| has gloss | (noun) layer of sand or gravel used to expose sewage effluent to air and the action of microorganisms
bacteria bed |
| has gloss | eng: A bacteria bed is a layer of sand which is used to clean air or water from bacteria and other microorganisms. It is actually a type of filter. |
| has gloss | eng: Sand filters are used for water purification. There are three main types; # rapid (gravity) sand filters # upflow sand filters # slow sand filters |
| lexicalization | eng: bacteria bed |
| lexicalization | eng: sand filter |
| subclass of | (noun) device that removes something from whatever passes through it
filter |
