Prof Gatze Lettinga on Social Security For All Through Clean Water Treatment

The Lee Kuan Yew Water Prize 2009 winner shares with Gaia Discovery his thoughts on socio-economics, technology, and the value of sludge.

by Mallika Naguran


Prof Lettinga wants sustained environmental protection. Photo: Mallika

Singapore 25 June 2009. It was indeed music to my ears to hear a top scientist who is also this year’s recipient of the Lee Kuan Yew Water Prize espouse the idea of going back to the basics when it comes to sustainable water management. The object behind sustainability, according to the inventor of an improved anaerobic technology for treating used water, is closing both water and waste loops to ensure environmental protection. By doing that, people everywhere, young and old, and especially children can live in secure and clean environments.

To achieve a physically clean habitat is to "try to obey nature", says Prof Lettinga during the Singapore Water Lecture at the Water Week on 23 June. This involves keeping things as simple as possible, like separating the solids from the liquids in sewage collection, and "minimising the water used to collect the solids”. So, no flushing.

Prof Lettinga talked about Natural Biological Mineralization Routes (NBMR) involving concepts of Decentralized Sanitation and Resource Recovery and Reuse (DESAR) where transport of waste is kept optimal and pollutants valorized. The adoption of anaerobic waste processes replace landfills, which in his opinion, are "outdated". The types of anaerobic digestion he refers to are dry digesters (e.g. Danco, Biocell) and slurry digesters (e.g. septic tanks).

But the major difficulty in getting these concepts implemented, says the Netherlands-born scientist, is more of a sociological nature rather than technological due to the short-term commercial interests of established structures. This “conflicts with the moral and practical imperatives to ensure sustainability and drastically improve the life conditions of the world's poor”, he argues.

Prof Lettinga began research in 1970 while working with the Wageningan Agricultural University after having read a journal written by Perry McCarthy on the difficulties of containing organic pollutants in treating used water in the potato starch industry. In his mind, an anaerobic method that began in the States in 1910 that soon went out of fashion by 1935 could be improved to treat the high sugar content derived in the waste water of beet and potato starch companies. "It was a complete black box and nobody understood it," said Prof Lettinga, referring to the complex processes involved in that technology. Aerobic technology, was simpler and widely adopted, but with greater inefficiencies.

The opportunity to develop his idea into a new technology came when a potato starch manufacture company decided to give him a go. With the industrial trial, it then took another five to six years to develop the technology full scale. It was found to be highly effective for treating low and medium-strength used water. Compared to aerobic process, the anaerobic method saves energy from 30 to 40 percent. Methane generated is then collected for fuel.

Prof Gatze Lettinga’s revolutionary concept enables industrial used water to be purified cost-effectively that also produces renewable energy, fertilizers and soil conditioners. Prof Lettinga chose not to patent this invention so that the water treatment technology could be made universally available. As a result, his technology has been adopted in industries worldwide as well as municipalities. The technology is already in use in nearly 3,000 reactors, representing about 80 percent of all anaerobic used water treatment systems in the world.

 President Nathan presents the award to Prof Lettinga at the Istana. Dr Tony Tan (right) spoke of 39 nominations received from 19 countries.

President Nathan presents the award to Prof Lettinga at the Istana. Dr Tony Tan (right) spoke of 39 nominations received from 19 countries.

On receiving the Lee Kuan Yew Water Prize 2009 award from the President of Singapore S R Nathan, Prof Lettinga said that his technology fulfilled his dream for “a secure and clean environment for all”.

The professor, a self-confessed idealist, is convinced that with today’s technological achievements, the threat of poverty can be eliminated, giving rise to greater social security, “barring incompetence” he adds. He also hopes that with the award, a clear signal will go out to anaerobic skeptics across the world. Anaerobic is not considered too favourable due to odour control that needs to be administered, among other complexities.

I asked him later over a tea session about how he felt now about his decision not to patent his Upflow Anaerobic Sludge Blanket reactor."I had doubts initially about not patenting because I thought I may lose control," shares the Prof. But he soon discovered that companies during their adoption of the technology needed to retain his services, and that of his students as well, as they lacked the know how during the development. "They did design some secondary facility on their own, for example, the gas collector, but it (not patenting) worked because of the transfer of knowledge that was made possible."

The accessibility to the technology also meant that companies and industries could get creative on the implementation of the solution. However, it was not always Utopia, and altruism may not have a symmetrical effect. Prof Lettinga shared that a certain company had intended to patent his technology under its own name for commercial use. He quickly reacted by announcing the solution publicly, and the company's patent plan was thwarted.


Singapore's first prime minister Lee Kuan Yew congratulates the new winner.

To this day, Prof Lettinga has no regrets. Due to his generosity and foresight, Prof Lettinga's technnology has been extended to treating used water in countries like Brazil, Egypt and India. Even Singapore has adopted some elements of the technology to reduce the energy costs of treating used water, which is then purified into NEWater.

Prof Lettinga was a professor of Environmental Technology from 1988 until his retirement from Wageningan Agricultural University in 2001. He set up Lettinga Associates Foundation and is an active Board member in the not-for-profit knowledge centre on sustainable environmental protection technologies. Many young scientists can now put their wild schemes into fruition through sponsorship of scholarship programmes. The Foundation will soon receive an injection of SGD300,000, the Lee Kuan Yew Water Prize money from the Singapore Millennium Foundation

So keen is the Prof that everything should be reused and recycled, he believes that even dried sludge has its value. "It is possible that it may contain nutrients like a vitamin. It has to be researched further.”

No, I don’t think the idealistic 73-year-old was joking.

Photos courtesy of PUB Singapore.

About the Lee Kuan Yew Water Prize

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.