Adsorption Of Arsenic(v) Into Modified Lamellar Kenyaite

摘要

The synthetic Kenyaite sample was used for organofunctionalization process with N-propyldiethyle-netrimethoxysilane and bis[3-(triethoxysilyl)propyl]tetrasulfide. The resulted materials were submitted to process of adsorption with arsenic solution at pH 2.0 and 298 ±1 K. The adsorption isotherms were adjusted using a modified Langmuir equation with regression non-linear; the net thermal effects obtained from calorimetric titration measurements were adjusted to a modified Langmuir equation. The adsorption process was exothermic (△_(int)H = -4.08 to -5.94kJ mol~(-1)) accompanied by increase in entropy (△_(int)S = 41.29 - 62.09J K~(-1) mol~(-1)) and Gibbs energy (△_(int)G = -22.33 to -24.45 kJ mol~(-1)). The energetic effect caused by metal cation adsorption was determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant.