| 摘要 |
<p>1. A process for the removal of dyes, pigments and/or optical brighteners, for example of the textile, paper, leather, foodstuffs and plastics industry, from sewage, primary flocculants in the form of iron and aluminium compounds and secondary flocculant adjuvants in the form of cyanamide, melamine or pyridinium derivatives or of other cation-active organo-compounds being added and the resulting coagulate being separated from the sewage, characterised in that the removal of the dyes, pigments and/or brighteners from the sewage is performed as a flocculation filtration, the primary flocculants and the secondary flocculant adjuvants being so added to the raw water before a filter bed (1) of granular material, the bed serving for filtration, that flocculation or flock formation occurs at least to some extent in the filter composition (5, 6) by arranging for an average dwell time of the sewage to be treated of less than 45 minutes between the final dispensing station (11 or 12) for the flocculants and flocculant adjuvants and the granular filter composition (5, 6).</p> |
