Tricel NOVO EN6-50, User Manual

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1.The wastewater purification process:
4.1 Stage 1: Primary settlement chamber:
The wastewater is introduced into the primary chamber. The large volume of this chamber reduces velocity
of the wastewater. This along with the long flow path allow the wastewater maximum time in the first
chamber resulting in a higher settlement rate. Settlement occurs when the heavier solids, drop out of the
wastewater and settle to the bottom of the tank to create sludge and when lighter solids, like fats or oils,
float to the top of the water to create a scum. Up to 70% of the solids are removed in Primary settlement
zone. Anaerobic breakdown begins to occur and improve the water quality. A baffling system holds
the sludge and scum in the primary settlement zone and allow wastewaters to move into the aeration zone.
The large sludge storage volume increases the de-sludging intervals.
4.2 Stage 2: Aeration (treatment) chamber:
Stage 2 takes place in the aeration chamber where submerged aeration combines the principles of the bio
film and activated sludge processes. Masses of naturally occurring bacteria inhabit specially designed
plastic filter media. The filter media, has large surface area, and is supported within the aeration zone. As
the liquid flows slowly through the filter media the bacteria feed on the waste removing them from the
liquid. These bacteria are sustained with air, which is continuously supplied from a purpose built low
pressure, high volume air compressor in the top section of the unit. The air is delivered through a diffused
aeration system, which break the air into bubbles as they are dispersed through the aeration zone. The
continuous circulation of the wastewater within the aeration zone means that the wastewater is passed
through the filter media over and over, thus ensuring very high treatment efficiency. The purified liquid is
then passed into the final settlement zone.
4.3 Stage 3: Final settlement chamber:
As the liquid flows from the aeration zone into the final settlement zone small quantities of bacteria may be
carried with the liquid. Before discharge from the plant, these solids must be separated from the liquid. With
the velocity of the liquid slowed down and the flow path maximised the bacteria settles to the bottom of
the tank, like sludge, through the up flow nature of the zone. A sludge return system pumps this sludge
back to the primary settlement zone. The remaining treated liquid now meets the required standard to be
safely passed out of the Tricel Novo plant.