Entering the Circular Economy: Recovering of Resources from Industrial Wastewater
ZERO BRINE
- DLR has published open source simulation software to calculate costs and energy requirements to accompany the ZERO BRINE project.
- Background to the research: Although the treatment of wastewater is expensive, most wastewater contains valuable substances such as salts or metals.
- In terms of efficient resource utilisation, there is also an interest in returning usable raw materials to their respective production processes.
- Focus: Energy, system modelling, sustainability
Wastewater from industrial plants is a burden on the environment and health worldwide. Treating it is expensive and is considered a global challenge. At the same time, most wastewater contains valuable substances such as salts or metals. The German Aerospace Center (DLR) has analysed the extent to which an economically attractive circular economy approach can be developed in wastewater treatment through the recovery of resources as part of the ZERO BRINE research project funded by the European Union. Results from exemplary case studies show: With a decreasing environmental impact, competitive operations can be realised by selling recovered recyclables. The corresponding simulation models have now been published freely available as open source software.
Several existing innovative technologies were considered in the ZERO BRINE project, which aim to recover end products of high quality and sufficient purity. They were applied in different process industries ranging from mining to seawater desalination and textiles. "In all cases, wastewater treatment follows not only ecological and economic interests, but also the aspect of efficient resource use," explains Dr Thomas Pregger, head of the ZERO BRINE team at the DLR Institute for Networked Energy Systems. "Accordingly, innovative treatment chains require technologies that are energy- and cost-efficient and ideally pursue two goals: the extraction of clean water and of usable raw materials, and in each case their return to production processes."
Techno-economic evaluation as a decision-making aid
For a comparative and industry-independent analysis, the researchers were able to draw on the methods for model development and techno-economic evaluation established in DLR's energy system analysis. On this basis, software models were developed with which not only individual technologies such as nanofiltration, crystallisation, electrodialysis or reverse osmosis can be mapped, but also their interconnection into treatment chains. The processes can be simulated using detailed process equations so that their energy consumption as well as the costs of the purified water and the recovered raw materials can be determined. "In this way, DLR provides knowledge to support investment decisions in industry and business," says Pregger, emphasising the high practical relevance of the project results.
Case studies show great potential
An initial application of the simulation software was carried out in case studies using data from pilot plants that were set up and operated by project partners in four large European research centres (so-called "Brine Excellence Centers"). In this way, wastewater treatment plants for a coal mine in Poland, the textile industry in Turkey and for an industrial water desalination plant in the Netherlands were investigated. With the focus on the use of renewable energy for desalination plants and their integration into future energy systems, this topic will also play an increasing role at DLR in the coming years.
Knowledge and technology transfer through open source
With the open source publication under the name "ITEMS - BrineTechTools", the last step of the work has now been successfully completed. The simulation software is now freely available to interested parties from research, industry and business. "With this, we are realising our goal of supporting research on circular economy approaches and opening the door to cooperations for further development," says Pregger.