Water in nature constantly flows and transforms under the action of sunlight and gravity, and forms various forms of water sources through cycles such as precipitation, infiltration and evaporation. In the natural cycle, water is mixed with various impurities to varying degrees, which changes the water quality. The source of its impurities is basically divided into two categories: one is the natural process. For example, the initial precipitation (including rain, snow, etc.) dissolves various harmful substances before reaching the ground; the water dissolves some soluble components in the formation minerals; the silt and humus brought in by the water flow to the surface and the river bed; Various types of microorganisms in water, reproduction of native animals and plants and their dead remains, etc. The other is that the development of human society leads to water pollution.
Such as rain, river, well,running water. Some countries are water-deficient area for instance Kuwait, Congo, Uganda, Kenya,Indonesia,Brazil etc.
We can design a small machine to handle this kind water and let the people there recycle the water and improve their life quality.