The TDT-BioART project: innovative techniques for the diagnostics and treatment of biodeteriogens in artistic and archaeological assets

The TDT-bioART project, funded by the Regione Toscana in the frame of the Regional Call POR FESR 2007 - 2013, consisted in a feasibility study of novel methodologies for the diagnostic and treatment in the field of the cultural heritage. The methodologies investigated fulfil two fundamental requirements for this field of application: non-invasiveness and treatment effectiveness. The project focused on issues concerning the biodegradation of artistic, architectural and monumental surfaces, and dealt with techniques and methodologies for both diagnostics and treatment, using however an unconventional approach. An additional objective of the project was to constitute an European network aiming to outline an international research project for the definition of intervention protocols on works of art, based on the best available technologies (BAT) and on the excellence of know-how in this field. Regarding the diagnostics phase, and particularly its early warning capabilities and non invasiveness, the TDT-bioART project has addressed a feasibility study for the transfer of laser induced fluorescence (LIF) techniques, and specifically the fluorescence lidar technique, to the early detection of biodeteriogen colonies on artistic surfaces. For this purpose two research activities have been carried out: 1) preliminary assessment of the effects of low-fluence laser radiation on different types of mural paintings. 2) fluorescence measurements on substrates inoculated with biodeteriogens, in order to assess the feasibility to transfer the fluorescence lidar remote sensing technique - already successfully applied to the detection of biodeteriogens on outdoor monuments - to the remote diagnostics of extended surfaces, even in full sunlight. Regarding the conservation treatment of biodeteriorated artistic assets, the project has addressed a feasibility study on the treatment using microwave radiation. This technique, already successfully applied for the disinfection of xilophage insects in artistic ligneous artefacts, has been applied to the treatment of stone materials colonised by black fungi and lichens and of painted surfaces attacked by micro-fungi colonies in hypogeum sites. The peculiar characteristics of this physical treatment - with respect to other treatments - are: - feasibility of localized treatments by means of the study and implementation of ad hoc applicators; - feasibility of different treatment depths; - elimination of living organisms and their reproductive and resistance forms; - low risk for operators (non ionising radiation). Besides studying thermal-electromagnetic models for the assessment of the interaction with the substrate, we also carried out experimental tests concerning the heating of stone due to the microwaves (acceleration/triggering of decohesion processes) and of mural paintings (pigments and surface pattern alterations). Results open good prospects for the applicability of microwave-based treatments in this field.