Vol. 8, Issue 10 (2019)

Water is a limited resource and demand for it is increasing at an alarming rate. Safe, clean and adequate drinking water is vital for the existence of all living organism. It is a foundation of livelihoods and is the key to sustainable development. The quality of drinking water has become the most important natural determinant of well-being. Further, access to clean drinking water is the foundation for control and prevention of waterborne diseases. Declining water quality has developed into a global threat as the human population grows, agricultural and industrial activities expand and constant change in the hydrological cycle because of climate change.

Being a universal solvent, water is a major source of infection. According to the World Health Organization (WHO) 80% of diseases are water borne. Drinking water in various countries does not meet WHO standards. 3.1% of deaths occur due to the unhygienic and poor quality of water. It is really important to make sure that any product that we use or consume is clean and hygiene, this applies for water as well. If it is harmful, the contents have to be eliminated or neutralized to make them harmless. The water comes from various sources. As the sources changes, quality of this water also changes because it is a universal solvent and it dissolves more of substances than any other liquid. So, in order to purify the water which is toxified, various methods have been adopted since ages.