Enhancement of the adsorption of cadmium by modified orange peel with sodium hydroxide and ethyl alcohol

摘要

The aim of this work was to modify orange peel with sodium hydroxide and ethyl alcohol, and optimize the modified conditions and the adsorption parameters. The effects of various parameters including NaOH solution volume, NaOH solution concentration, ethyl alcohol volume, reaction time, reaction temperature, pH and Cd~(2+) solution initial concentration on the adsorption of Cd~(2+) were investigated detailedly. The NaOH solution volume, NaOH solution concentration and ethyl alcohol volume had strong effects on the adsorption of Cd~(2+) and their optimum values were determined as 25 mL, 24 g/L and 35 mL, respectively. The effects of reaction time and reaction temperature were not very significant and the appropriate values were determined as 10 min and 30°C, respectively. The pH and initial concentration of Cd~(2+) solution were had great influences on the removal efficiency of Cd~(2+). The removal efficiency of Cd~(2+) on modified orange peel had reached up to 98.4% when the initial concentration of Cd~(2+) solution was 200 mg/L and the pH of Cd~(2+) solution was 5.0, which was 4.6 times greater compared with that of pristine orange peel. The results showed this chemical modification of orange peel had enhanced effectively its adsorption capacity of cadmium.