Publication
Title
Air-pollution-induced chemical decay of a sandy-limestone cathedral in Belgium
Author
Abstract
Different trace- and microanalytical techniques were used in an extensive study to elucidate the chemical deterioration process of the sandy-limestone St Rombouts Cathedral in Mechelen, Belgium. Samples of stones, mortar joints, slates, atmospheric aerosols and gases, total and wet deposition, and water that had run down the cathedral walls, were all thoroughly characterized. At the east side, usually not exposed to precipitation, a 3001000-μm thick outer crust of microcrystalline gypsum was observed, while at the west side, this surface layer was mostly eroded away due to precipitation. At the north and south sides, the crust contains varying amounts of gypsum and calcite. The gypsum is mostly present in a bar-shaped morphology and carbonaceous fly-ash particles were rarely found in the weathering crust. Local stone characteristics seem to be extremely important in relation to the gypsum content of the crust; black samples always have a much higher sulphate content than the corresponding white samples, irrespective of the predominant direction of orientation. The relative contribution of nitrogen- and chlorine-containing pollutants to the total decay process is much smaller than that of sulphur-containing pollutants. Deposition samples collected at the site of the cathedral mostly had a pH of > 5.6, due to the neutralization of the rainwater by alkaline atmospheric constituents. Runoff water and washdown water were enriched in all ions, especially Ca2+ and SO42−, indicating that, indeed, gypsum is the most important weathering product. The suspension in deposition samples and black-well leaching water was highly enriched in silicon-containing particles, while runoff water and white-wall leaching water contained a predominant calcium-rich suspension.
Language
English
Source (journal)
The science of the total environment. - Amsterdam, 1972, currens
Publication
Amsterdam : 1989
ISSN
0048-9697 [print]
1879-1026 [online]
DOI
10.1016/0048-9697(89)90038-7
Volume/pages
78 (1989) , p. 263-277
ISI
A1989R806400021
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identifier
Creation 05.05.2014
Last edited 04.03.2024
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