Potential use of modified hydrotalcites as adsorbent of Bentazon and Metazachlor

The objective of the present research was to investigate the adsorption of pesticides on hydrotalcites modified with tetradecanedioate anions (TDD) or with humic acids (HA). In this study has been compared the pesticide adsorption on two different organohydrotalcites (OHTs) with tetradecanedioate anions in the interlayer (MA-TDD, MAF-TDD) and on other with humic acid (MAF-HA), all obtained by the coprecipitation method. Additionally, a calcined hydrotalcite has been used to adsorb Bentazon. X-ray diffraction of adsorption products on the organohydrotalcites MA-TDD and MAF-TDD showed the introduction of TDD anion and Metazachlor in the interlayer. Kinetic tests showed that the adsorption of pesticides Bentazon and Metazachlor involves intraparticle diffusion. Based on the results of regeneration tests, calcined hydrotalcite is an effective adsorbent for the removal of Bentazon from contaminated water. The results of regeneration tests suggest the possibility of using organohydrotalcites MA-TDD, MAF-TDD and MAF-HA to remove Metazachlor from contaminated water.