AI Article Synopsis
- The study investigated how to reduce hexavalent chromium (Cr(VI)) to trivalent chromium (Cr(III)) using a tubular reactor in both continuous and batch modes.
- It was found that the reduction process involves not just the oxidation of iron from sacrificial steel anodes, but also a secondary reaction where Fe(III) is reduced back to Fe(II), suggesting a catalytic effect.
- The research highlighted the importance of pH levels (1 to 2) on the solubility of the generated species, with significant reductions in chromium concentrations observed, dropping from 1000 mg/L to as low as 0.5 mg/L after treatment times between 25 to 320 minutes.
Article Abstract
This work aimed at studying the electrochemical reduction of the hexavalent chromium Cr(VI) by means of a tubular reactor operating under both continuous and batch regimes. It is shown that chromium (VI) reduction to chromium (III) was exerted not only by the oxidation of iron to Fe(II) released from the steel sacrifice anodes immersed in an acid solution to aid the overall process. Also, it is shown that there was an additional contribution to chromium reduction from an ancillary reaction at the cathode, where Fe(III) ions generated after the Cr(VI) reduction are again reduced to Fe(II), this being interpreted as a catalytic effect taking place. The results are presented at pH values of 1, 1.3, 1.7, and 2: it became clear that the variable affected the solubility of the species generated in solution. The initial chromium hexavalent concentration was 1000 mg L(- 1) and it was found that after treatment times ranging from 320 to 25 minutes this could reach values as low as 0.5 mg L(- 1), depending on the operating conditions.
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| http://dx.doi.org/10.1080/10934520500234742 | DOI Listing |
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