The pH, the turbidity, the color, suspended solids, and COD.
pH 值、浑浊度、颜色、悬浮物和 COD（化学需氧量）。
英语百科
Suspended solids
Suspended solids refers to small solid particles which remain in suspension in water as a colloid or due to the motion of the water. It is used as one indicator of water quality.
It is sometimes abbreviated SS, but is not to be confused with settleable solids, also abbreviated SS, which contribute to the blocking of sewer pipes.