In view of the high risk that metals pose to living beings’lives, it is of great importance that their emission to the environ-ment is greatly reduced or, if possible, eliminated, and also thata rigorous control over their emission is accomplished. To do so,many techniques have been proposed to remediate wastewaters
[9–21]. One of the main techniques is the use of adsorbent materials
like zeolites, silicas, polymers, cellulose, industrial/agricultural
wastes, activated carbon and clays among others [13,15–22]. Nevertheless,
some of these materials in their bare forms do not
present extraordinary adsorptive capacity and, thus, require an
organofunctionalization step, prior to their application as adsorbents
[22–25]. In this step, generally a complexing/chelating
molecule (“ligand”) is coupled to their surfaces, which enables them
to sequester metal ions from solution [23]. Due to the presence
of non-bonded electrons in such molecules, they may coordinate
to the metal cations forming a stable ligand–cation covalent bond
[26], allowing the removal of metal species. In spite of the current
great success acquired by organofunctionalized materials, they still
present a serious drawback in detriment of their wide application,
which is the use of costly high purity reagents and solvents involved
in their manufacturing. Furthermore, the synthesis and functionalization
of such materials are usually associated to the generation
of toxic residues