How to choose a BOD detector?

The BOD detector is a new type of instrument for the determination of biochemical oxygen demand by using the air pressure difference method. Note Biochemical oxygen demand or biochemical oxygen consumption (generally refers to the five-day biochemical oxygen demand), a comprehensive indicator of the content of oxygen-demanding pollutants such as organic matter in water. Explain the total amount of dissolved oxygen in the water consumed when the organic matter in the water is oxidized and decomposed due to the biochemical action of microorganisms to make it inorganic or gasified.

Under normal circumstances, it means that the water sample is filled with a closed dissolved oxygen bottle, cultured in a dark place of 20 °C for 5 days, and the mass concentration of dissolved oxygen in the water sample before and after the incubation is measured respectively. The amount of dissolved oxygen consumed by the sample is expressed as BOD5. It is expressed in units of ppm or mg/L. The higher the value, the more organic pollutants in the water and the more serious the pollution.

What are the methods of BOD determination?

1. Five-day culture method: The five-day culture method needs to be used with a special biochemical incubator, and it takes at least five days to obtain the required data;

2. Rapid determination of microbial film: The rapid determination of microbial film only requires culturing the microbial film. Generally speaking, it only takes 24-48 hours to cultivate, and the measurement data can be obtained after only 5-8 minutes.

How to choose a BOD detector?

Confirm the required method:

1. Five-day culture method

a. Mercury pressure difference (need to inject mercury to watch the scale to get the required data);

b. Mercury-free differential pressure (digital display type, no need to contact mercury, the screen displays data directly);

2. Rapid Assay of Microbial Films

a. Flow-through microbial assay

b. Portable. Going out for field testing

c. Online (installed on-site, real-time monitoring of BOD value).