Professor Mark van Loosdrecht is chair professor in Environmental Biotechnology at the Delft University of Technology, in The Netherlands. In brief, his research focuses on wastewater treatment using bacteria. Also, he is one of the panel experts at our webinar Water Solutions #2: Reuse, Recycle & Recover (April 30, 15:00-16:15 CET, register here. As an academic expert in resource recovery from municipal wastewater he will share his perspective on our webinar’s main topic. This interview with the amicable professor is a taster of what you can expect April 30th.
Mark: “There are three things you can do with wastewater. The first, often dictated by water shortage, is to treat it to be used as drinking water. The second one is to win energy from water, which has a more environmental purpose. However, we could also see sludge as a source of raw materials.”
Sludge is near-worthless… or isn’t it?
Despite widespread recognition that we need to treat sludge, there is one major hurdle that still needs to be overcome. Nobody wants to pay (much) for sludge. That makes sludge near-worthless, in terms of monetary value.
Mark: “I am fascinated by Microbial Ecology and how it can be used in the design of new processes for wastewater treatment and waste-to-product processes. The research has a focus on biofilm processes, conversion of nitrogen compounds and phosphate and microbial polymer production. Every year, The Netherlands alone produces approximately 15 kg per person per year of it. And we are only a small country. Imagine what the waste is at European, or even global scale. In some countries it is still spread on fields as fertiliser, within the rules and regulations. But what do we do in countries were this is not allowed? If utilities even struggle to give it away for free, how on earth will we create value?”
Kaumera, the versatile
Hope is on the horizon, though. Around 2 to 4% of sludge contains phosphorus, from which struvite can be recovered and sold for as much as £300 per tonne for use as fertiliser.
Now, Mark and his team have discovered a new material: Kaumera. “We have found a material that we can take out of the sludge, which has a certain potential market value, and which can make treatment plants financially stable in itself and not depend on governments’ tax systems”, says Mark. “We named it Kaumera https://kaumera.com/english/, which means ‘chameleon’ in Maori, the language of the original inhabitants of New Zealand. The chameleon is known for its colourful transformation and adaptability. This makes the chameleon a beautifully flexible, effective and versatile animal.
The material Kaumera is equally versatile. The extracted material can be used in agriculture, since it has a strong water binding capacity. Kaumera can change the textile industry: it makes fabric absorb the dye more efficiently, thus reducing the volume of water needed in production. It is also a non-flammable material (up to 1500°C), which makes it usable in both textiles and construction materials.”
The recovery of Kaumera from wastewater takes place within the National Kaumera Development Programme NKOP. In this programme, the Vallei and Veluwe Water Authority, Rhine and IJssel Water Authority, the Dutch Foundation for Applied Research in Water Management (STOWA), the Royal HaskoningDHV engineering consultancy and Delft University of Technology work closely together.
All parties contribute part of the knowledge and expertise needed to recover, process and market the new raw material. From laboratory research to full scale recovery. In this way, the Water Authority, the scientific community and the business community work together on a sustainable, circular economy.
Booming sludge industry
Extracting raw materials from wastewater and then sell it: it seems like a hidden goldmine. Could wastewater treatment plants become millionaires now? Mark: “Well, who knows haha, but that might be a step too far. Utilies however could become selfsufficient, that is an interesting perspective. However, we are not there yet. At the moment, winning raw materials from sludge is more expensive than extracting oil. On top, wastewater has an emotional value: people don’t want to use the water they just flushed down the toilet. And moreover, many, many directives, protocols and assurance schemes create a very complex legislative framework. Unravelling this is easier said than done, and not too many investors are keen on financing a process like this. But I’m hopeful the value of sludge will be recognized on a broad scale and we can put it to positive use. If we can create products that have a true added economic value, there will be a marketplace and people will be willing to pay for it.”
AIWW Webinar Water Solutions #2: Reuse, Recycle & Recover
Want to join Mark and the other panellists (Dimitris Xevgenos, Nynke Hofstra and Jan Willem Vosmeer) in their discussion? Please attend our webinar on April 30 15:00-16:15 CET, register here.