Submerged Activated Fixed Film Reactor
SAFF is “Submerged Activated Fixed Film Reactor” is a type of aerobic attached growth treatment process. It is principally designed to enhance the efficiency of conventional activated sludge process. The conventional process tanks occupy larger land area, involve constant monitoring of parameters like MLSS & SVI, require continuous power supply and are susceptible to shock loads. SAFF reactor, whereas , needs , less power , lower volume, no recycling of sludge , less footprint area, besides allowing higher loading to make it an acceptable product. With lower sludge generation plug flow design for positive treatment, SAFF reactors help the ETP users do away with a host of monitoring and running costs, making operations of ETPs easier. Besides this, parallel plate separators and tube settlers are products that are today replacing huge solid/sludge removal equipment.
The use of structured plastic media with the Activated sludge process helped to reduce the volume of the tanks with increased performance. The SAFF systems can easily fit in to underground basins because of small foot print area hence the system is most useful for Sewage Treatment Plants in crowded cities where space is a constraint.
The SAFF system can be designed with single stage or two-stage system depending on inlet BOD and COD and other parameters. The system involves attached growth and submerged growth treatment process. Media such as the COOLFill structures Media occupies around 50 to 70% tank volume depending on the type of effluent and rest of the portion is utilized for suspended growth as in the conventional aeration tank.