Zn-Al sulphate layered double hydroxide for Mo uptake

FRAU, FRANCO;ARDAU, CARLA;DORE, ELISABETTA;LATTANZI, PIERFRANCO

2012-01-01

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Abstract

The efficacy of synthetic Zn-Al-SO4 LDH (layered double hydroxide) in removing aqueous molybdate was tested through batch sorption experiments. Up to 54% Mo was removed; the most efficient mechanism was sulphate-molybdate exchange within the LDH interlayer. The Mo uptake was influenced by the Zn/Al molar ratio: higher ratios (Zn/Al = 3) facilitated the release of sulphate from the interlayer and the entrance of molybdate, while for lower ratios (Zn/Al = 2 and 1.7) surface adsorption of molybdate became an important uptake mechanism. The Mo removing potential shown by Zn-Al-SO4 LDH may prove useful for the treatment of moderately contaminated waters from metallurgical and mining activities.