Mineralogical and hydrogeologic properties of a partially unconsolidated Pleistocene limestone in the east central Yucatán: implications for the development of subsurface flow constructed wetlands (SFCWs) in the region
- Autores: Mark P. S. Krekeler, Clancy Calkins, Olaf Borkiewicz
- Localización: Carbonates and Evaporites, ISSN 0891-2556, Vol. 25, Nº. 1, 2010, págs. 77-86
- Idioma: inglés
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Resumen
A partially unconsolidated Pleistocene limestone from a roadside quarry near kilometer 175 on route 307 in the eastern Yucatán was investigated to assess suitability for use in subsurface flow constructed wetlands (SFCWs) in the region. Powder X-ray diffraction investigation of bulk samples indicates that the mineralogy consists of calcite with minor amounts of quartz. Clay-sized insoluble materials in the limestone constitute approximately 2-8 wt% of samples. Powder X-ray diffraction combined with transmission electron microscopy indicates that insoluble materials are dominantly Ca-montmorillonite with trace amounts of kaolinite and minor amounts of amorphous aluminum-silicon oxides. Bulk properties are generally appropriate for use as media with hydraulic conductivity values (K) varying from approximately 0.0001-0.0393 cm/s. Uniformity coefficients (Cu) vary from 3 to 5.35. Owing to the partially unconsolidated nature of the limestone, it is possible to modify the materials to desired parameters for needs of a given SFCW. The occurrence of Ca-montmorillonite and Al-Si oxides in the material has some environmental advantages in being able to absorb a wider range of pollutants over current aragonite and calcite-based aggregate. The aggregate source is in a geographically strategic location to serve the expanding development of tourism infrastructure. The limestone material is an environmentally sound and economically advantageous target material for use in SFCWs because transportation costs and crushing costs are minimized and mining would be from an already disturbed portion of the landscape.
