Skip to main content

CHEMICAL ENHANCED PRIMARY TREATMENT – PILOT INVESTIGATION AND CASE STUDIES IN BRAZIL

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

CEPT is a wastewater treatment technology based on suspended solids removal by physical-chemical processes of coagulation, flocculation and sedimentation. Physical-chemical treatment is indeed an old and a well-known technology. It was applied in the U.S. until the 1930s, when it fell into disfavor, with the advent of the activated sludge process, at the time more efficient and less costly. The recent offer of less costly chemicals, and of new polymers, brought back the physical-chemical treatment, now as a primary step ahead of conventional secondary biological treatment, known as Chemical Enhanced Primary Treatment. In the CEPT coagulation step, low dose iron salts are applied, typically ferric chloride, ranging from 25 to 50 mg/L. Flocculation is achieved with supplementary addition of an anionic polymer.

The CEPT process increases organic matter (BOD) and suspended solids (TSS) removal up to 50% and 80%, great figures when compared to what can be achieved in conventional primary treatment, 30% and 50% efficiencies. Taking into account these figures, 3 new plants have been built in Brazil under this process (final design flow 3 m3/s), with excellent performance.

In the current year, an investigation on the process efficiency under different chemicals and mixing conditions has been pursued, at the Treatment Research Centre (CETE) of the Universidade Federal do Rio de Janeiro, in Rio de Janeiro, Brazil. The project goal is to run the process under diverse conditions, so that its feasibility can be enhanced, technically and economically, for the Brazilian scenario.

The experimental pilot plant works with 3 different coagulants, including an organic tannin compound, adding these chemicals to the sewage flow at an aerated grit chamber, where air mixing can be controlled. Two identical clarifiers, side by side, one receiving raw gritted sewage, and the other receiving the chemical enhanced gritted one, allow comparisons at different flows and overflows. Control of air and sewage flows, coagulant dosages, and proper indicators are achieved.

Sludge generation is increased in the CEPT concept, and naturally this will increase costs in sludge conditioning, stabilization and drying.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Data/Media
No Metrics

Document Type: Research Article

Publication date: 2005-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more