Effect of biological colonization on ceramic roofing tiles by lichens and a combined laser and biocide procedure for its removal

Abstract Biodeterioration damage is an important issue in conservation and restoration of built heritage, especially when ceramic materials are used. Biological colonization of ceramic roofing tiles by lichens is a common phenomenon. However, there are no reports to date of lichens removal from unglazed roofing tiles for conservation purposes. This paper for the first time reveals the results of a combined procedure undertaken to assess the removal of lichens on different kinds of unglazed ceramic roofing tiles by treatments based on both dual sequential laser irradiation and treatment using Acticide ® CF biocide. Three species of lichens were identified: Verrucaria nigrescens , Calogaya decipiens and Pyrenodesmia teicholyta . The chemical and mineralogical composition of roofing tiles were characterized by X-ray fluorescence (XRF) spectrometry, optical polarized petrographic microscopy, and X-ray diffraction (XRD). Laser irradiation was accomplished by applying sequences of nanosecond laser pulses at two wavelengths (1064 and 266 nm). After dual sequential laser irradiation a biocide was applied. To assess the combined effect of both treatments several techniques were used, including stereo and fluorescence (FM) microscopies, scanning (SEM) and transmission (TEM) electron microscopies, and FT-Raman spectroscopy. Chemical composition of the analyzed roofing tiles was shown as a relevant factor regarding the degree of interaction between the biological colonization and the substrate, and hence, the bioweathering effect. The combined procedure has proved to be very effective in ablating cortical layers in all species, or even complete areolae in V. nigrescens , enhancing biocide effect in the thalli of C. decipiens and P. teicholyta , and producing the complete damage of both bionts.

[1]  C. Ascaso,et al.  The weathering of calcareous rocks by lichens , 1982, Pedobiologia.

[2]  Stefano Bertuzzi,et al.  Species- and site-specific efficacy of commercial biocides and application solvents against lichens , 2017 .

[3]  M. Oujja,et al.  Infrared and ultraviolet laser removal of crustose lichens on dolomite heritage stone , 2015 .

[4]  Maria Perla Colombini,et al.  Investigation of the Er:YAG Laser at 2.94 μm to Remove Lichens Growing on Stone , 2009 .

[5]  C. Ascaso,et al.  Application of back‐scattered electron imaging to the study of the lichen‐rock interface , 1994 .

[6]  M. Oujja,et al.  Laser cleaning of terracotta decorations of the portal of Palos of the Cathedral of Seville , 2005 .

[7]  C. Ascaso,et al.  Preparative Techniques for Transmission Electron Microscopy and Confocal Laser Scanning Microscopy of Lichens , 2002 .

[8]  G. Clauzade,et al.  Likenoj de Okcidenta Europo : Le genre Ramalina , 1998 .

[9]  Martin Cooper,et al.  Laser cleaning in conservation : an introduction , 1998 .

[10]  Clifford W. Smith.  The Lichens of Great Britain and Ireland , 2009 .

[11]  S. Tomasi,et al.  UV-protectant metabolites from lichens and their symbiotic partners. , 2013, Natural product reports.

[12]  M. F. Macedo,et al.  Microbial communities on deteriorated artistic tiles from Pena National Palace (Sintra, Portugal) , 2013 .

[13]  P. Nimis.  The lichens of Italy. A second annotated catalogue , 2016 .

[14]  Sergio Pérez-Ortega,et al.  Nd-YAG laser irradiation damages to Verrucaria nigrescens , 2013 .

[15]  X. Sheng,et al.  Characterization of bacterial community inhabiting the surfaces of weathered bricks of Nanjing Ming city walls. , 2011, The Science of the total environment.

[16]  James W. P. Campbell,et al.  Brick: A World History , 2003 .

[17]  P. Pouli.  Laser Cleaning , 2018, The Encyclopedia of Archaeological Sciences.

[18]  Paraskevi Pouli,et al.  Short free running Nd:YAG laser to clean different encrustations on Pentelic marble: procedure and evaluation of the effects , 2003 .

[19]  M. Oujja,et al.  Influence of wavelength on the laser removal of lichens colonizing heritage stone , 2017 .

[20]  H. Edwards,et al.  Vibrational Raman spectroscopic studies of calcium oxalate monohydrate and dihydrate in lichen encrustations on renaissance frescoes , 1992 .

[21]  Mario Mascalchi,et al.  Removal of Verrucaria nigrescens from Carrara marble artefacts using Nd:YAG lasers: comparison among different pulse durations and wavelengths , 2015 .

[22]  C. Ascaso,et al.  THE EFFECT OF DESICCATION ON CELL SHAPE IN THE LICHEN PARMELIA SULCATA TAYLOR , 1987 .

[23]  John Warren,et al.  Conservation of brick , 1998 .

[24]  J. Ranogajec,et al.  Evaluation of the effect of lichens on ceramic roofing tiles by scanning electron microscopy and energy-dispersive spectroscopy analyses. , 2006, Scanning.

[25]  L. Sancho,et al.  The weathering action of saxicolous lichens in maritime Antarctica , 1990, Polar Biology.

[26]  M. Villegas,et al.  Biodeterioration of historic stained glasses from the Cartuja de Miraflores (Spain) , 2006 .

[27]  D. W. O. HEDDLE,et al.  Raman Spectroscopy , 1967, Nature.

[28]  C. Mazzoli,et al.  Hematite nucleation and growth in the firing of carbonate-rich clay for pottery production , 2007 .

[29]  H. Edwards,et al.  Molecular spectroscopic studies of lichen substances 1: parietin and emodin , 2003 .

[30]  Maria Filomena Macedo,et al.  Biological colonization and biodeterioration of architectural ceramic materials: An overview , 2015 .

[31]  M. F. Gazulla,et al.  Relationship between certain ceramic roofing tile characteristics and biodeterioration , 2011 .

[32]  C. Ascaso,et al.  Deteriorating effects of lichen and microbial colonization of carbonate building rocks in the Romanesque churches of Segovia, Spain. , 2009, The Science of the total environment.

[33]  R. Russo,et al.  Influence of wavelength on fractionation in laser ablation ICP-MS , 2000 .

[34]  M L Coutinho,et al.  A multiproxy approach to evaluate biocidal treatments on biodeteriorated majolica glazed tiles. , 2016, Environmental microbiology.

[35]  Giuseppe Cultrone,et al.  Carbonate and silicate phase reactions during ceramic firing , 2001 .

[36]  C. Ascaso,et al.  In situ microscopical diagnosis of biodeterioration processes at the convent of Santa Cruz la Real, Segovia, Spain , 2004 .

[37]  Fernando Rocha,et al.  Mineralogical transformations of calcareous rich clays with firing: A comparative study between calcite and dolomite rich clays from Algarve, Portugal , 2009 .