expurgator
/ɛksˈpɜːrdɪtər/Definitions
1. noun
A person or thing that expurgates, especially a book censor.
“The committee acted as an expurgator, removing any offending material from the manuscript.”
2. noun
A device for expurgating, especially a machine for removing impurities from water or air.
“The expurgator in the water treatment plant was crucial in maintaining the town’s clean drinking water.”