Hydrotalcites and organo-hydrotalcites as sorbents for removing pesticides from water.

This paper reports on the adsorption of different organic pesticides by hydrotalcite, hydrotalcite heated to 500 degrees C and organo-hydrotalcite in aqueous medium by employing adsorption isotherms, and using X-ray diffraction and infrared spectroscopy techniques. The results suggest that the adsorption capacity of the different materials depends on their nature as well as on the structure, polarity and hydrophobic or anionic nature of the pesticides. The results also show that hydrotalcite, both natural and after calcination at 500 degrees C, is not a good sorbent of hydrophobic pesticides. The data demonstrated that both types of hydrotalcite, however, are very good sorbents of glyphosphate. Furthermore, the organo-hydrotalcites may be as good sorbents as organo-montmorillonites for hydrophobic pesticides.