Advantages and disadvantages of COD national standard method measuring instrument and rapid method

COD national standard method tester is composed of a special digester and a special colorimeter, with functions such as automatic temperature control, timing, zero adjustments, linear regression, curve storage and data printing. Due to the strong oxidant used in the measurement process, it is highly corrosive. A little carelessness will cause serious corrosion to the instrument and the oxidant delivery system. For this reason, we have developed a unique automatic air pressure sampling method to avoid possible corrosion. The COD national standard method measuring instrument can be widely used in environmental protection, scientific research monitoring, production monitoring and other fields, and is an ideal machine for environmental monitoring and control.

Introduction to the advantages and disadvantages of COD national standard method tester and rapid method:

1. The COD national standard method uses a large number of reagents, which causes great secondary pollution to the environment, while the rapid method uses only one-sixth of the reagents of the national standard method, and the harm to the environment is greatly reduced accordingly.

2. The reagent cost of the COD analyzer rapid method is less than half of that of the national standard method.

3. The national standard method requires reflux heating for 2 hours. During the reflux process, a large amount of sulfuric acid vapor and heavy metal salts are volatilized in the air, which seriously threatens the health of operators. However, the rapid method only needs to be digested for 10 minutes, and all the amount of reagents added is greatly reduced, and there is almost no volatilization of sulfuric acid vapor in the whole process, which effectively protects the health of the experimenters.

4. The COD national standard method tester takes a long time. It only takes 2 hours for heating. It takes at least one morning to do the most experiments every day. With the fast method, it only takes less than 1 hour, which greatly improves the work. efficient.

5. The operation process of the national standard method is very complicated. It needs to add solid mercury sulfate, and also needs to add potassium chromate standard solution and silver sulfate solution. After refluxing and heating, it needs to be titrated with a ferrous standard solution, and ferrous iron is easily oxidized. , the national standard requires calibration before each use, which greatly increases the burden of the experimenter and increases the uncertainty of the experimental results. The rapid method only needs to add two reagents, and the built-in curve can be used to directly read the concentration for determination.

6. Since the national standard method titration adopts manual visual inspection of the titration end point, the possibility of human error is high, especially when the workload is very large, the probability of such errors is greatly increased. The rapid method is to read the concentration directly by the instrument, and the reagent is also a standard solid reagent provided by the manufacturer, and the liquid is added by a special quantitative device, which eliminates human error.

COD national standard method measuring instrument is used as a comprehensive index to measure the pollution degree of sewage. The detection of COD is particularly important. There are many methods for measuring COD, such as the dichromate method, potassium permanganate method, spectrophotometry, rapid Digestion method, rapid digestion spectrophotometry, etc.