LaMotte BOD5 TEST KIT BOD - Manual (Page 2)

To order individual reagents or test kit components, use the specified code
number.
Carefully read the instruction manual for the LaMotte Automatic Buret before
performing the test procedure. The buret is calibrated in parts per million (ppm)
Dissolved Oxygen, accuracy to within 0.1 ppm.
INTERFERENCES
Caustic alkalinity, mineral acid, free chlorine, and heavy metals are among the
factors that may influence test accuracy. BOD bottles must be extremely clean to
maintain consistent test results.
WASTEWATER PRETREATMENT
NOTE: Pretreatment reagents are not supplied with this kit.
The pH of the sample should be in the range of 6.5 to 7.5. Adjust samples with
either 1N Sodium Hydroxide or 1N Sulfuric Acid to bring within this range.
Samples with free chlorine should be treated with 0.025N Sodium Sulfite
solution.
DILUTION WATER MAKEUP
Add 1 mL each of Phosphate Buffer, pH 7.2 (2843), Magnesium Sulfate, 1.10%
(3761), Ferric Chloride, 0.015% (3760) and Calcium Chloride, 2.75% (3756)
solutions for each liter of distilled water. Store at temperature as close to 20°C as
possible. This water should not show a reduction in dissolved oxygen of more
than 0.2 mg/L on incubation for 5 days.
Follow instruction accompanying “Polyseed” capsule when using seed to
determine BOD
5
.
PRO CE DURE FOR BOD DE TER MI NA TION
1. Determine the amount of sample(s) to be added to a 300 mL BOD bottle.
Table I can be used to estimate the amount of sample to add to the BOD
bottle. Raw municipal wastewater usually contains about 100 to 300 mg/L
BOD
5
, so 3-6 mL of sample water is used. For primary and secondary treated
effluents, 45-75 mL samples should be used. Refer to Table I for other ranges.