L’intervento di restauro delle superfici musive della scalinata del parco di Villa Ravizza ad Arcore e la sperimentazione per la rimozione della patina biologica con prodotti di origine naturale

In the contest of the conservation intervention on the mosaics surfaces of the early twentieth century that decorate the architectures of the park of Villa Ravizza in Arcore, operations of cleaning, consolidation and re-laying of some fragments in the original place were carried out. Regarding the cleaning phase, the removal of the organic patina from mosaics surface has been performed, using products of natural origin, not traditionally used in the restoration field. The experimentation involved stone tesserae and plasters located in a semi-confined environment, characterised by thermo-hygrometric conditions favourable to the colonization of biodeteriogenic species. In particular, observations carried out by a field microscope pointed out the presence of cyanobacteria, green algae, meristematic fungi, mosses and crustose lichens. With the aim of proposing eco-sustainable restoration practices, specific essential oils were chosen as natural biocidal products: the essence of lavender, of oregano and thyme. These essences previously tested on stone materials, have never been used on mosaic surfaces. The applications have been done by brush on all surfaces, observed and monitored at different time intervals before and after treatment. The positive outcome of the experimentation work shows that alternative cleaning interventions can be carried out to traditional methods, in the perspective of an eco-friendly intervention, whose effectiveness can be detected after more than one year and half from their application.