Kinetic, Equilibrium and Thermodynamic Study of Chlorantraniliprole Removal from Water using Zr-UiO-66

UiO-66, a Zr-based metal organic framework exhibited a BET surface area (SBET) of 843.41 m2 g–1, with pore size and total pore volume 1.71 nm and 0.52 cm3 g–1, respectively and showed a characteristic Type I N2 adsorption-desorption isotherm. The material had an average particle size of 958 nm and a negative zeta potential i.e. -30.12 mV at pH 7, indicating the negative polarity, facilitating π–π interactions and weak hydrophobic interactions with chlorantraniliprole. The adsorption of chlorantraniliprole on UiO-66 followed a favourable monolayer mechanism as described by the Langmuir isotherm and the process was endothermic and chemisorptive, consistent with the pseudo-second-order kinetic model. Thermodynamic parameters (ΔHº = 20.50 kJ mol–1; ΔSº = 78.9 kJ mol–1 K–1) and negative ΔGº values (-0.77 to -1.66 kJ mol–1) indicated spontaneous adsorption. Under optimised conditions, UiO-66 achieved 86.5% removal of chlorantraniliprole (20 mg L–1). The MOF maintained performance over four regeneration cycles using DMF washing and heating (80 ºC).