Biological treatment of waste water

摘要

There is described a small-sized and low cost waste water biological treating tank especially suitable for domestic installation. The tank 10 contains a porous soft ceramic material 40 which supports the treating microorganisms. Waste or raw water is supplied to the tank from above through a downwardly opening pipe 21, is pushed up by the action of air bubbles generated by a bottom mounted air inlet 30, and then flows over a cylindrical weir 50 into the ceramic material 40 in which the water is purified by microorganisms which digest the nutrient in the water. The surface area of the porous ceramic element 40 is generally about 25 times greater than that of conventional plastics elements. Treated water passes through an outlet 12 and may then be subjected to a centrifugal sludge separation step and an anaerobic biological treatment step (fig. 5).