Adsorption of Cesium, Cobalt, and Lead onto a Synthetic Nano Manganese Oxide: Behavior and Mechanism

Abstract

Synthesis parameters of nano manganese oxide (NMO) were tuned in order to maximize Cs and Co sorption efficiencies. The prepared oxide was characterized using various techniques including x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), SEM, and surface area analyzer. The sorption characteristics with respect to uptake of Cs, Co, and Pb were evaluated. An α − phase nano manganese oxide with a surface area of 165 m 2 g −1 was synthesized. Maximum adsorption capacities were 230 mg g −1 for Pb 2+ , 73 mg g −1 for Cs + , and 26 mg g −1 for Co 2+ . The intraparticle diffusion was the rate-limiting step in the case of Pb 2+ , whereas both intra-particle diffusion and film diffusion contribute to the rate-determining step in the adsorption process in the case of Cs + and Co 2+ . FT-IR analyses reveled that Cs + and Co 2+ coordinated to vacancy sites of NMO as inner-sphere complexes, while Pb 2+ formed bidentate corner-sharing complexes. NMO had high affinity for Pb 2+ but was also effective for sorption of Cs + and Co 2+ over a wide pH range, even in the presence of Na + . HCl (0.5 mol L −1 ) solution could regenerate the adsorbent successfully, and the NMO could be efficiently reused with lower production of residues. Thus, the prepared NMO can be efficiently used in wastewater treatment in terms of high adsorption capacity, easy availability, and low cost.

Efficient removal of Pb(ii) ions using manganese oxides: the role of crystal structure

“…Kozlova et al 17 prepared complex manganese oxides with different sizes of structural tunnels, and concluded that the tunnel size was the determining factor for the sorption of heavy metal cations. In addition, Korshin et al 18 and Abdullah et al 19 found that heavy metal ions could be complexed at different adsorption sites on birnessite and a-MnO 2 using EXAFS spectroscopy. Wang et al 10 studied the adsorption mechanisms of Pb(II) onto varied birnessite type MnO 2 and found that the adsorption capacities were largely controlled by the Mn average oxidation states and type of sorption sites on the MnO 2 surface.…”

Effective adsorption and collection of cesium from aqueous solution using graphene oxide grown on porous alumina

“…This decreases the binding energies of the whole electronic state of C. Spectral analysis of the peak intensity ratio between C 1s and Cs 3d 5=2 reveals that the maximum adsorption capacity of the GO=porous alumina film for Cs atoms in the CsCl solution is 650-850 mg g −1 , which is highly efficient compared with previous adsorbents such as organic molecules, nano structured oxides, and zeolites. [31][32][33] …”

Evaluation of Factors Affecting Chemical Extraction of Co Ions from Contaminated Soil

“…Fe-and Mn-oxides and hydroxides have been generally recognized as the major substrates for Co ions in the soil [34]. High affinities of such minerals toward Co ions were also revealed in the studies of Co sorption by Fe-and Mn-oxides [35][36][37], as well as by geochemical modeling of Co speciation in different soil samples [38]. The amounts of Co found in F2 phase of the sequential extraction correspond to the fraction associated with carbonates, as well as the fraction chemisorbed on the surface of soil components.…”