Adsorption of Chlorendic Acid onto Hydrophilic Fumed Titanium Dioxide (P25)

Abstract

The adsorption behavior of chlorendic acid (1, 4, 5, 6, 7, 7-hexachlorobicyclo-(2, 2, 1) -hept-5-ene-2, 3-dicarboxylic acid) onto hydrophilic fumed TiO2 (P-25, Degussa) in aqueous suspension was investigated. Results indicate that chlorendic acid adsorbed strongly in short times (2-5 mins) onto TiO2. Adsorption data is consistent with Langmuir-Hinshelwood isotherm model for monolayer adsorption and the shape of the isotherm indicates second order behavior. Calculated adsorption constant K, and maximum adsorbable quantity at 20oC were obtained as (0.12 ± 0.03) l/mg and (4.4 ± 0.2) mg/g TiO2 respectively. Adsorption of chlorendic acid in water onto TiO2 is exothermic.