Study of mono‐ and bimetallic fe and mn oxide‐supported clinoptilolite for improved pb(Ii) removal

Abstract

A cost‐effective, iron‐ and manganese‐oxide‐supported clinoptilolite‐based rock was prepared. Based on its nanoporous structure, it worked as a nanoreactor, thereby providing enhanced functionalities. The mono‐ and bimetallic Fe‐ and Mn‐oxide‐supported clinoptilolite was thoroughly characterized with thermoanalytical FT‐IR, XRD, SEM, and XPS spectroscopy. All the spectral procedures that were used confirmed the occurrence of a new MnO2 phase (predominantly bir-nessite), including mostly amorphous iron oxi(hydr)oxide (FeO(OH)) species on the surface of the above‐synthesized adsorbents. The synthesized products validated a considerably higher adsorption capacity toward Pb(II) pollutants compared to the natural clinoptilolite. The following order of a(max) toward Pb(II) was found: MnOx‐zeolite (202.1 mg/g) > FeO(OH)‐MnOx‐zeolite (101.3 mg/g) > FeO(OH)‐zeolite (80 mg/g) > natural zeolite (54.9 mg/g). The adsorption equilibrium data were analyzed by the two‐parameter empirical isotherm models Langmuir, Freundlich, and BET as well as the three‐parameter Redlich–Peterson isotherm.