Complete BOD Test Kit manufacturer and supplier. Dissolved oxygen. Biochemical oxygen demand Test kits for measuring Biological Oxygen Demand in water and wastewater for applications ranged 2 - 3000 mg/l O2.
Estimation of dissolved oxygen in water:
Reagents: Manganous sulphate solution Alkali-iodine reagent
Starch indicator
0.00025 No Sodium thiosulphate solution
Procedure:
. 20 mL of sample water was taken in a dry breakers.
. Adding 3 drops of Manganous sulphate solution and 2 drops of alkali iodine solution to it.
. Mix well and allow the precipitate to settle down.
. Adding 2 drops of conc. H2 SO4 and mix well till the precipitate
dissolves.
.20 drops of the above solution was taken in a dry test tube.
. Adding 1 drop of starch to the tube. A blue colour of the solution appears.
. Adding Sodium thiosulphate solution drop wise with a calibrated pipette to the tube till the blue colour disappears.
. Counting the number of drops of Sodium thiosulphate solution used.
Calculation:
Volume of water = No. of drops x Drop value of the pipette = p mL Volume of Na2 S2 O3 = No. of drops x Drop value of the pipette = q mL Dissolved oxygen (ppm) = 2 x q / p
Result: The DO of the sample is ___________mg/L or ppm.
Estimation of BOD of water:
Reagents: Manganous sulphate solution
Alkail-iodine reagent
Starch indicator 0.00025 N Sodium thiosulphate solution Procedure:
. Three vials A, B and C was taken and filled with the water sample.
. Determine the DO of A immediately by adding 1 mL of MnSO4 + 2 mL of H2 SO4.
.ToBadding1mLofMnSO4 +2mLofH2 SO4andkeep for 5 days.
.ToCadding1mLofMnSO4 +2mLofH2 SO4 and2mL of sample water and keep for 5 days.
. After 5 days determine DO of B ( blank bottle) and C (sample bottle).
Calculation:
If the values of DO of the vials A, B and C be a, b and c then
BOD (mg /L) = (b-c) x 1000 / volume of sample in mL.
Result: The BOD of the sample is __________ mg /L.
Reagents:
Manganous sulphate solution Alkali-iodine reagent
Starch indicator
0.00025 No Sodium thiosulphate solution
