eliminated from the system. The waterbecomes ions-free and it splits into OH- and H+ and the water treatment processcontinues.
5.ActivatedCarbon Filters This process eliminates organic chemicals(andcarbon-based substances) and even VOCs. It also gives the water a natural goodtaste and odors are removed.The AC beds might be able to shelter bacteria, that’swhy the microorganisms were killed before reaching this module (thedeactivation of the bacteria was done in the ultrafiltration and UV lightmodules).