Thermodynamics of carbofuran adsorption on pyrite

Thermodynamic parameters of carbofuran adsorption on pyrite were determined from experimental data. In order to minimize the dissolution of pyrite as well the degradation of carbofuran, all experiments were restricted to (15 to 20) min. The maximum adsorption capacity of carbofuran varied with both pH and temperature in the order: ΓcarbmaxpH1.77>ΓcarbmaxpH2.70>ΓcarbmaxpH4.01. The Dubinin–Radushkevick (D–R) model was used to assess the degree of site heterogeneity. The interactions between carbofuran and surface sites can largely be ascribed to specific chemical interactions.

► We examined the carbofuran adsorption by pyrite.
► Carbofuran optimally adsorbed on pyrite around pH ∼1.70.
► Pyrite sites showed homogeneity for carbofuran-surface interactions.
► Carbofuran showed a slow degradation on pyrite sites when exposed to prolong periods.