Process for biological purification of waste water by trickling over bacterial beds and device employed.

摘要

Process for biological purification of waste water. This process comprises a stage of purification of the waste water and, when the packing material 2 becomes too blocked, the waste water distributed by the perforated feed pipe 3 is replaced by a cleaning solution containing at least 7 g/l of ammonium ions and preferably a solution of aqueous ammonia and ammonium chloride taken from the vessel 8 by the pump 10 and overflowing through flexible pipes 12 at the top of the packing 2. The process according to the invention makes it possible to unblock the packing material in situ without moving the said material. <IMAGE>