Nanoporous manganese oxides as environmental protective materials—Effect of Ca and Mg on metals sorption

• Published in: Journal of hazardous materials Vol. 180; no. 1; pp. 234 - 240
• Main Authors: Pakarinen, Jouni, Koivula, Risto, Laatikainen, Markku, Laatikainen, Katri, Paatero, Erkki, Harjula, Risto
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.08.2010; Elsevier
• Subjects: Adsorption; Applied sciences; Cadmium; Calcium - chemistry; Chemical engineering; Conservation of Natural Resources; Copper; Diffusion; Exact sciences and technology; Ion exchange; Magnesium; Magnesium - chemistry; Manganese oxide; Manganese oxides; Materials selection; Metals - chemistry; Microscopy, Electron, Scanning; Molecular sieve; Nanocomposites; Nanomaterials; Nanostructure; Nanotechnology; OMS; Pollution; Spectroscopy, Fourier Transform Infrared; Uptakes; X-Ray Diffraction; OMS; Ion exchange; Diffusion; Manganese oxide; Molecular sieve; Sorption; Batchwise; Metal ion; Kinetics; Dynamic model; Modeling; Uptake
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2010.04.019

The selectivity of nanoporous manganese oxides for some alkali and transition metals over calcium and magnesium was studied. Two tunnel-structured oxides (OMS-1 and OMS-2) were synthesized by means of a hydrothermal route. Competitive uptake of metals and acid was studied using batch kinetic measurements at different metal ion concentrations. The experimental data were correlated with a dynamic model. The results show that the studied OMS materials selectively adsorb Cu, Ni and Cd in the presence of Ca and Mg. It was also found that the exchange rates were reasonably high due to the small particle dimensions. Both materials are stable in the studied conditions and their maximum Cu uptake capacity was 0.9–1.3 mmol/g. The results indicate that both materials have potential for environmental applications involving the uptake of harmful metal ions.