Adsorption of methylene blue from aqueous solution onto NaOH-modified rejected tea

In this work, the removal of a basic dye, methylene blue (MB) from aqueous solution using NaOH-modified rejected tea (N-RT) was investigated. Equilibrium adsorption and kinetics were studied. The results confirmed that the adsorption isotherm data fitted well to Langmuir isotherm with monolayer adsorption capacity of 242.11 mg/g. The kinetics of MB adsorption process was found to follow pseudo-second-order rate expression. The results suggested that the N-RT would be an excellent alternative for the removal of MB by adsorption process.