The BOD tester is based on the national standard "HJ505-2009" 5-day culture method, simulates the biodegradation process of organic matter in nature, and uses a simple, safe and reliable mercury-free differential pressure sensing method to measure BOD in waterFully intelligent design and design manufacturing, the experimental process does not need to be attended by experimenters;It is suitable for the determination of biochemical oxygen demand in monitoring stations, sewage treatment plants, third-party testing institutions, scientific research, universities and other fields.
BOD analyzer is a very common water quality monitoring instrument used to determine biological oxygen demand in water. In the environmental protection and sewage treatment industry, BOD testers play a vital role.
How to use the BOD tester:
1.Calibrate the instrument.
Before each use of the BOD tester, the instrument needs to be calibrated to ensure the accuracy and reliability of the measurement results. In general, calibration involves adjusting the electrode, diluting and normalizing, based on blank water, low concentration standard solution, and high concentration standard solution, respectively, according to the instrument adjustment instructions.
2.Sampling and preparation.
Before proceeding with a BOD determination, a water sample must be taken and the quality of the water sample must be intact, and in general, it is best to test no more than 6 hours after the sample is collected.
Proper preparation must be carried out before sampling, first, the water sample must be stirred in a proper manner. Since BOD is formed by the splitting of organic compounds in water by oxygen, agitation ensures that the organic content in the water sample is evenly dispersed.
Secondly, proper dilution must be carried out according to the concentration of the water sample, the higher the concentration of the water sample, the longer the time required for the measurement, therefore, for the water sample with high concentration, the appropriate dilution must be carried out to ensure that the measurement time is not too long, affecting the accuracy and precision of the test.
3.Add the reagent.
The reagent used in the BOD tester is generally white particles, called "cotin salts". Prior to testing, cotin salts are added to the sample and the water sample is gently stirred to ensure that the reagents are evenly mixed. The amount of reagent added is usually 10% of the volume of the water sample, and the reagent will bring oxygen to the organic matter in the water sample, which will be broken down into inorganic matter and carbon dioxide will be released.
4.Measurement. The sample was injected into the BOD measurement soil layer and sealed, and the sample was allowed to stand at room temperature or human body temperature for 5 days, and after 5 days, the carbon dioxide absorption of the scum and the unabsorbed carbon dioxide in the aqueous solution were analyzed and the data were compared.
The content of biological oxygen demand in the water is calculated based on the carbon dioxide absorption value of the test scum and the standard reagent dosage, the concentration of the sample and the amount of water sample. BOD values are usually expressed in mg L units.
5.Process the results.
Usually the BOD value measured by the BOD analyzer needs to be compared with some standards to judge whether the water quality meets the requirements. If the BOD value in the water sample exceeds the standard value, then some adjustment may be required to find out the cause of the contamination and take the necessary measures to solve it.
BOD tester liquid crystal display, a new type of instrument for BOD determination using air pressure difference method, can accurately provide comparable measurement results with chemical dilution method, directly display BOD value, biochemical reaction curve at a glance, is an ideal instrument, can be widely used in environmental testing, petrochemical, medical and health, teaching and scientific research and other departments to detect water quality.
Biochemical oxygen demand refers to the amount of dissolved oxygen consumed in the process of microbial decomposition of certain oxidizable substances, especially organic matter, in the process of microbial decomposition in water, which is an important data index to measure the water pollution of organic matter, and is widely used in the determination of surface water, domestic sewage and industrial sewage, and is suitable for sewage treatment plants, various high-tech biological laboratories and environmental protection monitoring departments, university laboratories and analysis and testing centers.
In order to meet different needs, the tester has increased data storage, printing and USB interface, which is convenient for data transfer to the computer, the device is a portable instrument, with built-in large-capacity batteries, power failure protection, one-key factory reset and other functions. The instrument is placed in the incubator, and the quantitative volume of water sample is poured into the culture flask according to the pre-selected range and measurement range, and the stirrer is continuously stirred.