Removal of atrazine from aqueous solution by natural and activated bentonite

To evaluate the potential use of bentonite in removing atrazine [2-chloro-4-ethylamino-6-isopropilamino-1,3,5-triazine] from water, the adsorption of atrazine on bentonite desiccated at 383 K untreated, and acid-treated with H2SO4 solutions over a concentration range between 0.25 x 10(3) cmol L-1 and 1.00 x 10(3) cmol L-1, from aqueous solution at 303 K has been studied by using batch experiments, In addition, column experiments were carried out with the bentonite samples treated with the 1.00 x 10(3) cmol L-1 H2SO4 [B-A (1.00)] using two aqueous atrazine solutions at C = 5.91 mg L-1 and C = 9.78 mg L-1 concentrations. The experimental data points have been fitted to the Langmuir equation to calculate the adsorption capacities (X-m). Values for X-m ranged from 0.07 g kg(-1) for the untreated bentonite up to 13.4 g kg(-1) for the [B-A (1.00)] samples. The removal efficiency (R) ranged from 2.71% for the B-N up to 83.5% for B-A (1.00), The batch experiments show that the acid-treated bentonite is more effective than the natural bentonite in relation to the adsorption of atrazine, The column experiments show that the B-A (1.00) sample might be reasonably used in removing atrazine, the column efficiency increasing from 47.5% for the C = 9.78 mg L-1 aqueous solution of atrazine up to 63.4% for the C = 5.91 mg L-1 one.