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Removal of EDDS and copper from waters by TiO2 photocatalysis under simulated UV–solar conditions
[Display omitted] •Simultaneous EDDS oxidation and Cu(II) reduction through TiO2 solar photocatalysis.•Evaluation of the influence of several operating conditions on system reactivity.•The oxidation of EDDS proceeds mainly through the interaction with positive holes.•Simplified reaction pathways for...
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Published in: | Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2014-09, Vol.251, p.257-268 |
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Main Authors: | , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | [Display omitted]
•Simultaneous EDDS oxidation and Cu(II) reduction through TiO2 solar photocatalysis.•Evaluation of the influence of several operating conditions on system reactivity.•The oxidation of EDDS proceeds mainly through the interaction with positive holes.•Simplified reaction pathways for EDDS photocatalytic oxidation are proposed.•The process is capable to reduce the ecotoxicity of the Cu/EDDS solution.
The TiO2 photocatalytic oxidation of the N,N′-ethylenediamine-disuccinic acid and Cu(II) ions photoreduction were investigated in acidic solutions. The experimental results indicated a conversion of 100% for both EEDS and Cu(II) species whereas the mineralization degree was quite small (24%). The influence of several experimental variables, like purging gas, counter ion nature, pH, TiO2 type, photocatalyst load, initial concentration of cupric ions, radiation source (natural or artificial), was investigated. For almost equimolar feed ratios of reactants, EDDS was not totally removed whereas Cu(II) species were completely reduced. An analysis of the data collected indicated a Cu(II)/EDDS molar consumption ratio close to two.
The presence of oxygen decreased the photoreduction process of Cu(II) species, whereas the initial concentration of Cu(II) ions and the counter ion (excepted for the chloride ions) did not affect the photocatalytic process. Ecotoxicity tests (Pseudokirchneriella subcapitata and Lemna minor) on treated samples indicated a marked decrease of the ecotoxicity for very prolonged reaction times. |
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ISSN: | 1385-8947 1873-3212 |
DOI: | 10.1016/j.cej.2014.04.066 |