I am working on catalytic wet air oxidation of organic pollutants. During the study I found that there are some organic acids (formic acid, acetic acid etc.) as transformed product. Literature suggests that formic acid is a good reducing agent for Cr(VI). With the aim of reducing Cr(VI) to Cr(III) in the same system, I used organic pollutant and potassium dichromate solution mixture in the CWAO reactor. Color reduction is visually noticed with the reaction time. Cr(VI) reduction with reaction time was observed by DPC method. When reaction samples were analyzed by Atomic absorption spectroscopy for total Cr, the concentration were found similar as Cr(VI). This means there was no Cr(III) in the transformed product. I am wondering where the disappeared Cr going on? It may adsorbed on catalyst surface but separate experiments suggest that Cr adsorption capacity of the material is lesser that the disappearing Cr amount. Please feel free to discuss if there require some more information.
Thank in advance.
Regards,
Arun
First, Cr is toxic and can't be applied for water purification.
Second, I don't understand the problem. DPC method measures Cr(VI), the total Cr remains unchanged. The difference is the reduced Cr.
Dear Prof. Yurii V Geletii,
Cr(VI) is toxic. I am trying to treat a water containing Cr(VI).
Did you read my answer: "DPC method measures Cr(VI), the total Cr remains unchanged. The difference is the reduced Cr."
Yes Sir I read that. I know the fact you have suggested. I am not getting any difference (i.e. Cr(III). But the initial Cr (VI) amount is decreasing with reaction time. Perhaps those are getting adsorbed on catalyst surfaces.