中水是什麼意思

中水（Japanese: 中水, Chinese: 中水, pinyin: zhōngshuǐ, Japanese: nakagawa, Korean: 중수, romaja: jungsu) is a term used in East Asia to refer to reclaimed water that has been treated and is suitable for non-potable uses, such as irrigation, flushing toilets, and industrial processes. The term literally means "middle water" in Japanese and Chinese, indicating that it is a grade of water quality that is not as pure as drinking water (上水, shangshuǐ, or "upper water") but is cleaner than wastewater (下水, xiàshuǐ, or "lower water").

In many parts of the world, including East Asia, the use of reclaimed water for non-potable purposes is an important strategy for conserving freshwater resources and managing wastewater in an environmentally sustainable way. By treating wastewater to a high standard and reusing it for non-potable purposes, cities and industries can reduce their demand on freshwater supplies and the environmental impact of wastewater treatment and disposal.