摘要 |
The invention relates to a process for purifying chromium-containing wastewaters, which comprises a) heating the wastewaters to the temperature range from 50 to 100 DEG C, b) adjusting the pH of the wastewaters to the range from 9 to 14, c) treating the alkaline wastewaters with a reducing agent in the pH range from 9 to 14, and d) enriching the resultant chromium-containing precipitate by ultrafiltration, isolating the enriched precipitate from the filtrate and, if desired, further processing the isolated chromium compound. |