Abstract

PEREZ, N.; DELGADO, L.  and  GONZALEZ, J.. Removal of Ni and V from aqueous solutions by lignins subjected to oxidative treatment with KMnO₄. Lat. Am. appl. res. [online]. 2012, vol.42, n.3, pp.223-228. ISSN 0327-0793.

Lignins were precipitated from Kraft black liquor to different acidic conditions; subsequently were subjected to oxidative treatment with KMnO₄. The oxidized material was characterized using IR spectroscopy for structural elucidation, and potentiometry in aqueous medium for determination of carboxylic groups. Among the trends, it found that the proportion of carboxylic groups in lignins increases with the oxidative treatment of the lignin. In addition with the IR were identified functional groups characteristic of lignin and showed also the changes caused by oxidative modification confirming the increase of oxidized groups when comparing the spectra of the different materials. Known the effects of oxidation on the lignins was evaluated adsorptive capacity of the oxidized lignin, showing that the oxidized lignin was able to adsorb up to 98% of Ni available initially, which corresponds to an increase in this ion sorption capacity of the double with respect to which only was precipitated. For its part, the lignin used to adsorb V decreased its adsorptive capacity, reaching only 19% of V fed. Based on this result was improved the experimental method of adsorption and the pH of process was controlled, thus it was obtained an increase of the adsorptive capacity of the material, reaching an adsorption of 91% of V fed. These results agree with the proposed mechanisms on how the metal ions studied in this work can be adsorbed.

Keywords : Lignin; Adsorption Heavy Metal; Oxidative Treatment.

        · text in English     · English ( pdf )