自浄作用 じじょうさよう Meanings Noun autopurificatory activity (in the natural world) Kanji 自 self. Read as ジ. 浄 purify. Read as ジョウ. 作 make 用 use. Read as ヨウ. Word lists Yojijukugo (四字熟語) Jinuma: Japanese Dictionary · Word lists