Biological Oxygen Requirement (BOI) determination measurement

Determination of Biological Oxygen Demand (BOD) Determination
Determination of Biological Oxygen Demand (BOD) Determination

Biological Oxygen Demand (BOD) or biochemical oxygen demand is a chemical process that determines how fast the oxygen in the water is consumed by the micro organisms in the water. In other words, the need for biological oxygen refers to the amount of oxygen required to decompose the organic matter present in the water by the microorganisms present in the water. Environmental engineers are most interested in this issue.

While building and operating wastewater treatment plants, biological oxygen demand values ​​are needed. The high level of pollution in a water indicates that the pollution level of the water is very high.

The world-standardized and standardized method used by accredited laboratories to determine the biological oxygen demand is BOI5 tests. After performing the necessary tests in this method, the samples are kept under dark and room temperature for five days and the result is reached.

The biological oxygen demand is the amount of dissolved oxygen used by the micro-organisms to oxidize the organic matter in the sample of water taken, at a temperature of 20 degrees, within a specified time and under defined conditions. There are many factors that determine this amount. For example, the concentration of organic matter that can be degraded in water, the structure, number and adaptation of microorganisms, the amount of nutrients for microorganisms, temperature, light and toxic substances.

Most wastewaters contain substances with high oxygen demand. Thus, the amount of dissolved oxygen present in the dilution water is not sufficient. Therefore, it is necessary to facilitate the development of micro-organisms in wastewater by chemical means. The time required for the sample to be completely stable is very long. Therefore, a standard incubation period of five days was accepted and the BOD values ​​measured at five days were defined as BOI5. With this method, the needs of carbonated and nitrogenous materials in wastewater can be measured separately.