Adsorption of bromoxynil by modified bentonite: influence of pH and temperature

Abstract

This study investigates the adsorption behavior of bromoxynil under various pH and temperature conditions. Organo-bentonite complexes were prepared and used as adsorbents for bromoxynil. The concentrations of bromoxynil in equilibrium solution were determined by HPLC. Results showed that bromoxynil was best adsorbed by bentonite surfaces modified with NCP or HDTBP at various loadings, and adsorption was further enhanced by lowering the pH and/or optimizing the temperature of the adsorption reaction. Release of bromoxynil from NCP-, or HDTBP-bentonite- bromoxynil was slower than from raw bentonite-bromoxynil. Organo-bentonite complexes may be suitable materials for designing controlled release formulations of herbicides.