Removal of chloridazon from water by kerolite/stevensite and bentonite: a comparative study

Abstract

The adsorption of chloridazon (5-amino-4-chloro-2-phenylpyridazin-3(2H)-one) on a new type of material formed by kerolite/stevensite bearing lithofacies and on a bentonite, desiccated at 110°C from aqueous solution at 25°C has been studied by using batch experiments. In addition, column experiments were carried out with these samples using aqueous solutions of chloridazon at a concentration (C) of 45Â10 À4 cmol dm À3 . The experimental data points have been ®tted to the Langmuir equation to calculate the adsorption capacities (X m ). Values for X m ranged from 0.072 cmol kg À1 for bentonite up to 1.30 cmol kg À1 for kerolite. The removal ef®ciency, R, ranged from 17.1% for bentonite up to 85.1% for kerolite. The batch experiments show that the kerolite is more effective than bentonite in adsorbing chloridazon. The column experiments show that kerolite might be reasonably used in removing chloridazon, the data indicating that a readily available and inexpensive Spanish kerolite can be employed as a ®lter for contaminated waters with chloridazon, so controlling its release to the environment.