Process for removing monohydric and polyhydric phenols from waste water
US4025423A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 1976 |
| Grant date | May 24, 1977 |
| Priority date | — |
| Expiry date | Jan 9, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2001/007
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Monohydric and polyhydric phenols are removed from waste water together with hydrogen sulfide, free and combined ammonia, by extraction and distillation. The waste water is formed during the degasification or gasification of coal and is subsequently subjected to biological purification. The steps of the process are as follows: PA1 1. Removing a major portion of the monohydric phenol, part of the polyhydric phenol and any free fatty acids present in the waste water by extraction with a small amount of a non-saponifying organic solvent having a boiling point below 100.degree. C; PA1 2. separating the phenols from the extract by distillation; PA1 3. Removing a major portion of the polyhydric phenols, the remaining monohydric phenols and any free acids by a single or repeated extraction with a large amount of the same organic solvent from the refine phase from step (1). PA1 4. Transforming the phenols in the extract from step (3) to their salts by treatment with an aqueous alkaline solution, washing the salts out and separating the mixture into an organic phase and an aqueous phase; PA1 5. Recycling the solvent-containing organic phase from step (4) to step (3); PA1 6. Recovering the f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.