我们常说,水是宝贵的。这里的水一般指的是淡水资源,他对于人类的生产生活来说,须臾不可缺失。然而,淡水资源不足,在今天已成为人们日益关切的问题。有人预言,19世纪争煤,20世纪争油,21世纪可能争水。有人也许会问,既然水资源稀缺,海水也是水,能不能从海水中提取淡水呢?从表面来看海水淡化似乎很简单,只要将盐与淡水分开即可。但事实上,海水淡化是人类数百年来孜孜以求的 We often say that water is precious. The water here generally refers to the freshwater resources, and he is indispensable to the production and living of mankind. However, the lack of freshwater resources has today become a matter of increasing concern. Some people predict that in the nineteenth century, coal will flourish in the 20th century and may win water in the 21st century. One might ask, since water is scarce and seawater is also water, can freshwater be extracted from seawater? Desalination on the surface seems simple, as long as salt and freshwater are separated. In fact, desalination has been sought after by mankind for centuries