Advantages of using microbial technology over traditional chemical technology in removal of black crusts from stone surfaces of historical monuments.
This study compares two cleaning methods, one involving an ammonium carbonate-EDTA mixture and the other involving the sulfate-reducing bacterium Desulfovibrio vulgaris subsp. vulgaris ATCC 29579, for the removal of black crust (containing gypsum) on marble of the Milan Cathedral (Italy). In contrast to the chemical cleaning method, the biological procedure resulted in more homogeneous removal of the surface deposits and preserved the patina noble under the black crust. Whereas both of the treatments converted gypsum to calcite, allowing consolidation, the chemical treatment also formed undesirable sodium sulfate.
Cappitelli
Francesca
F
Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy. francesca.cappitelli@unimi.it
Toniolo
Lucia
L
Sansonetti
Antonio
A
Gulotta
Davide
D
Ranalli
Giancarlo
G
Zanardini
Elisabetta
E
Sorlini
Claudia
C
D001108:Architecture; D001154:Art; D001673:Biodegradation, Environmental; D001709:Biotechnology / Q000379:methods*; D002119:Calcium Carbonate / Q000737:chemistry* / Q000378:metabolism*; D002133:Calcium Sulfate / Q000378:metabolism; D002254:Carbonates / Q000737:chemistry; D003116:Color; D003252:Construction Materials / Q000382:microbiology; D016969:Desulfovibrio vulgaris / Q000378:metabolism*; D004492:Edetic Acid / Q000737:chemistry; D007558:Italy; D008855:Microscopy, Electron, Scanning
D002254:Carbonates; D004492:Edetic Acid; D002119:Calcium Carbonate; C040502:ammonium carbonate; D002133:Calcium Sulfate