ABSTRACT
Water is an essential element for the existence of life. Many physiological reactions have to occur in water solution. Where water is present, life is possible. Where it is absent, life can not sustain. Water is one of the most abundant substances on earth. However, the quantity of water that is available for human beings to use without laborious treatment is very limited; for example, only 1% of the world’s total is freshwater [1]. Therefore, it is important to make the best utilization of water.
