De Nora TETRA® Biological Filtration

De Nora’s flagship biofilter with over 300 installations is the DE NORA TETRA Denite System, which biologically reduces soluble nitrates to nitrogen gas in an anoxic environment.

Why De Nora TETRA® Biological Filtration?
DE NORA TETRA biofilters can be designed in a variety of configurations to achieve optimal treatment for biological oxidation of organic compounds, nitrification, and denitrification.
Remove soluble and particulate contaminants in a single step, simplifying your plant operations while increasing removal performance.
In addition to anaerobic systems, DE NORA TETRA ColOXTM, SAF, and NSAFTM are aerobic biofilters used for BOD/COD oxidation and nitrification.
For even greater removal or treatment of challenging contaminants, DE NORA TETRA ABF biologically active filters combine ozone and biological filtration to treat Contaminants of Emerging Concern (CECs). Systems utilize the rugged Snap T block underdrain which will not clog or lift in biological applications. In addition, they provide excellent distribution of backwash air and water keeps filter media clean. With no small openings, nozzles, screens or moving parts to clog or wear, they will provide a long service life, maximizing your investment. It can accommodate a wide range of media types and sizes for maximum process flexibility and performance.

Existing De Nora media filters can be easily upgraded to biologically active mode as well.

De Nora TETRA® Biological Filtration: Denite® System Components and Specifications 

Filter Bottom: Nozzleless design; stainless steel air headers and pipe laterals; plastic jacketed 5000 psi concrete SNAP T® Block underdrains
Filter Media: Monomedia granular sand with 2-3 mm effective size at depths of 4-to-8 feet
Support Layers: Gravel in five layers totaling 18 inches deep in a reverse graded fashion
Filter Controls: Either constant rate filtration with constant head using modulated effluent valves controlled by level element, or constant rate with variable head using open/close effluent valves
Backwash Air: Distributed across the entire area of the filter bottom, supplied by a positive displacement blower at a rate of 3-5 icfm/ft²
Backwash Water: Supplied at a rate of 5-6 gpm/ft² with a low head centrifugal pump. The head loss across the filter bottom is 4.0 inches water column.
Filter Valves: Pneumatic or electric control valves with double acting cylinders. It can include solation valves.
Chemical Feed Systems: Includes a methanol storage and feed system with TetraPace™ automatic dosing control. 
Instrumentation: PLC with human machine interface and multiple screens included. Also includes outputs for a centralized computer control and/or SCADA system. It also includes flow meters, analyzers, level switches, local panels and system alarms.
Filter Operation: Automatic with manual overrides. Backwashing and bumping are time based.
Head Requirement: Typically 6-8 feet of water but can be more or less depending on the specific application
System Integration: Works well with other treatment plant processes such as overall nitrogen removal, phosphorous removal and virus removal

Nulantic Water is an exclusive representative of De Nora TETRA® Media Filtration and is proud to serve customers and projects based in Atlantic Canada.

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