Adsorption of 2,4,6-trichlorophenol from aqueous solution onto activated carbon derived from loosestrife

An activated carbon was prepared from the stalk of the scrap aquatic plant loosestrife, by H3PO4 activation and then was evaluated for its ability to adsorb 2,4,6-trichlorophenol (TCP). The effects of solution pH, agitation time, TCP initial concentration, and temperature on TCP adsorption were investigated. The equilibrium adsorption data of TCP on activated carbon were analyzed by Langmuir, Freundlich and Temkin isotherm models. The Temkin model gave the best correlation with the experimental data. The adsorption was found to follow the pseudo-second-order kinetics. The intraparticle diffusion model was used to determine the mechanism of the adsorption process. Thermodynamic parameters such as standard enthalpy (ΔHo), standard entropy (ΔSo), and standard free energy (ΔGo) were obtained. Adsorption of TCP is exothermic with ΔHo at −12.87 kJ/mol.

Research highlights
► An inexpensive activated carbon was prepared from the renewable source loosestrife.
► The inner structure of loosestrife can be an advantage to produce quality adsorbent.
► The LAC is a high quality adsorbent with surface area as high as 1255.75 m2/g.
► The adsorption potential of 2,4,6-TCP adsorbed on LAC was favorable.