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 birnessite), 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.

Mineral Composition and Structural Characterization of the Clinoptilolite Powders Obtained from Zeolite-Rich Tuffs

“…The thermal behavior of the clinoptilolite-rich tuff from the Ukrainian deposit correlates quite well when compared to the previous study of the zeolitic tuff from the same source [50]. Chmielewská et al [64] proved that the Slovakian clinoptilolite-rich tuff from the same deposit as the studied Slovakian sample begins to undergo a structural phase transition at the temperature around 900 • C.…”

Kinetic and Isotherm Studies for Cu2+ and Cs+ Uptake with Mono- and Bimetallic FeO(OH)-MnOx-Clinoptilolite

“…The physicochemical specification of the inland clinoptilolite examined in this study, including structure and the surface morphology, is published in the literature [33]. The clinoptilolite used in this research comes from a long-term mined surface deposit near Nižný Hrabovec, from the region of East Slovak neovulcanites.…”

“…The clinoptilolite used in this research comes from a long-term mined surface deposit near Nižný Hrabovec, from the region of East Slovak neovulcanites. The mineralogical composition of the Slovak zeolite rock, as referred elsewhere [33][34][35], is the following: clinoptilolite 70%-80%, volcanic glass 15%-20%, feldspar 7%-10%, cristobalite 2%-4% and alfa-quartz 2%-3%. The MnOx-clinoptilolite, obtained in the form of crushed and sifted rock with an initial grain size ranging from 0.2% to 1.0 mm, was prepared following the procedure outlined in reference [33].…”

Role of Exopolysaccharides of Pseudomonas in Heavy Metal Removal and Other Remediation Strategies

“…The chemical leaching of soils and sediments by applying strong inorganic and organic acids and persistent synthetic chelating agents (e.g., ethylenediaminetetraacetic acid or its derivatives) to solubilize contaminants has also been successfully tested for heavy metal removal [ 7 ]. Reactive solid inorganic and biological substances, as well as materials with active surfaces (e.g., zero-valent iron, ferric oxides and oxohydroxides, nanomaterials, zeolite, biological waste) have been studied as potential components of permeable treatment barriers to restrict the movement of the contaminant in the environment [ 8 , 9 , 10 , 11 ]. However, in some cases, unpredictable effects regarding the toxicity and mobility of generated species can be expected since these interactions are usually non-specific.…”