Patent DE-102008030809-A1 (DE)
Title: Method for water recovery and/or cleaning of wastewater, by carrying out pressure less biologically active step in a self-tensioning, finely-meshed mesh for self-effacement of coarse material, which is washed for avoiding faecal sludge
IPC: C02F3/20
Filed: 2008-06-28
Abstract: The method comprises carrying out pressure less biologically active step in a self-tensioning, finely-meshed mesh (2) with a mesh size of smaller than 5 mm for self-effacement of coarse material, which is washed for avoiding faecal sludge from biologically pre-cleaned wastewater. The wastewater is passed through in a cascade-like operation of three separate, biologically active steps. The wastewater is reduced from the undissolved portion of the oversize material. The wastewater with particle size of smaller than 5 mm is subjected over a cross-flow cleaning in the area external of the mesh. The method comprises carrying out pressure less biologically active step in a self-tensioning, finely-meshed mesh (2) with a mesh size of smaller than 5 mm for self-effacement of coarse material, which is washed for avoiding faecal sludge from biologically pre-cleaned wastewater. The wastewater is passed through in a cascade-like operation of three separate, biologically active steps. The wastewater is reduced from the undissolved portion of the oversize material. The wastewater with particle size of smaller than 5 mm is subjected over a cross-flow cleaning in the area external of the mesh for denitrification with anoxic milieu. The biologically active bacteria sludge and completely nitrified wastewater are led with nitrate oxygen. The nitrate is converted into gaseous nitrogen through denitrification and the biologically degradable carbon is converted into carbon dioxide. The wastewater is completely freed from nitrogen compounds. A further denitrification reaction is reached by alternate aeration and by minimizing the air entry. The entry of oxygen in the air is controlled over a filtrate quantity measurement. A physically technical bleaching and hygienisation are carried out after physical elimination of all biologically non-degradable substances over ultrafiltration membrane. The wastewater flows out from the first container (3, 7, 9) or basin/first hollow chamber either in the free mirror in the following biological area and is brought in corresponding height difference through pumps on the level of the biological area. A pump is required for simple maintenance external of the network in the denitrification area. The inflow is carried out in the biological area in the free mirror and the reaction pump is present in the second or later container or basin. The pump in each case guarantees sufficient recirculation of the wastewater and upstream denitrification. The resultant filtrate is brought either hydrostatically or over a further self suctioning conveyor unit (4) with slight low pressure to the utilization grade. The membrane in the requirement is automatically washed back without restriction of the operation of the plant directly during the operation with chemicals or filtrate. In the first step, the carbon decomposition is carried out with biological heavily degradable substances like hormones and endocrine material and is integrated over the biological phosphate elimination and also an alkaline and acid phosphate precipitation, which is regulated over the filtrate quantity and pH value. In the second step, the biological non-degradable substance and the complete bleaching are carried out through the physical elimination (adsorption over active charcoal, adsorber resin or aluminum silicate) with subsequent additional physical hygienisation with UV radiation. An INDEPENDENT CLAIM is included for a device for water recovery and/or cleaning of wastewater.