Adsorption Thermodynamics and Kinetics of Mancozeb onto Poly- o -toluidine Th(IV) Phosphate — a Nano-composite Cation-exchanger — and its Application as a Mancozeb-sensitive Membrane Electrode

Abstract

A newly-synthesized poly-o-toluidine Th(IV) phosphate nano-composite cation-exchanger was employed as an adsorbent to study the adsorption thermodynamics and kinetics of Mancozeb from aqueous media. Some parameters such as the Freundlich constants, the thermodynamic equilibrium constant (K₀), the standard free energy change (ΔG⁰), the standard enthalpy change (ΔH⁰) and the standard entropy change (ΔS⁰) were determined. Thermodynamic analysis revealed that the adsorption of Mancozeb onto poly-o-toluidine Th(IV) phosphate was exothermic, spontaneous and decreased as the temperature was increased from 25 °C to 45 °C. A pesticide-sensitive membrane electrode was fabricated using poly-o-toluidine Th(IV) phosphate as an electro-active composite material. Its sensitivity towards Mancozeb was monitored.