B3.- Optimization of the constructed green filters

Name

B3.- Optimization of the constructed green filters

Background

Green filters (also known as constructed or artificial wetlands) are biological filters designed to improve water quality by reducing the amount of nutrients and pollutants it holds. They are also great producers of aquatic vegetation which accumulates carbon and traps sediments. In this way, green filters can be used as carbon traps and, as they are producers of biomass, they also increase the elevation of the land, thus compensating for sea level rises and subsidence. In the Ebro Delta, under the Integral Plan for the Protection of the Ebro Delta (Pla Integral de Protecció del Delta de l'Ebre, PIPDE) two green filters were built with the objective of improving the quality of the water draining from the rice fields. However, these filters do not yet have a suitable management plan in place to optimize their operation.

Goals

The objective of this action is to put the filters to work and optimize not just the capture of nutrients and pollutants but also the build-up of soil and sequestering of carbon.

Where

The two filters, "Illa de mar" and "Embut", are located in two disused rice fields in the Delta. "Illa de mar" is on the northern side of the Delta, whereas the "Embut" filter is on the southern half.

When

Between April-May and November-December, 2015, 2016 and 2017

Expected Results

To find out the optimum rate of water renewal for the filters to generate the maximum capacity of organic matter and the best rate of carbon sequestration, without reducing their capacity to improve water quality.