Process and apparatus for purifying water

A grey water bubble separator which includes:

• a receptacle having a floor, an opposed ceiling and a side wall to define a separation chamber, the receptacle defining at least one inlet in the floor for aerated grey water containing bubbles, a first outlet for removal of water from the separation chamber after separation of the bubbles from the water;
• and
• a throat-defining member defining a second outlet for removal of separated bubbles from the separation chamber and having at least a portion projecting through the ceiling into the separation chamber,
• wherein the receptacle and the throat-defining member form a bubble reflector, the bubble reflector comprising the ceiling of the receptacle and that portion of the throat-defining member projecting into the separation chamber,
• wherein the second outlet is arranged closer than the ceiling to the at least one inlet, the bubble reflector defining a shape which in cross-section is configured to promote recirculating flow of a foam column constituted by the separated bubbles to reduce a column height required to produce a dry foam.