Purifying waste water contg. soluble and insoluble pollutants - by adding lime and carbon di:oxide, reacting, then decanting

摘要

Purifying waste water contg. pollutants in soln. and in suspension comprises adding to the water lime and CO2 to form calcium carbonate crystals. The water is left in the presence of the crystals for a sufficient time to absorb the materials in soln. and to flocculate the material in suspension. The sludge formed is then decanted and the purified water sepd.. The process is carried out in a reactor comprising an external reservoir with an outlet for extracting the sludge at the bottom and means for drawing off the purified water at the top. In the intermediate area is provided means for introducing CO2 bubbles near the bottom of the intermediate area; at least one conduit for feeding milk of lime or water and lime into the intermediate area and at least one other conduit feeding in the waste water. The process provides a physico-chemical method which is both very economic and gives excellent results independently of variations in the water treated. It may be used alone or in combination with other known processes.