noun
self-purification; autopurificatory activity
Refers to the natural ability of an environment (e.g., a river, soil, or the atmosphere) to cleanse itself of pollutants or impurities. Often used in ecological or environmental contexts.
川の自浄作用が働いて、水質が改善された。
The river's self-purification ability kicked in, and the water quality improved.
環境保護の観点から、自浄作用の限界を理解することが重要だ。
From an environmental protection perspective, it is important to understand the limits of self-purification.