Removal of Parathion from Aqueous Media Throughp-tert-Butylcalix[4]arene Based Modified Silica

Sibghatullah Memon; Najma Memon; Shahabuddin Memon

doi:10.21743/

Authors

Sibghatullah Memon National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan Author
Najma Memon National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan Author
Shahabuddin Memon National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan Author

DOI:

https://doi.org/10.21743/

Keywords:

Calixarene; Parathion; Adsorption isotherms; Kinetics; Thermodynamics

Abstract

This study explores, adsorption efficiency of p-tert-butylcalix[4]arene based modified silica to remove parathion from aqueous environment. The adsorption parameters, i.e. pH, concentration of pesticide solution, contact time and adsorbent dosage were optimized, as 10, 1 mg L^-1, 40 min and 0.04 g, respectively. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models were used to evaluate the adsorption mechanism. Adsorption constants values of these models suggest that the adsorption of parathion is favorable and were found to be best fit with Freundlich isotherm. From the kinetic study it can be predicted that adsorption of parathion follows Ho and McKay model (pseudo-second order). Thermodynamic parameters, enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) have also been evaluated and were found as -132.25, 0.45, -4.14 Jmol-1, respectively.