Meeting the needs for accurate and timely lake monitoring, postulated by the European Water Framework directive, is a relevant problem due to the large number of lakes, their spatial and temporal variability, and often their inaccessibility.
To assist this process, FERRO aims to leverage remote sensing technologies in combination with ground monitoring to assess the current status, vulnerability and resilience of lakes and their catchments to eutrophication. This will allow rapid data acquisition and processing, and a cost-effective universal tool for evaluating water quality at a high spatial and temporal resolution.
Reducing the external nutrient loading of lakes is a major challenge, especially when dealing with non-point (diffuse) loading - such as agricultural or urban runoff from multiple small sources.
FERRO proposes a solution using phosphorus-solubilising biostimulants and microorganisms to increase P uptake from soils, which will reduce the need for P fertilisers, and consequently reduce the P runoff to water bodies. FERRO will also implement additional measures by using a cost-effective continuous flocculation system at lake inflows. Flocculants capture and immobilise nutrients that flow in, depriving algae of nutrients and, therefore preventing eutrophication. The sedimented flocculants can then be recovered for circular use.
Reductions in external phosphorus loading can take time to show results in lakes with large “P legacies” (phosphorus accumulation in sediments). Currently, most in-lake restoration measures to P legacies are focused on suppressing P release from sediments. However, these solutions are not long-lasting as the source of eutrophication is not removed.
FERRO will explore and improve different methods for P extraction and reuse such as a solar-powered pump connected to a recyclable P absorption filter from which P can be recovered and recycled as fertiliser. To achieve this, FERRO will also focus on the development and demonstration of a novel filter material that will enable the recycling of nutrients to agriculture.
The project will also evaluate the feasibility and efficacy of targeted sediment removal from the most nutrient-rich areas (identified through sonar) of shallow lakes, which would allow its extraction with minimal cost and environmental harm. Hypolimnetic withdrawal (removal of nutrient-rich bottom waters) from deeper lakes will also be tested and evaluated.
The solutions developed by FERRO are at high technology readiness level (TRL 5-7) and will be validated in the laboratory and the field. FERRO will rely on a high degree of stakeholder involvement and knowledge transfer to ensure implementation and high impact.
This will be achieved through continuous communication between the consortium and practitioners, facilitated through training, webinars, international workshops, and involving interested regions in adopting FERRO solutions.