Abstract
Al- Rifa'i Mosque is one of the most important mosques in cairo. It suffers, like most of the historical buildings sited in urban areas, from many degradation phenomena related to the high level of pollution, especially soiling and formation of the black crusts on the facades of buildings and monuments, which threatening their conservation.
In order to detect the morphological characteristics and the chemical and mineralogical compositions of these degradation products and to identify the pollutant sources and assess their impact on the stone material, an analytical study was conducted on the black crust samples collected from the external façade of the mosque. For a complete characterization of the black crusts, several analytical techniques were carried out , including stereomicroscopy, Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS), X-ray diffraction, Fourier Transform Infrared spectroscopy (FTIR) and Raman spectroscopy.
The results showed that black crusts represent the most frequent and damaging surface degradation products affecting the walls of the mosque. Furthermore the environmental pollution resulting from industrial activities and vehicle traffic has been identified as the main polluting source in Cairo city.