Chemical Forums

Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: 2min2midnight on April 03, 2018, 03:17:00 AM

Title: Chelating potential of a solution
Post by: 2min2midnight on April 03, 2018, 03:17:00 AM
Hello all,

I have a mixture that contains different organic chelating agents. I am trying to run a Fenton oxidation for COD reduction. Problem is that chelating agents remove the iron from the catalytic circle. To overcome that figured that I first have to determine how much chelating "power" the solution has, add that much iron, then add extra for the Fentons reaction.

If anyone has any suggestions how to go about this I would be very grateful. The uni has a very strong laboratory so I can attempt differenty analytical methods.

Thanks again!
Title: Re: Chelating potential of a solution
Post by: franz1973 on May 04, 2018, 07:09:05 AM
At work I have to detrmine "sequestering power" on detergents. I do this way: weigh about 1g of the substance (write the weight) then add about 80ml of distilled water (just to dilute a little) and 10ml of Na2CO3 2% solution. This way you are in excess of carbonate ions. Add drop by drop a solution of Calcium Acetate 44,1g/l while stirring. CaCO3 starts to precipitate but dissolves as the detergen sequesters calcium. Stop when you see turbidity no more disappear. So calculate the "power" by this formula

POWER=(CaAc ml used / g of substance) x 25

This gives to you the mg of CaCO3 captured (dissolved) by your product
I don't understand the formula and the method is subjective but I have no other ways