Severn Trent Services offers the TETRA Denite® System for the removal of nitrate-nitrogen (NO3-N) and suspended solids (SS) in a single treatment step. Denite is a fixed-film biological denitrification process that also serves as a deep bed filtration system capable of removing suspended solids to virtually any final effluent requirement. The system integrates well with other plant treatment processes to provide superior total nitrogen (TN) and phosphorous removal. Denite is used as the final treatment step in the total nitrogen removal process to help each facility meet stringent TN discharge limits of 3 mg/l.
The specially sized and shaped granular media used in the Denite process is an excellent support medium for denitrifying bacteria and the deep bed environment is conducive to efficient NO3-N and solids removal. The contact between wastewater and biomass is excellent and hydraulic short-circuiting is negligible even during plant upsets. The media allows for heavy capture of solids of at least 1.0 pound of solids per square foot of filter surface area before backwashing is required.
Key Features and Benefits
- Requires one-tenth of the space used with suspended growth systems
- Single system for denitrification and filtration provides process synergy
- Maintains excellent SS removal
- Eliminates the necessity for clarifiers or additional effluent polishing filters
- High loading capacity
- Easily handles peak flow periods and plant upsets
- Percent of return of wastewater is less than 4% (<2% typical) of the plant’s forward flow
- Features TETRA® SpeedBump® technology to release entrapped nitrogen gas
- Effluent total phosphorous concentrations <0.3 mg/l are consistently achieved
- Can easily meet <2 NTU or < 5 mg/l TSS (<2 mg/l TSS typical)
- Capable of denitrifying to low NO3-N concentrations at low wastewater temperatures