# filtration

/fɪɫˈtɹeɪʃən/ (US) · /fɪltɹˈeɪʃən/ (UK) · CEFR B2 · Noun

Source: https://englishreference.com/word/filtration
Updated: 2026-05-06

## Definition

the process of passing a liquid or gas through a special material to remove dirt or solid pieces. You use this to make water clean or to separate different materials.

For teachers: the mechanical or physical operation used for the separation of solids from fluids by interposing a medium through which only the fluid can pass. Often used in industrial, chemical, or biological contexts.

## Examples

- The water needs filtration before it is safe to drink.
- The city's new filtration plant removes microscopic pollutants from the reservoir to ensure high-quality tap water.
- Advanced membrane filtration techniques allow for the desalination of seawater, providing a critical source of potable water in arid coastal regions where natural springs are scarce.

## Usage notes

- Uncountable when referring to the general process; countable when referring to a specific method or instance of the process.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.