Differences in COD digestion time

Chemical oxygen demand (COD) reflects the degree of water pollution by reducing substances and is also an indicator to characterize the degree of organic pollution in water. The measurement of COD value in my country basically adopts the dichromate method (also known as the standard reflux method). shortcoming. The practical permanganate index tester is designed and developed according to the national standard GB11892-89, adopts imported optical components, and has stable and reliable performance. 5-inch large screen display, the interface is simple and easy to understand, and the user can use it quickly and accurately. It can be widely used in colleges and universities, scientific research institutes, sewage treatment plants, environmental monitoring stations, municipal engineering, and other industries to detect water quality.

In order to improve the work efficiency, rapid digestion spectrophotometry is now used instead of the standard reflux method to measure the COD value, and the digestion effect under different digestion times is studied, in order to shorten the digestion time, improve the work efficiency, and improve the work efficiency under the premise of ensuring the digestion effect. Good service for environmental management and decision-making.

The analyzers developed and produced all use the rapid digestion spectrophotometry method, which has good precision and accuracy, and the relative error with the measurement results of the standard reflux method is small, and it has the feasibility of replacing the standard reflux method. Considering that industrial wastewater, domestic sewage, and surface water contain different organic matter components, the optimal digestion time required is different. In this study, the optimal digestion time of industrial wastewater was determined by experiments to be 15min, and the optimal digestion time of domestic sewage and surface water was 15 minutes. The digestion time was 15 min.

The improved COD analyzer selects the appropriate digestion time according to the different types of analyzed water samples, and shortens the digestion time, so that the COD analyzer method retains the advantages of the standard reflux method, simplifies the operation steps, and relatively shortens the digestion time. Therefore, compared with the standard reflux method, the COD analyzer is more suitable for supervisory monitoring of larger batches, stable water quality components, and emergency law enforcement monitoring.