Comparison study of COD adsorption on bentonite-based nanocomposite materials in landfill leachate treatment: Characterization, Isotherms, Kinetics and Regeneration

The COD removal from landfill leachate using bentonite-based nanocomposites prepared using different modifiers has been investigated. Different techniques including FE-SEM, XRD, FTIR, TGA and Zeta potential have been utilized for characterization of nanocomposites (NCs). The independent variables includingNCs dose, pH and contact time are studied for COD removal efficiency. The optimal values are obtained to be a NCs dose of 40 g/L, pH of 3.00, and a contact time of 20 min for maximized COD removal efficiencies of 67.90, 71.30 and 52.00% using Arg/CTS-BEN, H/CTS-BEN and CTS -BEN NCs, respectively. Kinetics studies fitted well with the pseudo-second order model with rate constants of 25.64, 28.65 and 25.00 mg/g by H/CTS-BEN, Arg/CTS-BEN and CTS-BEN NCs, respectively. The adsorption of the COD is well described by Langmuir equations (R2 0.99). Results show that the synthesized NCs is promising and efficient in purifying landfill leachate.