Investigations on iron and aluminium oxides and oxyhydroxides based sorbents for the removal of arsenic from groundwater
Queen's University Belfast, 2014
Online
Hochschulschrift
Zugriff:
This thesis presents investigations on the use of various iron and aluminium oxides, and oxyhydroxides based sorbents for the removal of arsenic from groundwater via adsorption processes. Three main types of materials were employed: (i) a natural ore and an industrial by-product; (ii) organised mesoporous silicas (OMS) coated with iron and aluminium, and: (iii) metal oxyhydroxides produced from industrial coagulants solutions (FAS(OH)s). The synthetized materials were optimised with respect to adsorption capacity and all the sorbents were fully characterised. The OMS were coated with various ratios of Fe and AI oxides with a view to tailoring the As(III)/As(V) selectivity of the adsorbents. The effects of pH, arsenic speciation and concentration. and adsorbent dosage on the adsorption of arsenic were investigated in a series of batch experiments as well as the different adsorption mechanisms. A kinetic investigation was undertaken with the effect of particle size on the adsorption process and the diffusion of the As species within the solid matrix of the absorbents were investigated. The most promising materials with regard to adsorption capacity were then employed in small scale columns, for evaluation of performance in a continuous process. Several aspects from these investigations were considered and discussed with regard to the potential use of the materials in full-scale fixed bed adsorption units. First the effect of common dissolved ions on the adsorption efficiency of the materials was studied and a reconstituted groundwater was used for comparison purposes. The regeneration of saturated adsorbents using various chemicals was investigated. In a further study, the metal oxyhydroxide powder adsorbent was agglomerated into a granular material and used in subsequent adsorption experiments. Finally, a full scale adsorption unit was designed employing the optimal adsorbent material, which may result in a 50 % smaller footprint unit when compared to existing technologies.
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Investigations on iron and aluminium oxides and oxyhydroxides based sorbents for the removal of arsenic from groundwater
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Autor/in / Beteiligte Person: | Glocheux, Y. |
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Veröffentlichung: | Queen's University Belfast, 2014 |
Medientyp: | Hochschulschrift |
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