Polyether defoamers take polyalkylene glycol as the main active component. They are good at foam prevention rather than only breaking formed foam, with excellent dispersibility in water. They are biodegradable to a certain extent and have less adverse impact on activated sludge microorganisms.

**Applications**: Preferred for continuous dosing in biochemical treatment systems, anaerobic reactors, UASB and sludge digestion units. Widely used in food processing, printing and dyeing wastewater where biological activity must be protected.