A new tool from Avans University of Applied Sciences could help water sector decision making to recover valuable resources from wastewater treatment plants.
Recovering valuable resources
Avans University of Applied Sciences in the Netherlands has developed a tool to provide information about the recovery of five specific carbon-based materials in wastewater.
The tool is part of the Interreg North-West Europe WOW! Project, which is looking at the valuable resources that can be recovered from sewage treatment plants.
Already being tested by UK water utility Severn Trent, the tool is freely available to download and aims to provide information to help the recovery of five specific carbon-based materials.
“The tool will tell the user what recovery technologies meet the necessary criteria to make the recovery feasible and or not.”
This includes polyhydroxyalkanoates (PHA), which is a fully biodegradable bioplastic that can be produced from fatty acids by bacteria that are present in sewage.
The second is the production of biodiesel from lipids, such as oils and fats, and the third is the production of bio-oil, bio-char and acetic acid from pyrolysis of cellulose.
How the tool works
Bespoke parameters from treatment plants can be entered, including total capacity, the presence of primary treatment and the amount of wastewater being handled households.
The tool then identifies which recovery technology is best suited for the carbon recovery of the minerals present in that wastewater.
In addition, the tool will tell the user what recovery technologies meet the necessary criteria to make the recovery feasible and or not.
Information is also provided about the other processes in a sewage treatment plant that can be affected by the application of one of the recovery technologies, including the technical, ecological, economic and social aspects of each technology.
Creating a new market
Being able to identify and re-circulate the valuable minerals for our sewage is one barrier to overcome but another challenge will be creating a market for these PHAs.
A current project that is seeking to forge this market is PHA2USE, where a demonstration plant will be built to get the marketing of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) off the ground.
In the Northern Netherlands, the ‘Circular biopolymers value chains for PHA and Cellulose’ project has been running since 2017 under the banner of BERNN, the partnership of the Groningen University and the northern universities of applied sciences.
“This is about ending the chicken and egg discussion,” said Joâo Sousa, head of emerging technologies at Paques, one of the parties in the consortium behind this project, which also includes five water boards.
At the recent Fats, Oils and Grease (FOG) Summit 2021, industry thought leaders discussed the potential of viewing FOG and sewage as a resource that could be better utilised - with oil and grease distributor Quautra claiming the industry is "throwing money down the drain, literally".