Process

DESCRIPTION OF THE PROCESS

In general the following process steps are involved:
* Mechanical pretreatment with a bar screen, comminutor or pre-clarification.
* Aeration and mixing in the bio-tank with the rotating Bio-Wheel™.
* Clarification, with sludge recycling to the bio-tank and withdrawal of excess sludge.

The heart of the wastewater treatment process is the Bio-Wheel™ which consists of a rotating structure with
patented cell plates arranged in a series of rows. The cell plates are 3/4" apart and provide a roughened surface
as media for fixed film growth, and also provide a source of aeration for the activated sludge. By adjusting the
speed of rotation for varying oxygen requirements, treatment of the wastewater occurs both in the activated
sludge and the fixed film.

During rotation of the Bio-Wheel™, trapped air is gradually released into the mixed liquor as fine bubble
aeration. Some of the air is transferred from one pocket to another inside the cells providing additional
buoyancy reducing energy requirements. Before the cells are rotated to the surface, all air is expended as fine
bubble diffusion. By this method, the time of retention of air-water contact is extended so that oxygen transfer
is optimized.

The rotational speed of the Bio-Wheel™ is adjustable, which regulates the amount of aeration and mixing in
the bio-tank. The deep submergence of the wheel in the mixed liquor increases the efficiency of oxygen
transfer.