PROJECT DESCRIPTION
BACKGROUND
Water scarcity is no longer limited to isolated instances in few regions of Europe, it has become a concern across the whole EU, with one third of its territory experiencing water stress. Water reuse has been highlighted as the most sustainable alternative to the use of freshwater sources, both in terms of cost and environmental impact. However, wastewater salinity is an ongoing challenge in wastewater treatment (WWTP) and reclamation (WRP) plants where collectors receive industrial brines, agricultural runoff waters and/or marine intrusion. Conventional WWTP or WRP are not designed for salinity removal, which becomes a limiting water quality parameter in water reuse.
OBJECTIVES
The overall objective of LIFE CONQUER was the demonstration of an innovative water reclamation process based on the use of Smart Nanofiltration (NF) that divides salinity and nitrates, to obtain a reclaimed water rich in nutrients. This was expected to be suitable for re-use in irrigation. Additionally, with the dissolved salts removed by concentrating them into brines, the project partners demonstrated the use of Mono-Selective Electrodialysis Reversal (MS-EDR) and 3D granular anodic Electro-Chlorination (EC-3D) to transform them into valuable by-products needed in industrial processes (e.g. sodium hypochlorite).
The project helped in implementing circular economy principles in the field of wastewater, in complying with the requirements of the EU Water Framework Directive and in line with the regulations of water reuse.
RESULTS
The overall objective of LIFE CONQUER was the demonstration of an innovative water reclamation process based on the use of Smart Nanofiltration (NF). This technique produces 2 flows: the first with nitrates and the other with salts (brine). The flow rich in nitrates (rich in nutrients) was used directly for urban irrigation, while the flow rich in salts was processed to be further concentrated to extract valuable by-products needed in water drinking processes (e.g., sodium hypochlorite).
2 pilot plants were constructed for this, namely, a smart nanofiltration plant (including a smart NF digital tool) and a brine valorisation plant. The smart nanofiltration plant was in operation 22 months (January 2023 – October 2024), treating 175 200 m3/year of water and producing 140 160 m3/year of reclaimed water for irrigation. Its functioning entailed significant energy and carbon footprint savings, respectively of 15 418 kWh/year and 4.2 tonnes CO2eq/year emissions. However, it was not possible to optimise the brine concentration unit of the brine valorisation plant during the project, so other solutions are being explored for concentrating the brines. In any case, the beneficiaries produced 0.6 tonnes of sodium hypochlorite/year.
Despite many problems faced during the implementation, beneficiaries were able to demonstrate technical, environmental and economic feasibility of the smart nanofiltration solution. However, this was not possible for the brine valorisation unit, presenting more replication challenges due to technical hurdles and site-specific requirements. Taking this into consideration, the replication plan was conceived with 3 replicas for the nanofiltration unit in the 5 years following the project’s end date. In addition, the beneficiaries plan to continue operating the smart nanofiltration plant, increasing its production to 315 360 m3/year thanks to an expected increase in water availability.
As far as innovation is concerned, the beneficiaries filled a patent application (EP4389938A1) for the "ELECTROLYSIS CHAMBER" (one of the elements of the brine valorisation unit) with the European Patent Office.
