Method for removing ammonia nitrogen in coking wastewater
US8329040B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 2008 |
| Grant date | Dec 11, 2012 |
| Priority date | — |
| Expiry date | Jul 30, 2029 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2103/365
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A new method for removing ammonia nitrogen in coking wastewater is disclosed in this invention. It comprises steps as follow: introducing coking wastewater into a reaction pool into which magnesium and phosphate are added; adding sodium hydroxide to regulate the PH of the mixture around 9.0-10.5; separating the supernatant and the precipitate after proper agitation and natural precipitation; dehydrating the precipitate and then adding alkaline fly ash, water to the dehydrated precipitate and stirring the mixture; decomposing the mixture with heating and absorbing the ammonia gas thereof produced with acidic solution. In consideration of high concentration of ammonia nitrogen in coking wastewater, this invention aims at quick and efficient treatment. The concentration of ammonia nitrogen in treated water meets the highest discharge standard stipulated in [China National] Integrated Wastewater Discharge Standard (GB8978-96). Meanwhile, this invention provides a new way for beneficial utilization of the alkaline fly ash as well. The chemicals adopted for wastewater precipitation in this invention can be recovered for recyclable use, which consequently cuts down the total cost of the w…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.