Removal of 2,4-Dichloro Phenoxy Acetic Acid by Silica Particles Obtained from the Siliceous Sand of Houeyogbe(Republic of Benin)

Abstract

In this study, silica sands from the commune of Houéyogbé were used to synthesize silica particles by the sol-gel method, using sodium silicate as the reaction precursor. Analysis by X-ray diffraction, infrared spectroscopy, and scanning electron microscopy revealed the formation of pure amorphous silica with spherical shapes. This material was used as an adsorbent to remove 2,4-dichlorophenoxyacetic acid, one of the pesticides most widely used by farmers in Benin. The use of pesticides is a major environmental problem due to their toxicity. Pesticides pollute soils, surface, and groundwater, and it is, therefore, important to find a way of mitigating or even eliminating their effects on the environment. Adsorption tests for this pollutant were carried out in batch mode. The adsorption study showed a maximum of over 90%. The kinetic study indicates that adsorption is effective from the first five (5) minutes and becomes established after one hour. The L-type adsorption isotherm shows that pesticide adsorption takes place by progressive saturation (monolayer).

Keywords

• benin
• silica
• sol-gel
• 2
• 4-d acid
• adsorption