noun
flocculant; coagulant
Technical term in chemistry and water treatment for a substance that causes fine particles to clump together.
浄水場では凝集剤を使って水中の微粒子を沈殿させる。
At water purification plants, flocculants are used to precipitate fine particles in the water.
Compound of 凝集 (ぎょうしゅう, 'coagulation, flocculation') and 剤 (ざい, 'agent, chemical').