Method for purification of water which has been used for vehicle wash

摘要

Water which has been used for vehicle wash is collected in a first tank (1) for purification of the same. The wash water contains contaminants as particles and oil. From the tank (1) a flow of wash water is withdrawn which is mixed with a flocculent consisting of a high molecular cationic polymer and a coagulant consisting of a metal salt, which is environmentally friendly. The most part of the solid particles are separated in a filter (6) and the purified wash water is directed further to a second tank (7). From this a partial stream is withdrawn continuously/alternatively during a certain time, which is brought to pass a centrifugal separator (9). The purified wash is returned to the mentioned second tank (7) and is used again for vehicle wash.