Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4990190 | Separation and Purification Technology | 2017 | 11 Pages |
Abstract
The removal of heavy metal such as lead (Pb), cadmium (Cd), and copper (Cu) was assessed using magnesium oxide cores with silica coated nano-magnetite (MTM) prepared by a simple method using chemicals such as iron(II) sulfate heptahydrate (FeSO4·7H2O), magnesium (II) nitrate hexahydrate [Mg(NO3)2·6H2O], tetraethyl orthosilicate (TEOS), and urea. The MTM was characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and alternating gradient magnetometer (AGM) analyses. The isotherm, kinetic, and intra-particle diffusion studies indicated that the MTM had excellent removal capacities towards heavy metals (Pb, Cd, Cu) and the adsorption capacities were as high as 238 mg gâ1 (1.15 mmol gâ1) for Pb, 85.1 mg gâ1 (0.75 mmol gâ1) for Cd, and 33.5 mg gâ1 (0.5 mmol gâ1) for Cu. The intra-particle diffusion, FE-SEM, XPS, and XRD results indicated that the mechanism of heavy metal removal was mainly substitution, followed by precipitation. A leaching test revealed that MTM showed no leaching of Fe ions at pH > 2. This material is cheap, simple, and can be produced in massive amounts. MTM can be used for the large-scale remediation of waste water containing heavy metals via applying a simple and fast magnetic separation.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Filtration and Separation
Authors
Ranjini Nagarajah, Kien Tiek Wong, Gooyong Lee, Kyoung Hoon Chu, Yeomin Yoon, Nam Chan Kim, Min Jang,