Modeling of linear alkyl benzene sulphonic acid removal from aqueous solution with fixed bed adsorption column: Thomas and Yoon-Nelson methods

BACKGROUND In Turkey, which is one of the world's top walnut producers, the volume of waste shell has increased in recent years as a result of escalating consumption. Globally, including in Turkey, cleaning products are the leading pollutants entering the aquatic environment. This study aimed to address both issues, by investigating the removal of Linear Alkyl Benzene Sulphonic Acid synthetic solution through a fixed-bed adsorption column system embedded with the composite of a polyaniline-supported activated walnut shell. RESULTS Linear Alkyl Benzene Sulfonic Acid removal efficiency was evaluated in terms of detergent and chemical oxygen demand (COD) parameters. Column performance increased with low flow rate, increased bed height and high inlet concentration. Optimum conditions were determined as 7.5 cm bed height, 10 mL min(-1) flow rate, and 30 mg L-1 inlet solution concentration. Thomas and Yoon-Nelson models were applied to experimental data to estimate the column adsorption behavior. The Yoon-Nelson model (R-2 > 0.9) seemed fit to explain the adsorption column behavior. To understand the reuse capacity of the adsorbent a regeneration study was carried out, showing that the maximum adsorption capacity of the adsorbent (q(total)) decreased from 216 mg g(-1) before regeneration to 6.4 mg g(-1) after the third regeneration cycle. CONCLUSION This adsorbent has a high potential for detergent and COD adsorption from anionic aqueous solutions, and would be a good alternative for a pretreatment step. (c) 2022 Society of Chemical Industry (SCI).