noun
sewage treatment; wastewater treatment
Refers to the process of treating sewage or wastewater, typically in a municipal or industrial context.
この町の下水処理施設は最新の技術を使っている。
The sewage treatment plant in this town uses the latest technology.
浄水 refers to water purification in general, often for drinking water, while 下水処理 specifically means sewage or wastewater treatment.
Compound of 下水 (sewage) and 処理 (treatment, processing).