Concrete Embedded CC Technology Treatment Plants

Principle of WWTP

WWTP utilizes proven technologies of mechanical pre-treatment and aerobic stabilization with pre-denitrification. The system is resistant to load changes, ensuring high cleaning effects with small fluctuations in the quality of treated water. The compact design of the main technological line objects minimizes internal circuits and the built-up area of the WWTP.

The biological reactor of WWTP integrates these three basic parts:

• pre-denitrification part
• nitrification part
• settling part (settling insert)

Denitrification Part

Denitrification is the opposite of nitrification and means the reduction of nitrates and nitrites – oxidized forms of nitrogen present in wastewater – to nitrogen or nitrogen oxides. Denitrification processes occur under anoxic conditions (dissolved oxygen content less than 2 mg/l).

The denitrification mix must be kept in suspension – mixing either pneumatically or with an electric mixer.

If nitrification support is necessary (e.g., in winter months), an aeration system with a separate shutoff is installed in the denitrification.

Activated sludge is hydropneumatically pumped into the denitrification by a recirculation pump from the bottom of the settling insert.

Nitrification Part

Biological nitrogen removal involves the biochemical oxidation of ammoniacal nitrogen to nitrites and nitrates (nitrification processes) and their subsequent removal (denitrification).

This activated sludge can be separated from clean water by sedimentation.

Through an opening in the dividing wall between the nitrification and denitrification spaces, the denitrification mix flows into the nitrification zone. Nitrification is continuously aerated pneumatically by fine-bubble aeration.

An aeration system with a separate shutoff is installed at the bottom of the nitrification, and the activation mix is kept in suspension by aeration. The dissolved oxygen concentration in nitrification should range between 2.5 to 4.0 mg O2/l.

A portion of the cross-circulating mix of activated sludge and treated water flows into the settling area, where the activated sludge is separated and thickened.

Settling Area (Settling Insert)

The settling area is formed by an insert, which can have various shapes – conical or triangular prism shape. A pipe through which return sludge is hydropneumatically pumped back into denitrification is placed at the bottom of the settling area.

The treated wastewater is drained by a collectible, height-adjustable outflow channel, and the sludge is sucked from the bottom of the settling insert and hydropneumatically transported as return sludge into the denitrification tank.

Description of WWTP

The biological reactor consists of a reinforced concrete tank, into which a technological insert is placed. The volume of the tank is divided into individual functional spaces by the settling insert (stainless steel construction). Wastewater is pumped into the denitrification zone of the biological reactor. A mixer is installed in this zone. Water flows from the denitrification area into the oxic zone – nitrification. This zone of the bioreactor is equipped with a fine-bubble aeration system – tubular aeration elements (plastic). Water flows from the nitrification space into the settling insert, where the treated water is separated from the activated sludge. Clean water then flows out from the surface via an overflow channel (stainless steel) into the outflow pipe.

Internal (recirculation) flow of the activation mix is ensured by a mammoth pump. These pumps suck the activation mix from the area of the settling insert and return it back to the beginning of the cleaning process – into the denitrification zone.

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