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Hydro-Action Standard 245

AN Series Nitrogen Reduction

The Hydro-Action® AN Series individual wastewater treatment plant is a self-contained, extended aeration, aerobic treatment facility utilizing the combination of the activated sludge process and wastewater recirculation for denitrification.

The plant consists of an engineered pre-treatment septic tank and a cylindrically shaped aeration tank with an offset service access, a unique cone shaped clarification compartment and an outlet tee-assembly. Three fine-bubble air diffuser assemblies with hard pipe diffusers and Hydro-Action® efficient air pump are combined to provide effective, efficient, and economical aeration.

Domestic wastewater enters the aeration compartment and is mixed thoroughly with the already present mixed liquor suspended solids (MLSS) activated sludge. The injection of air through the porous air diffusers placed near the bottom of the aeration chamber is responsible for this complete mixing. The fine-bubble diffusers and the vortex area between diffuser assemblies produce a high magnitude of air diffusion and therein provide ample mixing and a more than generous quantity of dissolved oxygen to maintain the aerobic environment even under extreme conditions.

Hydraulic displacement causes the mixed liquor to enter the clarification compartment and move upward toward the outlet tee-assembly.  Due to the calm conditions in the clarifier, suspended solids settle to the bottom where they are remixed with the Mixed Liquor Suspended Solids (MLSS) for additional biological treatment. The remaining clarified effluent leaves the plant via the outlet tee assembly and discharge line.

The AN Series ATUs are operated by the OPS®. The OPS® integrates the electrical controls, visible and audible alarms and air pump in a protective polyethylene enclosure. The OPS® can be either platform mounted on the plant or remotely located. These features plus the offset access, airline piping, and diffuser assemblies make the plant extremely reliable and easy to service. The visible and audible alarm may be added to remotely locate to an area of your choice.

The Nitrogen removal portion of the process begins with a protected recirculation process. The recirculation pump takes portions of the mixed liquor and returns it to the pretreatment tank. Anoxic conditions cause the nutrient reduction process. Agitation is initiated with the mixing pump inside the pretreat tank. Effluent is allowed to pass into the aeration compartment of the ATU by gravity.

The technology used in the Hydro-Action® plant allows it to produce excellent effluent quality, which thereby meets all ANSI\NSF International Standard 40 & 245 class I and the Environmental Protection Agency’s requirements of a secondary treatment process and Nitrogen reduction. NSF requires that a Class I plant shall be shown to meet EPA secondary treatment guidelines for CBOD5, TSS, and ph. The Hydro-Action® AN Series ATUs satisfy all these requirements. It also surpasses state-determined field verified testing of Total Nitrogen Effluent levels in Maryland and New York.