Raman spectroscopy speciation of natural and anthropogenic solid phases in river and estuarine sediments with appreciable amount of clay and organic matter
✍ Scribed by U. Villanueva; J. C. Raposo; K. Castro; A. de Diego; G. Arana; J. M. Madariaga
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 168 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0377-0486
- DOI
- 10.1002/jrs.1963
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✦ Synopsis
Abstract
A new methodology is proposed in order to perform direct Raman measurements in sediments with high content in clay and organic matter with a reduced pre‐treatment.
Following this method, different compounds were found within the samples, some of them were assigned as natural compounds (clay, iron oxide, pyrite, aragonite, calcite, silicates and quartz) and the others were included in the group that comes from the human activity (titanium oxide, phthalocyanine blue, phthalocyanine green, gypsum, calcium arsenate, lead oxide, zinc oxide, sodium sulfide and iron hydroxioxide).
The study of the presence of these polluting agents and their differentiation from the compounds that belong to the sediments as natural compounds is fundamental in order to understand the mobility/retention processes of the pollutants, and thus, their bioavailability. Also the speciation studies of solid phase downstream a wastewater treatment plant can be the basis to diagnose the adequate functioning of the facility.
This work shows the applicability of Raman spectroscopy to perform speciation studies in the solid phases of natural and anthropogenic compounds present in river and estuarine sediments with appreciable content in clay and organic matter. The differentiation between natural and anthropogenic compounds is of fundamental interest because the potential toxicity of a metal (i.e. arsenic) in a natural compound (i.e. arsenopyrite) is not the same as in a newly formed synthetic compound in the river system due to an anthropogenic input (i.e. calcium arsenate). This illustrates the importance of the analysis of solid phases present in sediments because most of the polluting agents can be found in a different molecular configuration than the natural one. Copyright © 2008 John Wiley & Sons, Ltd.