Updated: July 2002

1. Purpose

Acticontact is a wastewater treatment system based on the formation of biological films. While wastewater bearing BOD is passed through a packed-bed, BOD substances therein are fed on and decomposed by microorganisms grown on the packed-bed, thereby accomplishing an effective treatment of the wastewater. Acticontact can take exceeding high BOD loadings, and it can be used as "roughing filter"to reduce the organic loading on downstream processes.

2. Performance

Allowable BOD loading: 3.0-15 kg BOD/(m³d)
Installation space requirements: small
Running cost: lower than activated sludge process
MLSS retained (mg/l): 10,000-15,000
Sludge acclimation: easy
Maintenance: easy
Sludge volume: minimal
Shutting down: amenable to stoppage of an extended period of time

3. Characteristics

1) Higher BOD Loadings: The packing medium of Acticontact has surface areas as large as 200 to 500 m²/m³. Microorganisms are retained not only on these medium surface areas but also in medium interstices, thus achieving an MLSS concentration of 10,000 to 15,000 mg/l.
2) Better Adaptability to Fluctuations in Wastewater Quality: Acticontact can well cope with any substantial variations in BOD loading and pH, and any other changes in the operating conditions.
3) Smaller Volume of Sludge Generated: A longer food chain formed by many species of microorganisms results in smaller volume of sludge generated in the reactor tank.

4. Flow Diagram and Number of Plants Installed

About 160 sets of Acticontact have been installed for a total wastewater flow of about 850,000 m³/d.