Microorganism immobilization carrier, DHS reactor, biological nitrification denitrification apparatus and method of use thereof

摘要

PROBLEM TO BE SOLVED: To provide a microorganism-immobilized carrier which allows a high level of filling and free setting of a filling ratio, a DHS reactor using the microorganism-immobilized carrier, a biological nitrification and denitrification apparatus which uses the DHS reactor and is inexpensive and excellent in nitrogen-removing performance, and a method for using the biological nitrification and denitrification apparatus which can be applied to a wide range of nitrogen-containing wastewater.SOLUTION: In the microorganism-immobilized carrier 80 for immobilizing microorganisms, which is filled and used in a wastewater treatment reactor using a biological treatment method, the wastewater treatment reactor is the DHS reactor, a trickling filter type reactor or an aerobic filter type reactor. The carrier is a plate-like body formed of zeolite. The outer edge part of the plate-like body has the same size as the cross section of the wastewater treatment reactor. The carrier is fitted into the wastewater treatment reactor without any clearance, has enough strength not to be deformed even when a plurality of the carriers are stacked, and has through-holes 82a, 82b, 82c, 82d and 82e bored therethrough so that the void ratio can be adjusted.