TIn dissolved air flotation process a portion of the effluent from the flotation tank is recycled through a saturator where air is injected at high pressure. The pressurized recycle flow is introduced to the inlet at the bottom of the tank where it is mixed with the incoming flow.
This sudden drop in the pressure produces super saturation of the water with air and a cloud of air bubbles, which attach themselves to the particles in the suspension, are released. These air bubbles along with the particles float at the top of the tank as scum and can be removed. The cycle is repeated to produce an effective removal of suspended particles.
Dissolved air flotation has certain advantages over the sedimentation tank processes. They are effective in water treatment when chemical coagulation is used to remove dissolved substance such as color, iron and manganese. They produce lower turbidity output.
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