Method of removing heavy metals from industrial waste streams
US4343706A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1980 |
| Grant date | Aug 10, 1982 |
| Priority date | — |
| Expiry date | Aug 4, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/913
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Heavy Metals contained in industrial waste streams are removed therefrom by flocculation using a source of ferric ions and an alkaline material at a basic pH. Both the flocculated heavy metals and the coagulant chemicals are recovered by acidifying the floc to a pH of between 3.2 and 3.7. This liberates the heavy metals back into solution but does not destroy the floc particles. After separation and removal of the concentrated heavy metal solution, the floc is further acidified to completely dissolve it. This dissolved ferric ion containing solution may then be reused to treat succeeding portions of heavy metal containing waste streams. The concentrated heavy metals solution may also be recycled or the metals contained therein recovered for reuse or disposed of in an acceptable manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.