Shower, cleaning, toilet flushing, industrial production; all processes that use a lot of water. But what happens to the dirt in the water, with all that being flushed away and disappearing into the sewer along with the water?
Every year, we produce approximately 30 kilos of organic material (biomass) per person, which disappears into our wastewater via the sewer system. This organic material is removed from the wastewater and has often been incinerated to this day. But what if this wastewater and components from the wastewater sludge are recycled as raw material for new products? The Novo Nordisk Foundation has allocated 7.4 million euros for a major study called ReThink. With this project, TU Delft, Aalborg University and Aarhus University are taking an important step in the transition to a circular economy.
REThiNK aims to recover extracellular polymeric substance (EPS) from wastewater treatment residues as a new circular biopolymer. Recycling biopolymers from wastewater is one of the options for recycling waste from wastewater. Mark van Loosdrecht, professor of environmental biotechnology and water purification at TU Delft, will, together with other researchers from TU Delft, focus on getting to know the physical and chemical properties of polymers better and better understanding how the microbial production process works. With the acquired knowledge of the polymer properties, it is expected to be able to make all sorts of new materials that can be used mainly in the agricultural, chemical and construction sectors. Mark van Loosdrecht states: “We try to use everything that is now called waste.”
Composition of polymers
EPS can be considered a type of gelatin. There has been some systematic research into polymers because the composition, compared to, for example, DNA, is very complex with a huge number of variables. The grant of the research money from the Novo Nordisk Foundation finally paves the way for good and systematic research into these polymers. “So far, EPS has received relatively little attention, and only simplified, meaningless measurements have been performed because the analysis is very complex. In any water treatment, bacteria use EPS to immobilize themselves. These polymers have potential value for the bio-based circular economy. In recent years, we have been able to research the biopolymers in aerobic granular sludge. We can now extend this to activated sludge: the name of the biomass produced in a water treatment plant during the treatment process, ”says Mark van Loosdrecht.
Activated sludge is a waste product that is still incinerated. It is expected that in the future it will act as a raw material in a circular economy that can supply, among other things, phosphate and energy. In particular, the production of biopolymers could make this processing into raw material economically feasible. Over time, it can replace the oil-based polymers now used in industry. These are, for example, composite materials for construction, or flame retardant coatings.
The research is carried out with a team consisting of leading researchers in analysis of the polymers, physical and chemical characterization of the polymers, microbiology of the EPS formation (TU Delft), genetic characterization, physiology of EPS formation (Aalborg University) and polymer processing and NMR characterization (Aarhus university). In short, the results of the research create a gateway for activated sludge to the global biopolymer market, increase the sustainability of wastewater treatment plants and generate a new, abundant and inexpensive raw material for the circular economy.
Read here the message from the Novo Nordisk Foundation about all candidates who have received funding from the NNF Challenge Program for 2022.