Actually water sources are constantly polluted by chemicals (including heavy metals), biologicals and others. Since a cellulose can be found in plants and is characterized as a high molecular weight, homopolymer and has hydroxyls that are out of surface, forming well-ordered structures, that in the less orderly regions, it allows these hydroxyl groups to perform hydrogen bonding with other molecules polars, affording absorb a large amount of water and other polar molecule. When reducing size of the fibers to a nanometer scale, it is called as nanocellulose, has a larger surface area when compared to the cellulose in original size. Nanocellulose (CNF) was obtained by the chemical route with NaBr, NaClO at pH 10, NaOH, cellulose and TEMPO catalyzer. The reaction occurs as the pH decreases, so when the pH keeps constant at 10 the reaction ends. CNF has high crystallinity, width between 2 and 8nm and potential zeta between -30 and -10mV and, mass loss starts at 195 celsius degrees with activation energy 40,9358 e 45,5978kJ/mol. Given these technical features, water contaminated with dissolved metals, such as magnesium, cobalt and mercury, were placed in contact with the CNF for 3h observing more 90 percent reduction of the concentration, besides, a small cobalt adsorption curve was plotted, by analyzing adsorption over 12h. Therefore, conclude that CNF can be used for adsorption of these metals.