Process and apparatus for the biological purification of phosphate-containing wastewater
US4460470A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 23, 1983 |
| Grant date | Jul 17, 1984 |
| Priority date | — |
| Expiry date | Feb 23, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/906
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
This invention relates to a process for the biological purification of phosphate-containing wastewater wherein the wastewater is gas-treated, i.e. aerated, in an oxygenation tank in the presence of activated sludge for degrading organic hydrocarbon compounds and absorption of phosphate by microorganisms present in the activated sludge. The wastewater-activated sludge mixture is then withdrawn from the oxygenated tank and divided, in a post clarification stage, into purified, essentially phosphate-free water and phosphate-containing sludge. The phosphate-containing sludge is recycled, at least in part, into the oxygenation tank. A partial stream of wastewater-activated sludge mixture is branched off from the oxygenation tank, and/or recycle sludge is branched off as a partial stream from the post clarification stage, and the mixture is subjected to flotation treatment for thickening. A thus-obtained, low-phosphate flotage, i.e. subnatant liquor, is discharged from the flotation unit. Likewise, resultant, phosphate-rich flotage sludge, i.e. thickened floating sludge, is discharged and heated, and after this heating, is treated anaerobically and mixed with wastewater to be purified. S…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.