A method for the analysis of the chemical composition of ancient mortars is proposed. The use of the hot hydrochloric acid attack in order to carry out a separation of the binder and the aggregate is discussed. Different types of mortars of Pamplona Cathedral are analyzed. Traditional chemical methods and atomic emission spectroscopy are employed. The mineralogical studies have been carried out using X-Ray Diffraction. Statistical methods are employed in order to establish a comparison between the different attacks.
Different ancient mortar samples of Pamplona's San Cernin church have been analyzed to characterize their binder and aggregate fractions. A complete characterization has been carried out including chemical (rapid approximate analysis, soluble salts and trace elements, using traditional chemical procedures, ionic chromatography and spectrophotometry techniques), mineralogical-petrographic (structural characterization and X-ray diffraction) and thermal studies (simultaneous differential thermal and thermogravimetric analysis). These studies have permitted to establish that a type of lime mortar with silica aggregate was employed in the building of the tower. Three different classes of this type of mortar and their approximate original composition have been determined. Recommendations about the employment of new materials in a possible restoration are given.
A thorough understanding of spatial and temporal emission and immission patterns of air pollutants in urban areas is challenged by the low number of air-quality monitoring stations available. Plants are promising low-cost biomonitoring tools. However, source identification of the trace metals incorporated in plant tissues (i.e., natural vs anthropogenic) and the identification of the best plant to use remain fundamental challenges. To this end, Nerium oleander L. collected in the city of Zaragoza (NE Spain) has been investigated as a biomonitoring tool for assessing the spatial immission patterns of airborne metals (Pb, Cu, Cr, Ni, Ce, and Zn). N. oleander leaves were sampled at 118 locations across the city, including the city center, industrial hotspots, ring-roads, and outskirts. Metal concentrations were generally higher within a 4 km radius around the city center. Calculated enrichment factors relative to upper continental crust suggest an anthropogenic origin for Cr, Cu, Ni, Pb, and Zn. Zinc isotopes showed significant variability that likely reflects different pollution sources. Plants closer to industrial hotspots showed heavier isotopic compositions (δZn up to +0.70‰), indicating significant contributions of fly ash particles, while those far away were isotopically light (up to -0.95‰), indicating significant contributions from exhaust emissions and flue gas. We suggest that this information is applied for improving the environmental and human risk assessment related to the exposure to air pollution in urban areas.
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