Examinando por Materia "Artisanal gold mining"

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    Especiación de mercurio en sedimentos de la Mojana sucreña mediante desorción térmica programada.
    (2020-01-28) Madera Posada, María Carolina; Marrugo Negrete, José Luis; Urango Cárdenas, Iván David
    The Mojana region is one of the most important ecosystems in Colombia, however, several authors have demonstrated the degree of mercury contamination in their aquatic systems (Pinedo, Marrugo, & Díez, 2015). Being the sediment analysis one of the most used pollution indicators today, because its characterization and speciation can help to understand conditions such as the presence, bioavailability mobility and toxicity of the metal (Ana Teresa Reis, Davidson, Vale, & Pereira, 2016). Therefore, the present investigation describes the application of thermal desorption as a technique for direct speciation of low-cost and rapid mercury; therefore, 3 sediment samples from the Mojana region were analyzed, using a direct mercury analyzer DMA80. The temperatures used were 100, 150, 200, 250, 300, 400, 450, 500, 600, 650 ° C. Sequential extraction was also performed using the BLOOM method, physicochemical parameters were evaluated. The results showed that the sediments in general have an acidic pH ranging between 3.32 and 5.08, it was also found that the% MO was 2.0, 2.77 and 1.05% for Quebradona, Encaramada and Caimanera swamp respectively, and the redox potential is of character reducer. The total concentrations of Hg for the different sampling points were: Quebradone (137.75 ng / gr); Perched (79.76 ng / gr) Caimanera Swamp (132.70 ng / gr), for thermodesorption it was obtained that about 90% of the mercury is linked to HgCl2.