Method for removing nitrogen from wastewater
US5776344A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1995 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Oct 26, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/903
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A process and apparatus for treating wastewater containing nitrogen compounds is disclosed. The process includes passing the wastewater to be treated through a biologically active material in one direction to treat the wastewater and passing the treated wastewater through the biologically active material in a second direction to further treat the wastewater under alternating aerobic and anoxic conditions, converting nitrogen compounds to nitrates and nitrites, and converting nitrates and nitrites to gaseous nitrogen. The apparatus includes a mixing tank that includes an upper equalization area and a lower sludge settling area, a filtration tank containing the biologically active material in communication with the mixing tank, an adjustable aeration inlet supplying air to the filtration tank under aerobic conditions and eliminating or reducing the supply of air to the filtration under anoxic conditions, and a clearwell in communication with the filtration tank for recirculating treated wastewater or discharging the treated wastewater.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.