Method for chromium removal from post-tanning wastewater
US12264094B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 2022 |
| Grant date | Apr 1, 2025 |
| Priority date | — |
| Expiry date | Jun 30, 2043 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2103/24
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method for chromium removal from post-tanning wastewater includes the following steps: (a) mixing pretreated post-tanning wastewater with an induction reagent to allow an induction reaction; and (b) adjusting a pH of a mixture obtained after the induction reaction to higher than 7.0 for precipitation; where the induction reagent includes a soluble metal salt. In the treatment method of the present disclosure, pretreated post-tanning wastewater is mixed with an induction reagent, a small amount of neutral chromium complexes remaining in the wastewater are converted into cationic chromium complexes under the action of the induction reagent (that is, a charge property of the chromium complex is changed), and then a pH is adjusted for precipitation to remove chromium, which greatly improves the removal efficiency of chromium in wastewater.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.