On-Line KMnO4 concentration monitoring

[mmanetta]

I am looking for an instrument or method to monitor the concentration of 3 wt % KMnO4/H2O solutions on-line for a scrubber application. I would like to automate the process to inject the concentrated KMnO4 solution when the feed concentration drops below 3%. I am considering conductivity but since it is not selective I will have to make assumptions about TDS. Another method I have found is automated titration, which is expensive. Does anyone have any other suggestions?

 

[hacksaw]

ORP should do the trick. Several suppliers are available depending on the severity of your service.