Development and optimization of magnetic technologies based processes for removal of some toxic heavy metals |
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Authors: | E H Borai E A El-Sofany T N Morcos |
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Institution: | (1) Hot Labs. Centre, Atomic Energy Authority, P.O. Code 13759, Cairo, Egypt |
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Abstract: | In the developing countries where the cost is often a decisive factor, extensive studies were undertaken to test the most
effective factors on the preparation, optimization and validation of the magnetic particles (or, more accurately, magnetizable
particles) for removal of heavy metals from wastewaters. The objective of the proposed work was focused to provide promising
solid-phase materials, which, are relatively in expensive and combine high surface capacity with fast efficient treatment.
Four various metal oxides including hydrous ferric oxide (HFO), hydrous stannic oxide (HSO) and mixed ferric/stannic oxide
(HMO), were prepared by precipitation with ammonia from metal chloride solutions. Two mixed oxides were prepared with different
Sn/Fe ratios of 50% and 20%. Optimal conditions for the activation of these particles and the subsequent mixing of various
metals oxides are tested together with the utility of the method to get a new composite material with developed chemical characteristics
over their individual metal oxides. Factors affecting the sorption behavior of the prepared samples in basic and acid media
were elucidated. The magnetic treatment procedure using the mixed oxide (50%) enables the equilibration step to be carried
out rapidly mainly due to ferric oxide during the magnetization process and efficiently due to high capacity of the stannic
oxide. A key factor in achieving very high uptake percentage is the reduction of non-specific binding of various heavy metals
to the solid phase support. This is usually achieved by increasing the ion exchange capability, in addition to their adsorption
process. |
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Keywords: | Heavy metals Magnetic technology Composite oxide |
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