CADoS nominated Waterinnovation award 2014

The project CADoS is by the Union of Water Authorities nominated for the ‘Waterinnovation award 2014’ in the category Clean Water.


Waterinnovation award
The Waterinnovation award is an award for innovative waterprojects applicable for the tasks of the water authorities: clean water, dry feet and enough water.

Audience award
This year the audience can also vote for the projects. Vote for CADoS between 5 November and 1 December at

Exceptional ‘sieve’ goes into service at Dutch sewage treatment plant

Innovative project gives used toilet paper a new role

A fine sieve was put into service at the Ulrum sewage treatment plant in the Netherlands on Friday 19 September 2014. It was a special milestone in a project called CADoS (Cellulose Assisted Dewatering of Sludge) in which the public sector, the private sector and research institutions are cooperating with each other. From the sewage the fine sieve extracts cellulose that comes mainly from domestic toilet paper. The cellulose fibres are then used to dewater the treated sludge still further. This process requires fewer chemicals and saves money. Biogas is made from the residual product. It is good for the environment and good for the wallet.

onthulling bord

Over the coming three years there will be an examination of how well this innovative application works in practice and how it impacts on operations at the treatment plant. Various studies will be conducted into the effects of adding cellulose to sludge. The leftover waste – i.e. the sieved matter containing cellulose – will also be scrutinised. A key question is by how many percent this method will increase the biogas yield. Another question concerns the possibilities for using the sieved matter as raw material for such purposes as bio-plastics, filler for asphalting or insulation.

Laboratories and trial site
Experiments will be conducted in several laboratories and at the trial site in Ulrum. The sewage treatment plant of the Noorderzijlvest Water Authority was specially modified for this project. An extra building was recently erected to accommodate the fine sieve. On Friday morning the fine sieve system was put into service in the presence of project partners, regional officials and other interested parties. Bob van Zanten, a member of the executive board of Noorderzijlvest Water Authority, said: “Every year 200,000 tons of paper are used in the Netherlands and flushed down the toilet. But we can do more with toilet paper than you ever imagined. Instead of being waste it’s now a raw material. Sustainability is the objective. For the water authority it opens up the prospect of lower treatment costs. A unique project definitely got underway today.”

Strong cooperation
Research institutions are working in the project alongside private companies and government authorities. The six project partners (Noorderzijlvest Water Authority, Brightwork B.V., Attero, Groningen University, the Water Technology Center of Expertise and the Friesland Water Authority) came together to form a powerful collaborative venture. CADoS is also being subsidised by the three northern provinces of the Netherlands and by a collaborative platform called SNN (North Netherlands, Heading North). Eise van der Sluis, Director of SNN, said: “Innovating is great. Each year we receive numerous good proposals for projects. It’s always difficult to check them against compliance with the conditions for a subsidy. But it was impossible to find fault with CADoS. In fact, CADoS excellently meets the new subsidy conditions of the Northern Innovation Agenda.”

Method measuring cellulose developed

The CADoS process is characterised by the separation of cellulose and its subsequent use for the dewatering of sewage sludge. To optimise the process it is important to find out more about the quantity of cellulose brought in with the wastewater during the day.

After a stock-taking exercise by Groningen University (RUG) it emerged that there was no generally used and reliable method for measuring the cellulose. This resulted in RUG (Lena Faust) embarking on the development of a method, in which she succeeded. There is now a reliable method for measuring cellulose in wastewater and sludge. The method uses the enzymatic conversion of cellulose to glucose, which is easily measurable. Pre-treatment of the sample and use of the right enzyme were also part of the development process. More details about the method can be found in the poster presented at the Cellulose Symposium on 19 June 2014: Poster_Cellulose symposium

Meetmethode concentratie cellulose - RUG

Official start project CADoS 19 September

At Friday the 19th of September from 10.00 till 12.00 AM the project CADoS official starts. You are welcome to enjoy this moment. There are some presentations about the project and you can get a guided tour at the waste water treatment plant.

You can sign up for the event at

Uitnodigingskaart CADoS

CADoS goes international

CADoS technology has gained international attention. Hence discussions has been initiated in the UK and the USA to promote the technology, set up strategic alliances and study particular business cases, with the purpose to generate project leads. Brightwork will be present at the upcoming WEFTEC exhibition (New Orleans, early October 2014) in order to proceed marketing. WEFTEC is the largest annual water quality event in the world.

Website CADoS live!

A project with the world first predicate must also be found in the ‘air’. Therefore, a website is developed about CADoS, which is live since April 11. On this website you can read about the specifics of CADoS, but also about why we start this project. Please read the website and be astonished!

CADoS in a nutshell
The object of the CADoS project is to develop and to build a prototype of the Cellulose Assisted Dewatering of Sludge (CADoS) water treatment concept at the Ulrum sewage-treatment plant. The CADoS principle will be applied to use a new sieving technology innovatively within an existing wastewater treatment process.

Wastewater carried via sewers to the treatment plant contains solid matter that includes a large proportion of cellulose. The cellulose stems from the use of toilet paper. The project will separate the solid matter containing cellulose that is present in the sewage water by means of a fine sieve and will use the separated solid matter for the dewatering of sewage sludge. The CADoS principle is being applied to attempt to reduce significantly the use of chemicals at the treatment plant, to consume less energy and to lower sludge processing costs. CADoS will also increase the energy yield from biogas in the fermentation of sludge.

Water authorities, universities and industry work together in project Cados. The uniqueness of the collaboration is the power of the ‘golden triangle’, and that these parties cover the entire line of water treatment areas. Therefore the effect of theories can be quickly tested in practice. The six parties each have a practical and financial stake in the project, but also each have their own goals and interests.

Latest news
We regularly publish on this website the latest news around Cados, for example milestones or research findings. In order to stay informed, you can view the page ‘news’. On the webpage ‘publications’ you will find the collection of own and press publications. It is also possible to stay informed via the RSS feed Cados. In order to achieve this you can add the address to your RSS reader or click ‘rss’ at the bottom of the website.

The website is still very textually inserted. We will soon post pictures supporting the texts.

Questions or more information?
Do you have questions about Cados? You can find under ‘contact’ contact per partner. If you would like more information about the website, please contact Noorderzijlvest Water Authority: Lydia Balkema 0031 50 309 9581

Hear about Cados at the following symposia

In April and June are symposia where the capture and use of cellulose is central. Cados is from that premise also relevant. You will find per symposium a note below.

From wastewater to new materials
Date: 29 april 2014

Wastewater contains valuable raw materials. What are they? How do you reveal it? Can products be developed with successful market opportunities? These questions play in water authorities and companies in their efforts to recover materials will encourage more sustainable water management and development of new markets.

Several parties – including Noorderzijlvest Water Authority – organize a seminar with workshops for SMEs, where the opportunities to be innovative will be explained.

Toiletpaper from wastewater
Date: 19 june 2014

The recovery of cellulose from waste water is one of the spearheads of the Water Authorities. To achieve this, the Cellulose working group is founded as part of the ‘Raw Materials Factory’. This working group aims to promote the transition from wastewater treatment plant for raw materials in the field of cellulose and eventually closing the chain of cellulose.

In addition to knowledge about the production and valorisation of cellulose from waste water, this symposium has an explicit objective to involve everyone involved in the chain to the subject. Content meets policy, producer meets processor and customer; the wastewater world meets the biobased economy.