Kinetic experiments: Kinetic experiments were performed to determine the experimental
adsorption rates. In these experiments, the lead and chromium ions concentration in the bulk
solution was decreased over time until it reached the state of equilibrium. The experiments on the rate of adsorption were run for a total period of 3 h. A specific agitation speed was used with 1 g of clay sample added to 50 mL of lead and chromium ions solution separately having a specific initial metal ions solution concentration in bottles placed on a thermostat-controlled shaker.
After starting the shaking, a sample of one bottle was taken at different time intervals till the end of 3 h. Filtration of the mixture was done and the absorbance was measured by atomic absorption spectroscopy. Later on, the absorbance was converted to concentration.