Topic: Standard method for measuring COD levels? (Read 2602 times)

B · « **on:** July 09, 2012, 07:57:12 AM »

Hi, is the open reflux method using potassium dichromate the best method (standard?) for determining COD levels in liquids?

cheers

tlahren · « **Reply #1 on:** July 23, 2012, 12:04:54 PM »

Pretty much, yeah. EPA standard: http://www.caslab.com/EPA-Methods/PDF/EPA-Method-4104.pdf
HACH sells tubes with premixed reagents. Beware, some come with Hg to reduce chloride interference. If using non-Hg reagent then Cl content must be measured and shown to be below interference levels. Many people use/reference the HACH 8000 method when doing CODs: http://www.d.umn.edu/~dlong/Envengrinfo/Instruction-COD-HR-TNT822.pdf This method references EPA method 5220D.

Hope this helps a little.