Sorption of atrazine, propazine, deethylatrazine, deisopropylatrazine and hydroxyatrazine onto organovermiculite

The interaction of atrazine (AT), propazine (PROP), deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HAT) was studied with the clay mineral vermiculite saturated with K+ (VTK), and with the mineral modified by insertion of hexadecyltrimethyl-ammonium (HDTMA-VT) in the interlayer of VTK. The crude VTK exhibited negligible interaction with AT, PROP and DEA, moderate interaction with DIA and strong interaction with HAT. For the HDTMA-VT materials, removal percentages from aqueous medium for initial concentrations between 0.05 and 1.00 mg L-1 were 56 to 63% for AT, 43 to 45% for DEA, 12 to 19% for HAT and 77 to 78% for PROP. Sorption of AT, DEA and PROP onto HDTMA-VT was significantly enhanced in comparison to VTK. Ionic strength and pH had no significant influence on the sorption process. Desorption of all compounds from HDTMA-VT after 24 h of contact time was between 20 and 30% of the amount initially adsorbed.