Methods
COD test method typically consists of both dichromate EPA, ISO and mercury free method. Water sample is chemically oxidised by digesting the sample in a seal reaction tube (known to most as COD reagent). The COD reagents contain highly concentrated sulphuric acid and potassium dichromate in the presence of a silver sulphate catalyst. The amount of dichromate reduction is proportional to the COD presence in the sample. The results of COD concentration are expressed in mg/L.
3 types of reagents
There are 3 different ranges or tests whom user can select from: 150 mg/L, 1,500 mg/L and 15,000 mg/L. If the local discharge limit for COD is 600 mg/L, we will advice to select the mid range 1,500 mg/L. This range is mainly to use to check effluent, after treatment process. However, plant operator may want to check the efficiency of their treatment process, therefore they would like to monitor the higher range and mid range of their COD concentration. User can perform dilution to their higher COD value so that it will fall within the 1,500 mg/L range and multiply the readings by the dilution factor. Or they can choose to buy a higher range of COD reagents at 15,000 mg/L.
Equipments needed
Equipments needed as below:
- COD Analyser (Bench-top or portable)
- COD digestor
- Adjustable Micropipette (0~1000uL)
New to COD Testing?
If you have no experience in conducting this test, we can help you training your personnel on site in the right way of doing the COD testing. We can offer package solution of providing all equipments and reagents, and 3 comprehensive trainings (Span of 3 months) in educating your team on the procedure of performing the tests, precaution, common mistakes, safety aspect, so that your team will understand the methodology of COD testing. If you have a team of 3 or more, we can customise the training to that particular group of learners too.
Online COD analyser and Bench top Multiparameter Meter option:
H2O Engineering & Trading 