How Wageningen expertise helps tackle urban challenges

^{Text: René Didde | Photo: Shutterstock}

This article appeared in Wageningen World 2|2025, the magazine of Wageningen University & Research.

Joppe van Driel stands on the banks of the IJ canal in Amsterdam, close to the main train station. He points to a steel cage in the water in which dozens of plastic bottles, packages, foil wrappers, cups, biros and cigarette filters are floating. A brazen grebe tries in vain to get at a plastic bag. 

The cage is a trap in a kind of curtain that extends the whole width of the canal, from 50 centimetres below the water’s surface to 20 centimetres above. The curtain prevents the urban plastic soup from floating out to the North Sea via the IJ and the North Sea Canal. This Canal Cleaner is one of the plastic traps that the start-up Noria in Delft developed. ‘Thanks to Wageningen research, we know 3.67 plastic items a minute flow into the IJ due to the current that arises when the city’s canals are flushed clean every day,’ says Van Driel, programme developer at Amsterdam Institute for Advanced Metropolitan Solutions (AMS Institute). ‘Natural forces such as wind and rain can speed up the rate at which the plastic is carried to the IJ via the city canals. That research also told us that this is one of the main outflow points for all the Amsterdam waterways.’

The plastic soup trap epitomizes AMS Institute’s approach. In this institute, Wageningen scientists work together with researchers from Delft University of Technology, Massachusetts Institute of Technology (MIT) and the municipality of Amsterdam. Master’s students, businesses and project partners in the public sector are also involved in the effort to find solutions for the problems faced by cities. The result is scientific research that is soon put into practice in urban policies. In the 11 years since AMS Institute was founded, it has conducted more than 250 projects, tackling urban problems in six key areas: waste & the circular economy; mobility; climate adaptation; the energy transition; food; and digitalization. AMS Institute also has its own Master’s programme, which has produced around 250 ‘metropolitan engineers’. Moreover, it has nurtured over 100 start-ups.

Costs will fall

‘Now, we are studying how to scale up plastic waste capturing,’ says Van Driel. As one of the AMS Institute programme developers, he relays issues raised by the city of Amsterdam to the universities. The municipality currently spends 3.2 million euros a year on fishing plastic waste out of the canals, often by using boats to clean up hot spots. Those costs will now fall thanks to this study. Other cities with lots of canals will also be able to make use of these results, says Van Driel.

Furthermore, AMS Institute is working on tackling plastic waste at the source. ‘We are in discussions with Amsterdam snack-bar companies on how to prevent and reduce litter. We are also working with biotechnologists in the group headed by the Delft professor (and Wageningen alumnus) Mark van Loosdrecht on biobased alternatives to plastic using organic waste streams from wastewater.’

‘Our institute is unique in the world in being a collaborative venture between universities and an urban municipality,’ says Eveline van Leeuwen. She became AMS Institute’s scientific director in 2020 and is also a professor of Urban Economics at Wageningen. In AMS Institute’s first five years, the scientists and government officials were still ‘sounding each other out’, says Van Leeuwen. ‘We were doing something completely new and had to learn to speak one another’s language, develop trust and build up a reputation.’ They have succeeded, says Van Leeuwen. ‘We have become a “friendly critic” for the municipality.’

The AMS building on the Navy site in Amsterdam – which is still partly in use by the Ministry of Defence but is evolving into the city’s innovation district – houses about 30 principal researchers, who are affiliated with either Delft or Wageningen, along with some 20 PhD candidates and postdocs, half of whom come from Wageningen University & Research. They all collaborate with around 100 researchers at the two universities in the various projects. A further 70 or so people work in teams dealing with programme development, the living lab coordination, prototyping, entrepreneurship, communications and support, among other things.

The AMS building on the Navy site in Amsterdam – which is still partly in use by the Ministry of Defence but is evolving into the city’s innovation district – houses about 30 principal researchers, who are affiliated with either Delft or Wageningen, along with some 20 PhD candidates and postdocs, half of whom come from Wageningen University & Research. They all collaborate with around 100 researchers at the two universities in the various projects. A further 70 or so people work in teams dealing with programme development, the living lab coordination, prototyping, entrepreneurship, communications and support, among other things.

Food grinder

Willie van den Broek, a programme developer at AMS Institute who is affiliated with Wageningen Food & Biobased Research, is working on tackling another common problem for Western cities: collecting organic waste. It is very difficult to collect food leftovers and fruit and vegetable waste separately in densely populated cities. A million people live in Amsterdam, says Van den Broek. ‘They produce about 86 kilograms of organic waste per person per year.’ He is working with a PhD candidate on organic waste collection for high-rise buildings. He has built a food grinder in partnership with Rotterdam, The Hague, Utrecht, Haarlem and the Directorate-General for Public Works. ‘People living in high-rise buildings get a second kitchen sink in which they can shred their banana skins, peel, leftovers, and so on just by pressing a button.’

Water then flushes the organic puree down to an installation in the building’s basement. ‘The waste is dewatered there,’ explains Van den Broek. ‘What remains can be collected by a waste processing company for digestion and composting. We are also looking into more high-grade options, such as using it to make biobased plastics and ingredients for plant food. In Amsterdam, as in many other cities, most new buildings are high-rise flats, so we will be able to install this system in those buildings straight away.’

However, one more problem needs to be resolved before this can be applied at scale. ‘We want to discharge the water extracted from the waste into the sewer system, but that isn’t allowed under the current regulations.’ AMS Institute is now therefore investigating what exactly is in the water in order to find a solution. Van den Broek: ‘In addition, we are looking at ways of reusing this wastewater locally, for example for irrigating or spraying market gardens in and around Amsterdam or for restaurants that grow their own vegetables and herbs in a greenhouse.’

Once a fortnight, Van Leeuwen and her colleague Zwanet van Lubek, AMS Institute’s managing director as of 2024, meet with the Chief Technology Officer of Amsterdam municipality. They also get visits from the heads of the municipal policy departments. ‘They come spontaneously to us with questions, for example on how to generate renewable energy in the city centre without solar panels as those panels would detract from the historical character of the houses along the canals. Aquathermal energy – generating energy from the water in the canals – is one of the options we are investigating.’

Quaysides and bridges

Melanie van der Horst, the Amsterdam municipal executive member with responsibility for Public Spaces, Greenery and Water, sees AMS Institute as a place ‘that translates research into practical applications’. ‘First, we look at what the city needs and then we test solutions directly in the urban setting. If something works, we take it further. If it doesn’t work, we go back to the drawing board and try again.’

In this regard, she praises the collaboration with companies. ‘It means innovative ideas get put into practice more quickly. It isn’t just Amsterdam that benefits; this is invaluable for cities throughout the country and beyond.’ She cites the example of the maintenance of quaysides and bridges. ‘How can we find a smart way to combine sustainability, liveability and biodiversity when upgrading or renovating quaysides? Researchers from various disciplines are working on this together with designers, policymakers and other partners.’ It is one of the fields of expertise of Henk Wolfert, who is affiliated with Wageningen Environmental Research and has been a programme manager at AMS Institute since it was founded in 2014.

After a commission reported in 2019 that Amsterdam’s quays were suffering from a severe shortfall in maintenance and then a quayside wall on Grimburgwal canal collapsed in 2020, Wolfert saw a role for AMS Institute in helping tackle the issue. ‘Five per cent of the quaysides and bridges were unsafe and five per cent were safe, but the alarming news was that the municipality had no idea about the remaining ninety per cent,’ recalls Wolfert. ‘In fact, that applies to the quaysides and bridges in all of Europe’s cities, whether that is Hamburg or Venice. That infrastructure was built over a hundred years ago and its maintenance is likely to get forgotten in the hectic day-to-day routine. As a result, there’s also not much expertise on how to maintain a quay or bridge and how to deal with the pipes and sewers that have been laid over the past hundred years.’

Timeless canals

Wolfert’s involvement led to a spectacular test with a collapsing quay in 2022. Pressure was exerted on this quay, which dated back to 1905 and was due for demolition anyway, by filling containers with more and more water. Sensors recorded detailed measurements of the quay’s movements. The quay was pushed down 15 centimetres. The test cost more than two million euros but has saved well over that amount thanks to the new predictive models for the state of the quays. ‘For example, the municipality was able to remove nearly four kilometres from the expected 200 kilometres of quayside requiring restoration work in 2024,’ explains Wolfert. ‘When you think that building a new quay costs up to 50,000 euros per metre, that could save them 200 million. So the research is definitely worthwhile. In the Timeless Canals project, we are sharing this knowledge with cities such as The Hague, Utrecht, Leiden and Delft. The AMS research budget has increased by a factor of five since the start, partly thanks to the involvement of bodies such as the Dutch Research Council and companies, for example in the building industry.’

When redesigning the canals, AMS Institute and Amsterdam municipality came up with the concept of ‘multifunctional quays’. ‘These new quays also need to last for a hundred years, so we should take into account climate adaptation, the energy transition, water quality and biodiversity,’ says Wolfert. Biodiversity isn’t just about keeping the trees but also about having different species of trees that attract more insects and are better able to cope with both extremely wet and very dry conditions. Wageningen is helping by providing 3D visualizations of how the tree roots grow. Wolfert: ‘Other ways of promoting biodiversity are ferns on the quay walls, water plants that have a purifying effect and 3D-printed concrete tiles that provide shelter and spawning grounds for fish.’ In addition, the researchers are looking at whether heat exchangers in the quayside walls could transfer the energy from the canal water to the pumped water that provides heating and cooling in homes, a solution termed aquathermal energy. That is Delft’s field of expertise. Wolfert: ‘The recurring theme is that we have different disciplines joining forces here in AMS Institute and collaborating in a transdisciplinary way. We all work here on one blueprint, where the energy people say how many houses need to be heated and the aquatic ecologists and plant scientists make sure biodiversity is taken into account.’

The knowledge acquired and the specific solutions could also be applied in other cities with a lot of waterways, stresses Wolfert. ‘Wageningen is often associated with knowledge relevant to the countryside and farmers, but we also have something to contribute to a city like Amsterdam with its power, money, technology and innovation.’

Fostering inclusion

Where possible, AMS Institute also works on projects aimed at improving inclusion in the city. ‘Inclusion is one of the seven key political ideals that can be identified when studying 30 years of municipal coalition agreements,’ says Van Leeuwen. All Amsterdam’s residents (with 175 different nationalities) should feel involved and safe in the city, regardless of their origins and income. A researcher and energy coach at AMS Institute is therefore looking at how smart technology can be used to reduce energy poverty in the city.

Another nice example, says Van Leeuwen, is the reuse of solar panels. ‘We are researching whether second-hand solar panels still function after being dismantled and transported to a new place,’ says Van Leeuwen. ‘Work-study programmes for young people have been designed to tie in with this in the Amsterdam Zuidoost district. The second-hand panels are installed on the roofs of sports club premises, for instance. They are also connected to the Energy Bank, and housing corporations lease them to households with energy poverty.’

The ‘World Vegetable Gardens’ – in a greenhouse that used to belong to a rose nursery on the western edge of Amsterdam – is a good example of inclusion in a food context. Amsterdam folk with Surinamese, Turkish or Moroccan roots grow vegetables they would otherwise have to pay a lot of money for at ethnic grocery stores. Wageningen scientists select the seeds that will do well in an unheated greenhouse in the Netherlands. They are also investigating the question of whether culinary heritage can play a role in encouraging healthier diets.