Method for recycling sludge during waste-water treatment
US7285222B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 2005 |
| Grant date | Oct 23, 2007 |
| Priority date | — |
| Expiry date | Feb 3, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/913
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method for recycling sludge during waste-water treatment firstly utilizes a process of chemical coagulation to produce sludge rich in copper ions. The sludge is then leached in a sulfuric acid storage tank with sulfuric acid of concentration 1-2N, whereby a extractive solution with copper enrichment 18-39 g/L and residues can be obtained. The extractive solution is then processed in a refrigeration crystallization tank to form copper sulfate crystals. Further, the residues produced are added into the coagulation tank as a coagulant in the process of chemical coagulation for wastewater treatment, thereby achieving a goal of zero sludge production.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.