Category	Item	Air bubble type	Mechanical type	KUH KAI
Oxygen transfer rate	No clogging	×	○	◎
	Free intermittent running and denitrification	×	○	◎
	No sludge flocculation on the tank bottom	×	×	◎
	Impact on microorganisms (floc, etc.)	◎	×	◎
Maintenance	Power saving (small pressure loss)	×	×	◎
	Facility cost (easy installation and piping)	○	×	◎
	Operation management (Parts replacement, etc.)	×	×	◎
	Repair and durability	×	×	◎