METHOD FOR REMOVING NITROGEN OF SEWAGE

摘要

PROBLEM TO BE SOLVED: To maintain a stable and high nitrogen removing rate over a long period of time while achieving the miniaturization and reduction of production cost of a biological filtering treatment apparatus in the nitrogen removing treatment of sewage using biological filtering treatment. SOLUTION: In a nitrogen removing method of sewage using a biological filtering treatment tank A0, a treatment tank main body 1 is packed with a large number of filter blocks 6 formed by mutually bonding a large number of volcanic pumice particles with a diameter of 3-30 mm by a binder to form them into amorphous lumps with a max. length dimension of 20-250 mm and sewage is allowed to flow through the treatment tank main body 1 while air is ejected from the air diffusing device 4 provided to the bottom portion of the treatment tank main body 1.