- Aerobic
- Anoxic
- Anaerobic
The fixed film system overcomes solids seperation problems often seen in suspended growth system’s secondary clarifiers. In effect, the fixed film allows for a higher MLSS (up to 3,000 mg/L higher) than a comparable suspended growth system. This directly translates to:
- Increased treatment capacity with a given foot-print
- Ability to meet permits by retro-fitting an existing plant
- Less susceptiblity to shock loadings
- Can allow for better nutrient removal with respect to both nitrogen & phosphorus
- Initial expense for installing the system
- Maintenance of aeration system more difficult with media
- In mobilized media systems the screens must be maintained to prevent media loss
- All are susceptible to fouling – especially from oil & grease that encapsulates the biofilm