Experimental study of limestone and sandstone sulphation in polluted realistic conditions: The Lausanne Atmospheric Simulation Chamber (LASC)

DRIFTS and Knudsen cell study of the heterogeneous reactivity of SO<sub>2</sub> and NO<sub>2</sub> on mineral dust

“…This is a factor of ten higher that our result for both NO 2 and SO 2 . The SO 2 deposition velocity on limestone and sandstone in the presence of NO 2 has been reported with a maximum of 0.45 cm s −1 (Ausset et al, 1996). A rough estimate of the equivalent uptake coefficient from the deposition velocity can be made using the expression γ =4 ν d /ν m , were the ν d is the deposition velocity and ν m the molecular velocity (Dentener et al, 1996).…”

La composición mineralógica de la arenisca y su influencia en la deposición de dióxido de azufre

“…Other oxides, such as manganese, may also act as catalysts, but in all the sandstones studied the MnO concentration was under 0.02% by mass. Airborne particles such as fly ash may also raise SO 2 deposition rates (20) in sandstone. Soot particles seem to cause an effect contrary to the interpretation given by Ausset et al (20) Debe tenerse en cuenta que el contenido total de hierro no es necesariamente el mismo que el contenido de óxi-dos o hidróxidos de hierro en las muestras; pero en el caso de las areniscas con mayor contenido de hierro la mayor parte del hierro total se encontraba en forma de óxidos o hidróxidos, lo que explica el color marrón rojizo de las areniscas de Maulbronn y Pfinztal (debido a las hematites) y el color marrón amarillento de la arenisca de Donzdorf (debido a la goetita).…”

“…Sin embargo, las partículas de hollín parecen tener el efecto contrario, tal y como interpretaron Ausset y otros (20), al formar una capa protectora sobre la superficie de la piedra. Los resultados del presente estudio ponen de manifiesto que la velocidad de deposición de SO 2 en las areniscas con hematites era de casi una orden de magnitud superior a la de las areniscas sin hematites.…”

Neutron radiography and X-ray computed tomography for quantifying weathering and water uptake processes inside porous limestone used as building material

“…A subvolume of both limestones was analysed in order to try to quantify the pore clogging and pore coalescence due to gypsum formation. A large number of studies have been devoted to gypsum crystallization [17,[24][25][26][27][28]. At rain exposed places, the soluble gypsum dissolves in water and no formation of a thick gypsum crust occurs, resulting in a gradual erosion of the surface.…”

“…Descriptions of various standard weathering tests are available (www.nbn.be); by using those tests, a controlled and well known artificially induced atmosphere can be created [25,31].…”