Biological wastewater purification with a downstream precipitation stage
Patent 5075007 Issued on December 24, 1991. Estimated Expiration Date: 
May 25, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 25, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3440165 3440166 3623975 Process of preparing sewage sludge for dewatering Process for the disposal of sewage Waste disposal treatment of calcium-containing organically loaded wastewaters Patent #: 4227998 InventorsAssigneeApplicationNo. 528508 filed on 05/25/1990US Classes:210/604, And reusing oxidant210/614, Controlling process in response to stream constituent or reactant concentration210/621, Recirculating to prior step210/627, Utilizing specific oxidant, other than air alone (e.g., oxygen-enriched air, ozone, peroxide, etc.)210/631, And additional treating agent other than mere mechanical manipulation (e.g., chemical, sorption, etc.)210/711, For recovery of a treating agent210/716, Including step of manufacturing inorganic treating agent210/906Phosphorus containingExaminersPrimary: Wyse, Thomas G.Attorney, Agent or FirmInternational ClassC02F 003/26Foreign Application Priority Data1989-05-29 DEAbstractWastewater containing impurities refractory to secondary treatment is first introducted into an aerobic biological treatment stage operating with an oxygen-enriched stream and subsequently into a precipitation stage where the biologically treated wastewater is combined with Ca(OH)2 to precipitate Ca(OH)2 CaCO3 sludge which adsorbs or occludes impurities. The clear liquid, separated from the resultant sludge, is passed to a second precipitation stage where it reacts with a CO2 and oxygen-containing waste gas at least in part from the aerobic biological treatment stage, thereby forming additional CaCO3. Waste gas withdrawn from the second precipitation stage, being enriched in oxygen is recycled to the aerobic biological treatment stage.Field of SearchIncluding collecting or storing gas (e.g., fuel, carbon monoxide, etc.)And reusing oxidant Controlling process in response to stream constituent or reactant concentration Recirculating to prior step Utilizing gas, water, or chemical oxidizing or reducing agent Utilizing organic regenerant Rehabilitating or regenerating in diverse zone or chamber Continuous cyclic process Using conserved or recirculated fluid And additional treating agent other than mere mechanical manipulation (e.g., chemical, sorption, etc.) Treating the insoluble substance For recovery of a treating agent Including recycling Of separated solids Seeding Including step of manufacturing inorganic treating agent In situ Including degassing Phosphorus containing | |
