Solution decontamination method using precipitation and flocculation techniques
US5330658A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1993 |
| Grant date | Jul 19, 1994 |
| Priority date | — |
| Expiry date | Mar 17, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/914
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Solutions such as for example groundwater, drinking water, extracting solutions and effluents contaminated with metals, radioactive species and organics, singly or in combination, are treated by first removing undesirable oxidizing agents from the contaminated solution. Then the contaminated solution is separately treated with aqueous solutions of ferrous sulfate and hydroxide, which precipitate substantially all of the contaminants. Next, the precipitate is treated with a flocculant and/or a coagulant to form an easily dewaterable and separable solid. The solid contaminants are readily removed from the cleansed solution. The process utilizes a novel combination of steps which maximizes contaminant removal, minimizes waste volume, and produces a recyclable solution and a manageable waste stream. The preferred hydroxide solutions are sodium hydroxide, calcium hydroxide, and ammonium hydroxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.