Artificial wetlands

Artificial wetlands are structures that reproduce in a controlled manner the physical, chemical and biological processes permitting the elimination of pollutants dissolved in the water and normally occurring in natural wetlands. It is a “soft” water purification technique consisting in circulating the polluted water through channels or plots with vegetation. The term pollution refers to any excessive concentrations of elements that do not normally imply any risk but, in excess, cause an alteration in its composition. The plants feed off the organic matter present in the water, reducing its concentration and, therefore, eutrophy. The design varies; water may run off as a free sheet (superficial flow) or under the surface by means of gravel beds (sub-superficial flows). The plant species used and the design depend on the elements that need to be removed from the water for cleansing.

We have developed numerous artificial wetlands for this purification technique. Within the context of the Macrophytes LIFE project, a pilot project was conducted in the Mediterranean alongside the Higher Technical School of Agronomy Engineers at the Polytechnic University in Madrid and Lorca City Council.

The simplicity of its operation and the low operating and maintenance costs mean that these techniques are particularly suitable for implementation in developing countries. We have developed artificial wetlands in such countries as the Philippines, Colombia or the Dominican Republic.

In Spain, different artificial wetlands are used to clean up waste water from small communities or rural housing. There are also infrastructures intended to handle masses of water feeding natural wetlands, such as in the case of the Albufera in Valencia. Here there are three “Tancats” that have been converted into artificial wetlands to clean up the water in the Albufera and also generate habitats that can accommodate bird species, small amphibians and reptiles.

The Tancat de Milia is one of the three artificial wetlands purifying the water for the Albufera in Valencia and it is located in the municipality of Sollana. This natural reserve, previously a paddy field, covers 33.4 hectares and cleans up a volume of 2,500 m3/day.

This wetland abstracts water directly from the lake for purification. It also receives the effluent from the “Albufera Sur” WWTP and applies a final refinement treatment before it reaches the lagoon. In addition, it recreates natural ecosystems that are few and far between in the area and of great value for birdlife such as aquatic warblers or the greater bittern.

The system comprises a sector of sub-superficial flow, a sector with superficial flow and a third sector intended for the recreation of an Albufera in optimal condition, including two islands intended for nesting birds. Since the beginning of the Tancat de Milia and l’Illa, Fundación Global Nature has been involved in the design, construction and management until January 2017.

The Tancat de l’Illa located in the municipality of Sueca follows the same scheme as the Tancat de Milia but on a smaller scale. It abstracts and purifies water from the Albufera and also receives the effluent from the Sueca WWTP.

With a surface area of 14.5 Ha, it treats a volume of 2,000 m3/day and, in view of its extensive plant cover, it is a good breeding area for imperial herons. Since the beginning of the Tancat de Milia and l’Illa, Fundación Global Nature has been involved in the design, construction and management until January 2017.

Desde 1993 dedicados a la conservación de la naturaleza y la funcionalidad de los ecosistemas

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