Wetenschap - 30 april 2015

Better new world

It was fifty years ago that the first Wageningen professor of Water Purification was appointed. A master stroke, as it turned out. Since then many inspiring inventions have contributed to better management of the environment, and of water in particular. But what is ahead now?

It was in 1961 that 17-year-old Bram Klapwijk came to Wageningen to study. After a somewhat disappointing introduction to land development, Klapwijk decided to take the brand new specialization in water purification, established in 1962 by the land development department. ‘Professor of Land Development Frans Hellinga and professor of Microbiology Eppe Mulder noticed that the waste water from the dairy industry was increasingly causing problems,’ recalls Klapwijk. In 1965, now 50 years ago, the new department became a fact and Pieter Fohr became the first professor of Water Purification.

Only in 1970 was the degree programme redesigned to cover the field of Environmental Health. It was called Water Purification, however. ‘That was really an administrative error,’ says Klapwijk. ‘Environment meant more than just water. The name did not do justice to the contents.’ After all, besides Water Purification, there were also already departments of Air pollution and Soil Science (including fertilization studies). Bram Klapwijk had been working as a scientist in Water Purification for two years at that point. He was not only the first student of environmental sciences, but also the first PhD graduate, one of the first lecturers and the first study coordinator. ‘I am the last living scientist from the first batch,’ says the now 70-yearold Klapwijk.

The great thing about the department was that it always addressed real contemporary problems, says Klapwijk. And there were enough of those in the early nineteen seventies. The Rhine was an open sewer, the smog in the area around the mouth of the Rhine was literally breathtaking, and citizens were already worrying about the dumping of waste to fill ditches. The Wageningen environmental programme attracted socially engaged students who were driven by the revolutionary spirit of the nineteen sixties and the first stirrings of environmental awareness, and eager to ‘do something about the environment’.

These students were witness to what was undoubtedly Wageningen’s most brilliant contribution to a better environment: the invention of a compact reactor in which micro-organisms purified waste water not with a lot of oxygen but precisely under oxygen-free conditions. And as a byproduct, the organisms produced energy in the form of biogas (methane and carbon dioxide). The instigator of this anaerobic water purification method was the Technical University of Delft (TU) graduate Gatze Lettinga, who came to Wageningen in 1970 with precious little knowledge of microbiology. Even today, Lettinga still comes in for prizes for his contribution to science.


More than water

There is more to environmental health and technology than water. Professor Daan Kromhout is an authority in the field of food and environment- related public health research. He was recently made a knight of the Order of the Dutch Lion in recognition of his ‘exceptional services to science’. Epidemiologist Bert Brunekreef – currently at Utrecht University – has gained a name globally as an expert in the field of air pollution and health risks, related to fine particles in particular. Toxicologist Jan Koeman and his successors such as Ivonne Rietjens and Tinka Murk are seen as solid scientists and often consulted on the toxicity of environmentally harmful substances. Soil scientist Frans de Haan was already warning against the unbridled use of fertilizer on farmland in the nineteen seventies. But it took until phosphate-saturated land and surface water were facts before his scientist’s insight led to government intervention. More recently, environmental policy scientist Simon Bush is has had a lot of influence worldwide on fisheries and fishing policy, not least through the development of new labelling and certification systems.


World famous
Anaerobic water purification put Wageningen environmental research on the map. Today there are more than 3000 of those reactors around the world. They are a lucrative product for several Dutch companies, including Paques in Balk and Biothane. Many industrial companies purify their waste water with these reactors without sacrificing expensive space to large purification and sedimentation basins. Another product of this research was the desulphurization of gases.

The nice thing about these processes is that they are of use to the Third World too. Kitchens in Kenyan slums work on biogas made from fermented sewage from latrine blocks. For many years, Professor Grietje Zeeman has been studying decentralized sanitation, which is a kind of mini-anaerobic purification of toilet water at the level of a row of houses or a small housing estate. Promising results have been achieved in Sneek in the northern Netherlands, where toilet waste fermentation takes place in a few hundred houses.

If legislation is changed to make it permissible to spread minerals such as nitrogen and phosphate extracted from fecal material on the land, these ‘secondary fertilizers’ could further reduce the use of artificial fertilizer in agriculture. The biogas is used locally and the Wageningen research is very compatible with the recent trend towards generating more energy locally (wind turbines, solar panels and biomass) and marketing it locally, through energy cooperatives for instance.

There were enough problems in the early nineteen seventies. The Rhine was an open sewer

When it comes to aerobic water purification too, Wageningen researchers have successfully developed processes for removing phosphate and nitrogen from sewer water. And a third option is quietly under development, combining aerobic with anaerobic techniques. A good example of this is the Nereda reactor designed by Wageningen graduate Mark van Loosdrecht and his Delft research team. In this process, concentrated clusters of bacteria first store waste materials from the water as fat in their cells, in an anaerobic phase. When the fattened up bacteria are then given oxygen for a while, they use the fat for their growth. They form granules and extract nitrogen and phosphate from the water, then proceeding to sink nicely to the bot tom of the reactor. The granules can easily be stripped of phosphate which can then be reused in the fertilizer industry.

‘We are now on the brink of developing such processes to the point where we will be able to extract traces of drugs such as Diclofenac and antibiotics from the water,’ says professor Huub Rijnaarts. Together with professor Cees Buisman, he now leads Environmental Technology, as the research group has been known since 1989. ‘Because although the bulk of the water pollution has decreased massively and the Rhine is no longer an open sewer, we are still getting more and more indications that a lot of microlevel pollution, which gets into the water through the use of chemicals and drugs, forming a chemical cocktail there, has a negative impact on aquatic life,’ says Rijnaarts. ‘And that in turn affects our food that comes from there, and thus our own health too.’

In the coming years new technology will be added to the spectrum, as Annemiek ter Heijne agrees. She is seen as the bright new star in the Environmental Technology firmament. Together with Buisman and Water Technology Institute WETSUS, with which Environmental Technology collaborates intensively, Ter Heijne works on the ‘microbial fuel cell’. ‘When we hang electrodes in the waste water, micro-organisms stick to them,’ she explains: ‘They purify the water, producing electrons of their own which we can use as electricity.’ A variation on this principle has already received quite some publicity. The company Plant E works with bacteria which generate electricity on the roots of plants in a field. There are two of these commercial reactors in Ede and Zaandam.

Astonishing as it may seem, the little organisms can do the opposite trick as well. ‘If we feed the micro-organisms with a bit of electricity and some CO2 from the air, they produce methane. That could provide a solution in certain situations, such as periods of overproduction by solar panels, when the surplus electricity could be converted to gas. That is easier to store and to transport,’ says Ter Heijne. Another option would be to go down the bioplastics route.

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Circular economy
According to Rijnaarts, these possibilities are going to make environmental technology increasingly important, not just in the modern forms of the familiar water purification and waste reduction but also in the form of a complete supply of energy and raw materials. Rijnaarts: ‘We shall make more and more of a contribution to closing the cycle between waste and food. That will no longer only take place in the countryside, but will also start playing a role in the cities. I predict more and more urban systems engineering, in which technologists work with builders, architects and landscape architects to shape the circular economy in the cities of the future.’

So it is a good thing that the Wageningen environment programme not only attracts diehard natural scientists but also offers a programme for future experts in Urban Environmental Management, to mention one relatively new MSc programme. Collaboration with social science disciplines such as economics, sociology and policy studies is indispensable too, realizes Rijnaarts, in efforts to get the concept of ‘closing the cycle’ across to politicians and the general public. ‘As technologists we engage in intensive multidisciplinary collaboration with the ‘Leeuwenborgh disciplines’ in the research school Wageningen Institute for Environmental and Climate Research (WIMEK),’ says Rijnaarts, who is director of this school too.

Professor of Environmental Policy Arthur Mol goes so far as to call this multi- and interdisciplinary collaboration one of the high points of the last 30 years. ‘A cautious start was made on it in the early nineteen eighties, partly through the educational changes that were called the ‘Wageningen Spring’. In the nineteen nineties, this collaboration was institutionalized further. Nowadays we couldn’t imagine life without interdisciplinary research and we have established not just very strong research groups but also good interdisciplinary education.’ Mol thinks environmental research will expand into new territories in the coming years.

‘Take marine research, for instance, and in the polar regions, or in metropolitan cities, also involving and employing lay citizens in scientific research.’ The recently launched collaboration Amsterdam Institute for Advanced Metropolitan Solutions (AMS) with TU Delft is an example of the latter concept. Mol is one of the four members of the board of AMS. Mol also predicts a further expansion of social science- oriented environmental research. Because it is all very well to come up with nice technical inventions, but they do need to be accepted and actively adopted by the general public. These kinds of ‘governance aspects’ are crucial, says Mol. ‘The complexities for further sustainable development lie in the behaviour of individual citizens or groups, in how well institutes function, and in collaboration between countries. We need to be more aware of these things.




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