Preparation of chemicals for BOD

4 solution required to be added into the sample:

To make 1L solution:

• Phosphate buffer solution

8.5g of potassium dihydrogen phosphate (KH2PO4)

33.4g of sodium hydrogen phosphate heptahydate (NA2HPO4.7H20)

1.7g of Ammonium chloride (NH4Cl)

21.75g of Dipotassium hydrogen phosphate (K2HPO4)

*add all up and top up with distilled water till the level

• Magnesium sulphate

22.5g of MgSO4 + distilled water

• Calcium chloride

27.5g of CaCl2 + distilled water

• Ferric chloride

0.25g + distilled water