Abstract
Salt induced deterioration of structures and stones are generally recognized as a frequent and serious problem. The deterioration is especially undesired in relation to cultural heritage as it is impossible to recreate original material (e.g. original murals). By presence of salts in decorated vaults two different techniques are applied: poultices or establishment of climate chambers. Both techniques can result in ion transport away from the valuable surfaces with murals, but satisfying desalination has not been obtained according to conservators from the Danish National Museums mural preservation section in consistence with the present available literature. In the present paper the possibility for salt removal by utilizing a well known and accepted transport process, electromigration, is investigated, i.e. movement of ions in a solution in an applied electric DC field. An experimental laboratory setup was designed to approximate real conditions in vaults and with ion contents corresponding to normal heavily polluted church vaults (1.0 wt% Chloride, added as NaCl). During the electromigration process acid and base is produced at the electrodes due to electrode reactions and in a clarifying experiment with a traditional poultice significant pH changes and an absence of satisfying high desalination effect was measured. The new idea in the present paper was to introduce a calculated amount of buffer components corresponding to the productions during the electrode processes to a poultice (a solid) to minimize the adverse effects and to optimize on the effects. The results showed good ability to retain neutral pH values in the substrate which is of major importance when the method should be applied on existing structures. Also the desalination process continued until a very low and harmless salt content was reached after introduction of the buffer components.
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References
Larsen PK (1999) Desalination of painted brick vaults. PhD thesis, Department of Structural Engineering and Materials, Technical University of Denmark. Series R, no 52, pp 5, 64
Voronina V (2011) Salt extraction by poulticing: an NMR study. PhD thesis, Technische Universiteit Eindhoven, pp 2, 97
Sawdy A, Lubelli B, Voronina V, Funke F, Pel L (2010) Optimising the extraction of soluble salts from porous materials by poultices. Stud Conserv 55:26–40
Lubelli B, van Hess RPJ (2010) Desalination of masonry structures: fine tuning of pore size distribution of poultices to substrate properties. J Cult Heritage 11(1):10–18
Lubelli B, van Hees RPJ, De Clercq H (2011) Fine tuning of desalination poultices: try-outs in practice. In: Proceedings “Salt weathering on buildings and stone sculptures”, Limassol, Cyprus, 19–22 Oct 2011, pp 381–388
Pel L, Sawdy A, Voronina V (2010) Physical principles and efficiency of salt extraction by poulticing. J Cult Heritage 11(2010):59–67
Bøllingtoft P, Larsen PK (2002) The use of passive climate control to prevent salt decay in Danish churches. Tagungsbeiträge “Mauersalze und Architekturoberflächen”, 1–3 Februar 2002, pp 90–93
Larsen PK (2002) The use of passive climate control to prevent salt decay in Rørby church. The study of salt deterioration mechanisms. Decay of brick walls influenced by interior climate changes. European Heritage Laboratories—Rapheäl Project 1999, pp 102–107
Larsen PK (2007) Climate control in Danish churches. In: Padfield T, Borchersen K (eds) Proceedings “Museums microclimates”, pp 167–174
Laue S (2002) Salze und Raumklima in historischen Gebäuden. In: Proceedings “Mauersalze und Architekturoberflächen”, Dresden, Germany, 1–3 Feb 2002, pp 65–71
Friese P, Birkenhofer H (1985) Elektrochemische Entsalzung von Mauerwerk, praktische Ausführung, Entsalzung und Trocknung. Bauphysik 4:105–109
Demberger L (1991) Elektrochemische Vorgänge zur Entfeuchtung von Mauerwerk. Bautenschutz + Bausanierung 14:115–119
Auras M, Melisa G (2002) Kompressenentsalzung – Wirkungsprinzip, Materialien, Anwendung, Fallbeispiele. Salze im historischen Natursteinmauerwerk. IFS-Tagung 2002. Institut für Steinkonservierung e.V. Bericht Nr. 14 – 2002
Friese P, Protz A (2002) Entsalzung von Mauerwerk und Wandmalerei – Transportmechanismen und Beispiele für die praktische Anwendung. Tagungsbeiträge. Hochschule für Bildende Künste Dresden. Mauersalze und Architekturoberflächen. Herausgeber: Heinz Leitner, Steffen Laue, Heiner Siedel, pp 148–153
Rörig-Dalgaard I (2009) Preservation of murals with electrokinetic—with focus on desalination of single bricks. PhD thesis, Technical University of Denmark
Ottosen LM, Rörig-Dalgaard I (2009) Desalination of brick by application of an electric DC field. J Mater Struct 42(7):961–971
Paz-García JM, Johannesson B, Ottosen LM, Ribeiro AB, Rodríguez-Maroto JM (2011) Modeling of electrokinetic processes by finite element integration of the Nernst-Planck-Poisson system of equations. J Sep Purif Technol 79(2011):183–192
Kamran K, Pel L, Sawdy A, Huinink H, Kopinga K (2012) Desalination of porous building materials by electrokinetics an NMR study. Mater Struct 45:297–308
Rörig-Dalgaard I, Ottosen LM, Hansen KK (2012) Diffusion and electromigration in clay bricks influenced by differences in the pore system resulting from firing. J Constr Build Mater 27:390–397
Krenkler K (1980) Chemie des Bauwesens, Band 1 Anorganische Chemie. Springer-Verlag, New York, pp 133–136
Schumann I (1997) Zur nachträglichen Bestimmung der Brenntemperatur und zum Einfluss der Brenntemperatur auf die chemische Beständigkeit von Ziegeln, pp 85–87
Castellote M, Andrade C, Alonso C (2000) Electrochemical removal of chlorides—modelling of the extraction, resulting profiles and determination of the efficient time of treatment. Cem Concr Res 30(2000):615–621
van Nostrand RV, Cook KL (1966) Interpretation of resistivity data. Geological Survey professional paper 499. United States Government Printing Office, Washington
Acar YB, Alshawabkeh AN (1993) Principles of electrokinetic remediation. Environ Sci Technol 27(13):2638–2647
Radeka M (2007) Microbial deterioration of clay roofing tiles. In: Proceedings at the 10th international conference on structural studies, repairs and maintenance of heritage architecture, Prague, pp 567–575
Ottosen LM, Hansen HK, Laursen S, Villumsen A (1997) Electrodialytic remediation of soil polluted with copper from wood preservation industry. Environ Sci Technol A31:1711–1715
Banfill PFG (1997) Re-alkalisation of carbonated concrete—effect on concrete properties. Constr Build Mater 11(4):255–258
Nguyen NY, Chrambrach A (1977) Natural pH gradients in buffer mixtures: formation in the absence of strongly acidic and basic anolyte and catholyte, gradient steepening by sucrose, and stabilization by high buffer concentrations in the electrolyte chambers. J Anal Biochem 79:462–469
Cang L, Zhou D, Alshawabkeh AN, Chen H (2007) Effects of sodium hypochlorite and high pH buffer solution in electrokinetic soil treatment on soil chromium removal and the functional diversity of soil microbial community. J Hazard Mater 142:111–117
Zhou D, Zorn R, Czurda K (2003) Electrochemical remediation of copper contaminated kaolinete by conditioning anolyte and catholyte pH simultaneously. J Environ Sci 15(3):396–400
Atkins PW (1990) Physical chemistry, 4th edn. Oxford University Press, Oxford, p 236
Grimshaw RW, Harland CE (1975) Ion-exchange: introduction to theory and practice. Monographs for teachers. The Chemical Society, London, p 3
Chang R (2005) Chemistry. International edition, 8th edn. Mcgraw Hill, pp 639, 651, 687
Helt HC, Rancke-Madsen E (1991) Gads Fagleksikon – Kemi (Danish). Gads technical lexicon—chemistry, 1st edn. Gads Forlag, p 200
Laidler KJ, Meiser JH, Sanctuary BC (2003) Physical chemistry, 4th edn. Houhton Mifflin Company, Boston, pp 285–287, 291, 986–987
Zimmerman GH, Wood RH (2002) Conductance of dilute sodium acetate solutions to 469 K and of acetic acid and sodium acetate/acetic acid mixtures to 548 K and 20 MPa. J Solution Chem 31(12):995–1017
Larsen PK (1996) Moisture physical properties of bricks: an investigation of Falkenløwe, Stralsund and Hartmann bricks, technical report 343. Technical University of Denmark, Department of Civil Engineering, Building Materials Laboratory
WTA (2001) Merkblatt E-3-13-01/D, Zerstörungsfreies Entsalzen von Naturstein und anderen porösen Baustoffen mittels Kompressen. (Non-destructive desalination of natural stones and other porous building materials with compresses)
Castellote M, Andrade C, Alonso C (1999) Modelling of the processes during steady-state migration tests: quantification of transference numbers. J Mater Struct 32:180–186
Elsener B, Molina M, Böhni H (1993) The electrochemical removal of chlorides from reinforced concrete. J Corros Sci 35:1563–1570
Ottosen LM, Rörig-Dalgaard I (2006) Drying brick masonry by electro-osmosis. In: Proceedings from the seventh international masonry conference, no. 31, CD-romy London, UK
Atkins PW (1994) Physical chemistry, 5th edn. Oxford University Press, Oxford, p C28
Österreichisches Normungsinstitut (1999) ÖNORM B 3355-1 Trockenlegung von feuchten Mauerwerk – Bauwerksdiagnostik und Planungsgrundlagen
Ottosen LM, Pedersen AJ, Rörig-Dalgaard I (2007) Salt-related problems in brick masonry and electrokinetic removal of salts. J Build Apprais 3(3):181–194
Rörig-Dalgaard I, Ottosen LM (2011) Desalination of porous materials by use of buffer electrode units. EPO patent 2276716
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The Foundations Realdania, Velux and Augustinus are gratefully acknowledged for financial support. Lisbeth M. Ottosen and Kurt Kielsgaard Hansen are both acknowledged for proof reading and comments.
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Rörig-Dalgaard, I. Development of a poultice for electrochemical desalination of porous building materials: desalination effect and pH changes. Mater Struct 46, 959–970 (2013). https://doi.org/10.1617/s11527-012-9946-7
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DOI: https://doi.org/10.1617/s11527-012-9946-7