Lovibond ® Roewe State, Germany ® water quality analysis

Biochemical Oxygen Demand (BOD) Test

Key points of this article

The pressure difference method for BOD testing is easy to operate and reduces the probability of errors

Lovibond ® Discussion on BOD testing products, methods, and results

BOD analyzer BD 600
constant temperature incubator
BOD test piece
Nitrification inhibitor, absorbent

BOD testing method for high concentration organic wastewater

Biochemical Oxygen Demand (BOD)

Biochemical Oxygen Demand (BODn) is the amount of oxygen consumed by microorganisms during the aerobic decomposition of organic matter over an n-day testing period, expressed in milligrams per liter of oxygen. Typically, the testing period is 5 days (BOD5) or 28 days (BOD28).

BOD reflects the characteristics of water quality and the biological activity of cultivated microbial communities, and is an important parameter for determining the oxygen demand of wastewater treatment and measuring treatment effectiveness. For example, introducing wastewater with high BOD test values can cause insufficient oxygen in waterways, affecting the biological activity of microorganisms. On the other hand, the sewage treatment effect can be checked by comparing the BOD levels before and after sewage treatment.

Test Principle

Microorganisms feed on organic matter in water samples and consume it in the presence of oxygenorganic matter — That is to say,organicThe compound isslightBiological oxidation, partially or * decomposed into carbon dioxide（CO₂）And inorganic salts (mineralization):

organic carbon+ O₂——> CO₂+salt

BOD Differential pressure test：Use potassium hydroxide KOH Microorganisms absorb oxygen and oxidize organic matter from the gas phase of the samplecarbon dioxideTherefore,In a closed system BOD Sample bottle/In the sensor, there will be a pressure drop, and this pressure dropvalueDirectly proportional to the amount of oxygen consumed.

Lovibond^® BD 600

The BOD analyzer measures the pressure changes in the sample bottle caused by oxygen consumption through an electronic pressure sensor and calculates them as mg/l BOD. Compared with the dilution method, this method is very suitable for routine analysis work:
Samples can usually be used without pre dilution;
• Wide measurement range (0-4000 mg/l);
All measurement values are automatically stored;
The BOD curve is intuitively visible;
Reduce the workload and errors of operators;

table1:Lovibond® BD 600 Corresponding testing rangeSample size and required nitrification inhibitor（ATH）Quantity.

BOD testing of high concentration organic wastewater

Some high concentration organic pollutants in wastewater, such as those from the sugar and paper industries, have differences in their carbon, nitrogen, and phosphorus nutrient ratios, which can be directly testedBOD The value is low. If the nitrogen and phosphorus content in the water sample is low and affects the normal biological activity of microorganisms, it is necessary to carry outPreprocessing.

Please refer to the attachment for specific operating steps and analysis methods. If you have any questions or suggestions, please contact Lovibond Water Quality Analysis.