Article In: orcid, cienciavitae, scopus
Microscopic characterisation of black crusts on different substrates
Science of the Total Environment
— 2017 — Elsevier
Key information
Authors:
Published in
04/15/2017
Abstract
lack crusts on different substrates (carbonate and silicate stones, cement-based mortar and carbonate detrital deposits) in urban environments were characterized microscopically by analysing their morphologies and compositions. The objective of this article is to study the interaction between the substrate and the crust and the influence of the environmental conditions on the crust development. On the one hand, the internal structure and morphology of each sample were evaluated with stereo and scanning electron microscopies. On the other hand, the black crust composition was accessed by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy in backscattered electron mode combined with energy dispersive x-ray spectroscopy. The results of these analytical techniques provided interesting information about the composition and the mineralogical phases present in the collected black crusts. In most of the cases, gypsum was detected as the main component exhibiting different habits. Calcite was also detected in all the evaluated gypsum black crusts; its presence was attributed to different origins. The substrate-crust interaction was also evaluated, contributing to distinguish different crust development processes in relation to the substrate. In carbonate substrates (limestones, mortar and carbonate detrital deposits), it was detected a continuous diffuse boundary related to the replacement of Ca-carbonate by Ca-sulphate, while this boundary was significantly more defined for the granitic stone. This study shows that the substrate, the presence of different construction materials, (e.g. mortars), the motor exhaust particulate substances and the concentrations of atmospheric pollutants, the marine influence as well as biological or other anthropogenic compounds are decisive factors in the development of the black crust. Some ideas about the establishment of conservation strategies are also shown.
Publication details
Authors in the community:
Carla Sofia Almeida da Rocha
ist27936
Manuel Francisco Costa Pereira
ist13225
Publication version
AO - Author's Original
Publisher
Elsevier
Title of the publication container
Science of the Total Environment
First page or article number
291
Last page
306
Volume
584-585
Issue
15
Fields of Science and Technology (FOS)
earth-and-related-environmental-sciences - Earth and related environmental sciences
Publication language (ISO code)
eng - English
Alternative identifier (URI)
https://publons.com/publon/19580389/
Rights type:
Only metadata available