Two-stage wastewater treatment
US4810386A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 1988 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Jan 4, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/10
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A two-stage process for purifying wastewater containing organic and adsorbable pollutants includes the steps of first aerating the wastewater in the presence of a powdered adsorbent, such as activated carbon, and biologically active solids in the aeration zone of a primary treatment zone which also includes a quiescent zone. The thus-treated water passes from the aeration zone to the quiescent zone where it is retained a sufficient time for a substantial portion of the suspended solids to settle by gravity. The partially-treated wastewater overflowing from the quiescent zone is introduced into one or more contact zones wherein it is agitated, preferably by aeration, in the presence of a powdered adsorbent, agitation is terminated and the solids are allowed to settle by gravity and, after completion of settling, clarified, substantially solids-free water is withdrawn from each contact zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.