The effects of redox potential on Mn Reduction. 1

[infin]

I was interested in knowing if anyone has managed to oxidise Mn at lower pH levels by increasing the redox potential??

The pH of interest was around the 7-8 mark.

Based on my research it appears you can oxidise Mn at pH of 7 with a redox potential of +0.6 volts, and pH of 8 & redox potential of +0.3 volts. Is this correct??

 

[bimr]

Perhaps you can elaborate on your proposed process.

 

[infin]

My thoughts were to use ozone to lift the redox potential. Other than this I have no idea. Any help would be appreciated.

 

[bimr]

One would think that ozone would oxidize manganese somewhat similiar to the effects of chlorine. Chlorine does not oxidize manganese in a reasonable time (15-30 minutes) at a pH of 7-8.

In other environmental applications, ozone generally costs more than chlorine and requires a higher stoichiometric dosage.

 

[infin]

Thanks for your reply.

If I was to introduce a stream of high dissolved oxygen instead of the Ozone to lift the redox potential do you this could work??

 

[bimr]

Oxidation of manganese is easily accomplished with aeration. The problem is that the reaction time is slow unless the pH is elevated.

 

[infin]

Thanks again bimir,

I understand that Mn can oxidise with aeration and have a slow reaction time unless the pH is high. The research I found mentioned showed that with high redox potential the pH can be lower for faster reaction times.

Thanks for your help I'll do some trials.

Out of interest does anyone have what the reaction times are for various pH levels for Mn??

Thanks again.

 

[bimr]

Water Treatment for Industrial and Other Uses by Eskel Nordell has a discussion of the manganese reaction with pH and time.