Scarcity of water is a key driver for reuse of wastewater in many places around the world. Meanwhile, current wastewater practice is challenged to improve on reduction of greenhouse gas emissions, removal of trace organics (including pharmaceuticals) and on recovery potential of valuable compounds. This is where the CoRe Water concept comes in: Concentration and Reuse.
Rethinking the system
Considering all the existing and new challenges imposed on the treatment process of municipal wastewater, there are convincing arguments for rethinking the system. A key element is concentration of wastewater early in the process. What are the reasons for concentrating wastewater first?
- As a general rule in water technology, the more concentrated the liquid stream, the more efficient treatment processes are
- The concentrate can be treated anaerobically, which converts organics into methane
- Recovery of valuable compounds (e.g. nutrients) and energy from the concentrate are favoured
- Trace organics (e.g. pharmaceuticals) are managed more efficiently
- The emission of greenhouse gases (esp. N2O) is significantly reduced
- And last but not least: the clean water flow can be reused in high-end applications
Forward Osmosis: mimicking mother nature
The principle of Forward Osmosis (FO) is a general part of natural biological systems. In our engineered FO process a semi-permeable membrane is placed between the pre-clarified wastewater and the ‘draw solution’ (typically a concentrated salt solution). The osmotic gradient between the two flows generates a water flow through the membrane, resulting in a concentrated feed stream and a diluted draw solution. Next, the diluted draw solution and clean water are recovered, and the concentrate stream is further treated.
Due to substantial flow and quality variations, municipal wastewater is a challenging application for FO technology. Presently we are up-scaling the process. Worldwide, full-scale FO plants are already in operation for treatment of specific industrial wastewaters at capacities >25 m3/h.
The CoRe Water Collab
The Allied Waters Collab CoRe Water includes BLUE-tec, Royal HaskoningDHV and KWR: an all Dutch Collab that combines a strong track record in innovation and FO expertise with design and operational expertise in wastewater practice. We are happy to join you evaluating the potential of the CoRe Water concept in any specific case. Allied Waters: driving the circular economy.