Rate of Fenton Reaction

I want to determine rate of Fenton reaction with different concentration of $\ce{Fe^2+}$. These are some questions that I have encountered:

1. How long does it usually take for the reaction to complete?
2. What concentration of $\ce{Fe^2+}$ is usually used for the reaction?
3. I am planning to use titration of $\ce{H2O2}$ with $\ce{KMnO4}$ to determine the rate of reaction. Is it possible to quench to reaction mixture by adding an excess of EDTA solution and would it affect the titration?

NEW:

How can I determine the rate of Fenton reaction? I proposed to titrate H2O2 with KMnO4 to determine change in H2O2 as a mean of determining rate of reaction. However, I realised that KMnO4 would also react with Fe2+, so I need to either find another way to measure the reaction rate or find a way to remove all Fe2+. Also, I am not sure if there would be any reaction between KMnO4 and the hydroxyl radicals.

I am also wondering about adding in some wastewater and determine the before and after COD to determine the rate of reaction. However, I am wondering if the water that don't really have high COD (as opposed to the industrial wastes used in other papers) would result in a very slow reaction rate. Also, it seems like the part involving oxidizing by hydroxyl radicals is very exothermic. If I don't want to add H2O2 bit by bit to control rate of reaction, is it ok?

Do I have to add acid to Fe2+ and H2O2 for the reaction to occur?

Is it necessary to add H2O2 bit by bit, if so how much should I add at each turn?