Preparation and evaluation of cattail fiber-based activated carbon for 2,4-dichlorophenol and 2,4,6-trichlorophenol removal

To remove 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solutions, an activated carbon adsorbent was fabricated by phosphoric acid activation of a cattail (Typha orientalis) fiber precursor. According to the BET surface area and the infrared spectrum, the cattail fiber activated carbon (CFAC) has a porous structure with a large surface area of 890.27 m2/g and many functional groups (hydroxyl group, lactone group, carboxyl group, etc.). The effects of experimental parameters such as initial concentration, contact time, solution pH and temperature on the adsorption were investigated. Acidic pH was more favorable for the adsorption process. The adsorption kinetics was best represented by the pseudo-second-order kinetic model. The mechanism of the adsorption process was determined from the intra-particle diffusion model. The adsorption isotherm models fitted the data in the order: Freundlich > Langmuir > Tempkin isotherms. Thermodynamic study showed that the adsorption was a non-spontaneous, exothermic process.