Clarification of water by downflow flocculation, lamellar settling, and subsequent micro-bubble floatation

摘要

In tank 22 flocculants are stirred into dirty water to be clarified and from there the dirty water flows down through the baffles 18 of static flocculator tank and through the lamellar settler 19 positioned directly below the static flocculator. The lamellar settler removes relatively heavy particles of the suspended matter from the water, the removed particles being collected from the sump 20, whilst the light particles and some relatively heavy particles having settling rates less than or equal to the settling rates of floatable particles of the suspended matter are retained in the water. The contaminated water that has passed through the flocculator and settler is then passed to a floatation unit 12 that includes a pressurization-expansion system 13 generating micro-bubbles in the floatation unit for floatation of the remaining particles in the water.