When I was at a very young age, I had already been told that rubbish is just a kind of misplaced resources. There is such a conception in my mind many years. Everything has its own value as long as we change it and use it in a reasonable way. In this paper, I focus on the water resource. Wastewater means the water that lose the function comparing with pure water before. However, it just because of the outside environment changes or mix of new substances. So it is possible to make the wastewater useful again.