Removal of chloridazon by natural and ammonium kerolite samples

The adsorption of chloridazon (5-amino-4-chloro-2-phenylpyridazin-3(2H)-one) on natural and ammonium kerolite samples from aqueous solution at 10, 25 and 40 8C has been studied by using batch experiments. The experimental data points were fitted to the Langmuir equation in order to calculate the adsorption capacities (Xm) of the samples; two straight lines were obtained, which indicates that the adsorption process takes place in two different stages. Values for Xm1 (first stage) ranged from 1.1 10 2 mol kg 1 for natural kerolite at 40 8C up to 5.1 10 2 mol kg 1 for ammonium kerolite at 10 8C and the values for Xm2 (second stage) ranged from 9.1 10 2 mol kg 1 for natural kerolite at 40 8C up to 14 10 2 mol kg 1 for natural kerolite at 10 8C. The adsorption experiments showed on the one hand, that the ammonium kerolite is more effective than natural kerolite to adsorb chloridazon in the range of temperature studied and on the other hand, that the lower temperature, the more effective the adsorption of chloridazon on the adsorbents studied.