Preparation and use of solvent impregnated clay containing amine for the removal of copper ion

摘要

In this study, montmorilloniteK-10 (Mt) clay was used to adsorb a heavy metal ion, copper (Cu2+). This clay was also modified (Mt-TOA) by incorporating amine group of tri-n-octylamine (TOA), a tertiary amine. Experiments were performed in batch mode to determine equilibrium and kinetics of copper adsorption. Several parameters like adsorbent dose (0.1-0.6 g), initial copper concentration (20-80 mg/L), temperature (298 K to 333 K) and time of contact (t, 0 to 120 min) were varied, and their effect on the adsorption capacity of both the adsorbents were determined. Kinetic equilibrium reached after 80 min time of adsorption with 65.73% and 71.96% removal using Mt (0.2 g) and Mt-TOA (0.2 g). The Langmuir and pseudo second order models fitted the equilibrium and kinetic data, respectively. The change in enthalpy and entropy were also estimated (Delta H degrees = 16.44 kJ/mol and Delta S degrees = -73.23 J/mol/K for Mt; Delta H degrees = 9.26 kJ/mol and Delta S degrees = -45.92 J/mol/K for Mt-TOA) by using Gibbs' thermodynamic model.