Lee Kuan Yew Water Prize 2009

Professor Lettinga has chosen not to patent this invention so that his water treatment technology can be universally available. As a result, his technology has been widely adopted in industrial as well as municipal use. Today, the technology is in use in almost 3,000 reactors, representing about 80% of all anaerobic used water treatment systems in the world.

The Lee Kuan Yew Water Prize is an international award recognising an individual or organisation for outstanding contributions in the field of water. Such works have to solve the world's water problems through the application of revolutionary technologies or the implementation of innovative policies and programmes that benefit mankind.

Professor Lettinga pioneered the widespread use of anaerobic technology, which uses micro-organisms in an oxygen-free environment to purify used water. Although anaerobic technology has been around for over a hundred years, his invention proved that it could be operated as an energy-efficient, cost-effective and self-sustaining process. His anaerobic reactor is able to pre-treat polluted used water from industries such as breweries, beverage, paper and pulp manufacturing, sugar, starch and alcohol distilleries. The used waters produced by these industries contain a large amount of organic contaminants. Some of these contaminants cannot be efficiently removed by conventional aerobic processes, while others are toxic.

With energy-efficiency concerns becoming more pressing, this technology is being increasingly applied, not just to industrial used water, but also to municipal used water in countries like Brazil and India. The anaerobic system is a simpler system compared to aerobic systems as it does away with the use of oxygen, generating energy savings of 30 to 40 percent.