Wastewater treatment process
US6113788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1998 |
| Grant date | Sep 5, 2000 |
| Priority date | — |
| Expiry date | Nov 12, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/906
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A wastewater treatment process having improved solids separation characteristics and reduced biochemical oxygen demand (BOD) in the purified wastewater comprising the steps of: passing wastewater through a main aerobic biological oxidation zone and therein oxidizing a portion of the BOD a portion of the ammonia nitrogen content (NH.sub.3 --N); passing the effluent from said aerobic biological oxidation zone to an aerobic/mixing zone and therein mixing said effluent with effluent from the anoxic/anaerobic zone; passing the effluent from said aerobic/mixing zone to a settling zone and therein separating purified wastewater having reduced BOD and suspended solids, and sludge containing suspended solids; passing a portion of the sludge formed in the settling zone and volatile acids to an anoxic/anaerobic zone and therein increasing the extracellular polymer content of said sludge, the release of phosphorus into solution and the reduction of nitrate nitrogen to molecular nitrogen gas; and recycling an effective amount of the effluent from said anoxic/anaerobic zone to said aerobic/mixing zone. In an alternative embodiment, a volatile acid is added to a zone to which no additional oxygen…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.