One of the priority issues of communities is to supply healthy, reliable and continuous water; and to discharge the contaminated water collected in a healthy and safe manner after treatment. Water has an important place in our individual life, and also it is an important input for many industrial plants in different sectors. The value of water is increasing due to enlarging of population, the progress of technology and the development in industry day by day.

Water is never found pure in nature. At the same time, since water is a very powerful solvent, it takes in the salts which encounters on its route by dissolving them. Thus, the presence of ions such as Ca +2, Mg +2 in water gives a property called hardness. These ions and dissolved gases  in the water cause scale and corrosion in the heating and cooling systems. For this reason, water to be used, especially in heat transfer systems, must be purified and treated before being added to the system.