Circular Challenge, Events, Ondernemen

BlueCity Circular Challenge | The winner takes it all


It’s over…. The students have pitched their blue ideas and the winner of the BlueCity Circular Challenge is announced. The BlueCity Circular Challenge is a six week long project in which students and young professionals, in cooperation with Stedin, Hoogheemraadschap Schieland en de Krimpenerwaard, Gemeente Rotterdam and UPP had to develop a valid business case out of each of these companies waste streams.

During The BlueCity Circular Night the winner was announced for the eyes of about 100+ entrepreneurs and interested Rotterdammers. In this article a brief overview of the presented business cases.


Ons team heeft de Circular Challenge van BlueCity 010 gewonnen🥇🏆!!! Zes weken geleden hebben wij hun voor de uitdaging gesteld om een oplossing te bedenken voor de het afval dat achter de roosters blijft hangen bij het zuiveren van rioolwater. Dit afval verbranden wij nu. Dit kost geld en is niet goed voor het milieu. Deze afvalstroom bestaat voor 80% (!!!) uit vochtige doekjes die niet🛇thuis horen in het riool. Ons team wil deze doekjes inzetten bij groene daken. Het neemt niet alleen veel vocht op maar bevat ook meststoffen waar planten goed op groeien🌱. Samen met het team van studenten gaan we dit idee verder uitwerken en zo snel mogelijk in praktijk brengen! #circulair #duurzaam #duurzaamwaterschap #circulaireeconomie #klimaatverandering

Posted by Hoogheemraadschap van Schieland en de Krimpenerwaard on Freitag, 20. Oktober 2017

Tampons and condoms on your roof? The winning group of students wants to use the waste that is thrown in the sewer as compost for the green roofs in Rotterdam. The compost is – as said – made from waste in the sewer. The tampons – and other waste – get stuck within the filter, which is then burned. But now the students decided to take it and dry the products to create a system to grow plants on for the green roofs. With this environmental and blue idea, they won the challenge!


The studens from business case F_Air are using the waste stream from UPP. The group found out Rotterdam is one of the most polluted cities in The Netherlands. Finding a way to make the city air cleaner by using the green waste from UPP was their challenge. They came to the conclusion they wanted to make an air filter. The filter uses moss to clean the polluted air in – for example – offices.


Stedin is changing the Bakelite energy meters in houses throughout Rotterdam. These meters check how much the house hold is using of electricity. But the bakelite is too old to be used, so Stedin is changing the meters. But what to do with the old bakelite, which is still a good product?

The students decided to use fungi to basicly ‘eat’ the bakelite. That way we no longer have to throw the bakelite away and still be able to do something useful with the waste stream as the fungi changes the bakelite in a way they can use it to make tables.

Repurposing Disposables

The municipality of Rotterdam is using proximally 8 million coffee cups. At the moment, all the cups are brought to the paper processing company who takes the PE – you know, the plastic lining – and throws it in with the reused plastic. But it costs a lot of money and it isn’t completely circular yet. That’s where the students come in. They decided to make cup-holders from the PE and make toilet paper from the paper that is left. This way, the employees from Rotterdam are in for a new way of using the cups and immediately have a great thing to talk about to clients.

Want to learn more about these business cases?

Would you like to read more about the circular challenge, the companies that are involved and the business cases they developed? Please click here Or join Circular Rotterdam: Venture Cafe @BlueCity where the students – and more circular entrepreneurs – will share their ideas.