diffuser

https://doi.org/10.1351/goldbook.D01715
A porous plate or tube, commonly made of carborundum, alundum or silica sand, through which air is forced and divided into minute bubbles for @D01716@ in liquids.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2184 [Terms] [Paper]