The A2F process is a combined enhanced aerobic filter and aerated filter.
A reduction in the generation of sludge and aeration volume can be achieved. Hitachi has extensive experience and know-how with this system (46 sites in Japan as of 2016).
Approximately 2/3 of organic matter in the sewage water is gasified by the anaerobic reaction, resulting in a small quantity of sludge and low power usage and operating expenditure.
This process is suitable for small-scale municipal sewage water treatment (less than 10,000m3/d).
Principles
Flow diagram and Structure
Features
Low sludge production
Energy saving (low aeration volume)
Easy operation (no need for sludge control)
Stable performance
(In-house comparison)
Application
Increase of small-scale WWTP in developing countries.(Urban→Regional)
Necessity for low environmental impact for WWTP
Insufficiency of skilled operators for WWTP
Aerobic biological process has high OPEX
Conventional anaerobic process has low OPEX, but controllability is inferior.