Rice straw-derived activated carbons for the removal of carbofuran from an aqueous solution

Activated carbon was prepared from rice straw by carbonization and KOH activation, and was used as an adsorbent for the removal of a kind of pesticide, carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) from aqueous solution. The effects of the initial carbofuran concentration, contact time, temperature and pH, on its adsorption capacity and kinetics were studied using a batch method. The surface area and average pore diameter of the activated carbon were 1304.8 m2/g and 2.39 nm, respectively. The maximum adsorption capacity of the activated carbon (296.52 mg/g) for carbofuran was found to occur at 90 min, 30 °C and 200 mg/L initial carbofuran concentration with an adsorbent loading of 100 mg/L. Equilibrium adsorption isotherms were fitted better by the Langmuir model than the Freundlich and Temkin models. The adsorption follows a pseudo-second-order kinetics model.