The ashes of Etna, from waste to resource for the circular economy

The Sicilian councilor for energy and public utility services he signed a decree that will allow the volcanic ash emitted by Etna to be used in a circular perspective, or rather, using them in production cycles as a replacement for other raw materials.The measure, in particular, indicates the procedures that municipalities and companies will have to follow for the valorization of usable ashes deposited on roads, roofs and other open areas.«From a problem for municipalities, for cleaning and disposal, volcanic ash can become a resource for companies that will be able to use it in the production phases», explained the councilor underlining that, according to national legislation, volcanic ash are excluded from waste regulation."We will launch a communication campaign to raise awareness among private citizens of a collection of volcanic ash that encourages its reuse," he added.

The guidelines for the sustainable reuse of volcanic ash were welcomed positively by the President of the Region Renato Schifani, who also highlighted the precious contribution of the work carried out by the technicians of the regional department with those of ARPA, of the Catania section of the Institute national team of geophysics and volcanology and of the civil engineering department of the University of Catania.But exactly what could be the new life of the Sicilian volcanic material?An indication comes from the project REUCET – Recovery and use of Etna volcanic ash – concluded in 2020 and financed by the Ministry of the Environment with over 70 thousand euros.The most promising results were obtained in the use of ash for ceramic uses, as products are approximately 20% lighter than conventional ones.The potential in the creation of covering mortars and insulating panels is also interesting, thanks to the high porosity that characterizes pyroclastic products.The researchers also evaluated the creation of innovative materials to contain pollution, as well for the environmental recovery of degraded areas.Overall, while recognizing certain limitations, the volcanic material from Etna could find use in the creation of concrete, plasters, traditional brick products, road foundations and some geotechnical works.

The real turning point, however, lies in transforming a problem into a resource and, more specifically, in reducing costs for local administrations.The disposal of Etna's volcanic ash, if sent to landfill, it costs around 120 euros per ton, to which must be added the hundreds of thousands of euros necessary for the collection of ashes from the streets, gardens and roofs of buildings.So far, however, a limit has been imposed by the regulatory status associated with volcanic ash which, in fact, does not consider it waste.Therefore, there is no procedure for its recovery.Only when it covers the road surface does the ash fall within the definition of waste and is assigned a corresponding code by the competent authority.The step forward made in recent days, among other things, would thus allow us to overcome this obstacle.The relevant decree will be published shortly on the institutional website of the Sicilian Region.

[by Simone Valeri]