Enhancing The Adsorption Capacity of Commercial Kaolin for Efficient Removal of Lead Ions from Aqueous Solutions

Abstract

The sorption of lead ions (Pb⁺²) from aqueous solutions using commercial kaolin (KC) was investigated. The effects of various factors such as dosage, different pH media, different concentration, and temperature on the adsorption process were investigated. The Langmuir model was determined to fit the Pb⁺²sorption model on KC. Langmuir model parameters q_m, K_L, and R², were found to be 31.2, 0.0014, and 0.9908 mg.g^-1 respectively. The q_max of the Pb⁺² on KC was 31.2 mg.g^-1 at pH 5.7, 500 mg of KC, and 25^?C. Free energy (?G), enthalpy (?H), and entropy (?S) were calculated to understand the nature of the sorption  process. Negative ?G, negative ?H, and positive ?S were found to indicate the adsorption process is non-spontaneous, exothermic, and random, respectively. A pseudo-second-order (PSO) model was followed for the adsorption process. The percentage extractions (%ER) found ranged from 102.5- 90.8 % for stimulation mineral water and tap water samples. This research provides valuable insights for the development of efficient and sustainable methods for water treatment and environmental remediation.