Boron removal from water by adsorption onto activated carbon prepared from palm bark: Kinetic, isotherms, optimisation and breakthrough curves modeling

Abstract

The occurrence of boron in water and its inefficient removal are the key issue in desalination and water treatment. Adsorption by fixed-bed column is usually used to remove mineral and organic contaminants from the aqueous phase. The adsorption of the boron onto activated carbon, prepared from palm bark, is studied. Batch adsorption experiments are developed to determine the equilibrium time and the best isotherm model. The kinetic adsorption data can be described by the second-order equation. Among the adsorption isotherm models, Langmuir and Sips models give better fit of the equilibrium data. The calculated thermodynamic parameters show that the boron adsorption is exothermic in nature. The effects of inlet boron concentration, feed flow rate and weight of activated carbon on the fixed-bed adsorption are determined by two-level factorial experimental design. Breakthrough and saturation times are higher at high adsorbent weight and low flow rates. The increase of boron initial concentration decreases breakthrough and saturation times. The volume treated per gram of activated carbon is higher at lower initial concentrations and at higher adsorbent weight. Compared to other models, the Yan model fits better the experimental data of the breakthrough curves with R2 of 0.993.