Clean, safe drinking water is scarce. The World Health Organisation (WHO) has set international guidelines for drinking water. Almost all countries have applied water quality regulations, often inspired by WHO guidelines. According to estimation of the United Nations, over 1.1 billion people are currently devoid of continuous access to safe and clean drinking water. It is predicted that a significant fraction of the global population (over 3.5 billion people) will be living in areas with severe water shortages by the year 2025. More than half of the world’s hospital beds are occupied by patients suffering from waterborne diseases. Many of these diseases can be prevented by providing safe drinking water. In this context the role of desalination and water purification technologies are vital.