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.