Organic waste water treating apparatus having treating layer and

Abstract

A primary treating tank (10) comprises a filling layer (14) and a foam glass layer (16) below the filling layer (14). The foam glass layer (16) contains foam glass grains each of which is larger in a grain diameter than a wood chip of the filling layer (14) so that the foam glass layer (16) is superior in water passing ability to the filling layer (14). In this arrangement, a space ratio is larger with a lower layer. This arrangement promotes smooth downward shifting of primary treated water. A secondary treating tank (30) also has a laminating structure including a filling layer (34) and a form glass layer (36). As air is supplied to the foam glass layer (36), the filling layer (34) is kept in a preferable aerobic condition so that preferable aerobic biological treatment is carried out on the treated water supplied from the primary treating tank (10).