This work presents an evaluation of iron and cadmium adsorption in sediment of the Furnas Hydroelectric
Plant Reservatory located in Alfenas, Minas Gerais (Brazil). The metal determination was done employing
a flow injection analysis (FIA) with an on-line filtering system. As detection techniques, flame atomic
absorption spectrometry (FAAS) for iron and thermospray flame furnace atomic absorption spectrometry
(TS-FF-AAS) for cadmium determinations were used. The developed methodology presented good limits
of detection, being 190 g L−1 for iron and 1.36 g L−1 for cadmium, and high sampling frequency for
both metals 144 and 60 readings h−1 for iron and cadmium, respectively. Both metals obey the Langmuir
model, with maximum adsorptive capacity of 0·169 mg g−1 for iron and 7·991 mg g−1 for cadmium. For
iron, a pseudo-first-order kinetic model was obtained with a theoretical Qe = 9·8355 mg g−1 (experimental
Qe = 9·5432 mg g−1), while for cadmium, a pseudo-second-order kinetic model was obtained, with a
theoretical Qe = 0.3123 mg g−1 (experimental Qe = 0·3052 mg g−1).