Removal of ammonia from wastewater
US4695387A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 1985 |
| Grant date | Sep 22, 1987 |
| Priority date | — |
| Expiry date | May 7, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F1/281
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process is disclosed for the continuous removal of ammonia from wastewater which converts the otherwise undesirable ammonia to a commercially useful end product such as ammonium phosphate. The process is carried out in an Advanced Separation Device which comprises a plurality of chambers moving about a circular path in periodic fluid communication with a plurality of fixed feed and discharge ports. The chambers are filled with a zeolite adsorbent which effectively adsorbs the ammonium ions contained in the wastewater at low pH levels but which, when contacted with an alkaline regeneration solution, releases the previously adsorbed ammonium in the form of ammonia gas, for which the zeolite has no affinity. By virtue of the ASD design, it is possible to add acidic materials to the wastewater in an intra-stage fashion i.e. during the adsorption step so as to optimize process efficiency. Similarly, intra-stage addition of alkaline materials during the regeneration step results in increased process efficiency. The process may be practiced with both industrial and municipal wastewaters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.