FREMGANGSMAADE TIL OXIDATIV BIOLOGISK RENSNING AF SPILDEVAND

摘要

An oxydative biological purification process for waste water, comprising passing the waste water through an oxidation space containing aerobic activated sludge at such a rate, that the residence time in the oxidation space is between 0.3 and 20 h and a space load of COD of 4-50 kg/m<3> day and of nitrogen of at most 2.5 kg/m<3> is achieved, maintaining in the oxidation space a pH between 5 and 9 and substantially completely separating the purified waste water flowing out of the oxidation space from aerobic activated sludge and recycling the separated sludge into the oxidation space, the aerobic activated sludge being attached to a carrier and being separated from the waste water leaving the oxidation space by settling. …According to a preferred embodiment the settling tank is placed at a higher level than the oxidation space in order to avoid special provisions (e.g. recycle lines with pumps) and to save the floor space. …Preferably the aerobic activated sludge is attached to sand having an average granular size between 0.1 and 2 mm. …The purification is preferably carried out at a temperature of 10-60 DEG C. …The process enables a reliable waste water purification, even when the COD of the waste water is strongly varying and even when varying amounts of waste water are available, and supervision by skilled persons is practically not necessary.