Preparation and Characterization of Activated Carbon from Chestnut Shell and its Adsorption Characteristics for Lead

Abstract

Activated carbons were prepared from chestnut shell by phosphoric acid activation and the prepared activated carbons were used to remove lead(II) from aqueous solutions. The effects of impregnation ratio (IR) and activation temperature on activated carbon production were investigated. The produced activated carbons were characterized by N₂ adsorption, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The highest surface area (1611 m²/g) and total pore volume (0.7819 cm³/g) were obtained at a carbonization temperature of 500°C with an impregnation ratio of 3/1. The resulting activated carbon was used for removal of lead(II) from aqueous solution. The effects of temperature, contact time, and adsorbent dosage were investigated. The adsorption isotherm studies were carried out and the obtained data were analyzed by the Langmuir, Freundlich, and Temkin equations. The rate of adsorption was found to conform to the pseudo-second-order kinetic model. The Langmuir isotherm equation showed better fit for all temperatures and the maximum adsorption capacities of lead(II) was obtained as 138.88 mg/g at 45°C.

Keywords:

• activated carbon
• adsorption
• characterization
• chestnut shell
• lead