Method for removal of heavy metals from water
US6153108A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1998 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Jun 11, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/914
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method to remove heavy metals concentrations in water down to very low levels is described. The method calls for the addition of a soluble sulfide to the water. This is followed adding a soluble iron reagent such as ferrous sulfate or ferrous chloride. The water is aerated. As an alternative to aeration, the pH of the water can be increased. Finally, the solids generated from the above steps are separated from the water. This method has been shown to remove heavy metals, particularly copper and zinc, from actual industrial wastewater to very low concentrations, i.e., below about 100 ppb. Furthermore, the treated water is free of sulfide. The byproduct sludge comprises iron sulfide, iron oxides, iron hydroxides, and the heavy metal sulfides.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.