Municipal wastewater contains valuable substances such as organic matter, nutrients, and cellulose, which will be recovered and valorized in the EU-funded project SMART-Plant .
After the construction phase, two of six pilot plants are already in operation that demonstrate the recovery of materials in a technical scale. A filtration process for raw wastewater was commissioned at the wastewater treatment plant Geestmerambacht in the Netherlands, which will extract up to 400 kg per day of cellulose from the water that can be valorized in the construction industry or as an additive to composite materials.
At the same time, the cellulose extraction will improve the performance at treatment plant, where the fibres can cause operational problems and have to be disposed with the sludge. The wastewater treatment in Manresa/Spain follows another approach: specific bacteria are enriched during biological treatment of wastewater with a dedicated control strategy to produce biopolymer (PHA) from the organic matter of wastewater. This specific bacterial sludge can be separated after treatment to extract the biopolymer. PHA is a raw material for many products in the chemical industry, and can also be used together with recovered cellulose to form bio-composite materials. In the course of the project, KWB will apply Life Cycle Assessment to evaluate the environmental impacts and benefits of these approaches for material recovery from wastewater.
picture (copyright Cirtec B.V. 2017): Pilot plant for cellulose recovery at WWTP Geestmerambacht (NL).