净化污水的英文：
purify sewage water

To cleanse or purify or become cleansed or purified.
（使）清洁，（使）净化

purify or refine,esp by repeated distillation
净化或精炼;（尤指）分馏,精馏

To increase the concentration of, separate, or purify by or as if by distillation.
精炼用蒸馏法或好象用蒸馏法增加浓度、分离或净化

The sewage channel chokes.
这条污水道塞住了。

defile a river with sewage.
用污水弄脏河流

The air is thick with the stench of sewage.
这里的空气里弥漫着脏水的恶臭味。

In smooth water
进入顺境

Is the water on or off?
自来水龙头开着还是关着？

Water Skiing is a surface water sport.
滑水是一项水面运动。