How to eliminate the interference of COD digester water sample?

COD digester adopts high-temperature COD reflux digestion mode for timing control heating plate, which can heat
6/8/12 special digestion bottle reflow devices at the same time.

Today Xiaobian to tell you how to eliminate the interference of COD digester water samples: (1) chloride ion is the main interference component, water samples contain chloride ions will make the determination results high, the factory standard C1 reagent can mask 1000mg / L below the chloride ion interference, greater than 1000mg / L chloride ion content, can be diluted and then determined; (2) During the test, Mn(III.
), Mn (VI.
) or Mn (VII.
) forms a red substance cod digester, which will cause a positive deviation, and its 500mg/L manganese solution (sulfate form) causes a positive deviation COD value of 1083mg/L, and its 50mg/L manganese solution (sulfate form) causes a positive deviation COD value of 121mg/L; (3) Under the condition of acidic potassium dichromate, some aromatic hydrocarbon organic compounds, pyridine and other compounds in the cod digester are difficult to oxidize, and their oxidation rate is low
.

(4) The organic nitrogen in the sample is usually converted into ammonium ions, and the ammonium ions are not oxidized
by potassium dichromate.

(5) For results, for samples with high chloride ion concentrations and small COD concentrations, use low-range assays
.

Features of COD digester: 1.
The measured results of nitrogen treatment for high-chlorine samples are better than those without nitrogen treatment
.

2.
The use of microcomputer technology for timing control of the heating furnace, can be 5 digestion reflux devices at the same time heating
.

3.
The use of glass burr return pipe instead of spherical return tube, and air cooling technology to replace tap water cooling mode, both to save water and standardize the instrument, but also to improve the safety
of instrument use.

4.
No need to pour into other bottles, the triangle beaker can be measured after heating, which is convenient to use
.

5.
The purpose of
energy saving, reducing power load and improving efficiency.