Adsorptive removal of 2,4-dichlorophenol from aqueous solution by low-cost carbon from an agricultural solid waste: Coconut coir pith

Coconut coir pith, a solid waste generated in coir fibre industries, was carbonized and used as adsorbent for the removal of 2,4-dichlorophenol (2,4-DCP) from water. Varying parameters such as agitation time, 2,4-DCP concentration, adsorbent dose, pH, and temperature were investigated. Adsorption equilibrium reached at 60, 80, 100, and 120 min for 2,4-DCP concentrations of 10, 20, 30, and 40 mg L-1, respectively. Adsorption followed pseudo-second order kinetics. The adsorption equilibrium data moderately obeyed Langmuir and Freundlich isotherms. The adsorption capacity was found to be 19 mg g(-1) of carbon. Increase of temperature increased adsorption. Acidic pH was favorable for the adsorption of 2,4-DCP. Studies on pH effect and desorption show that both physisorption and chemisorption were involved in the adsorption process.