Background
In recent years, people have paid more attention to water pollution. The monitoring of water quality COD sensors (Chemical Oxygen Demand) is gradually being valued by people. Water quality COD means the amount of oxygen required for potassium dichromate to oxidize organic matter in one liter of sewage under strong acid conditions. It can roughly indicate the amount of organic matter in sewage. COD is an important indicator of organic pollution in water bodies, which can reflect the pollution degree of water bodies. The so-called chemical oxygen demand (COD). It is under certain conditions. When a certain strong oxidant is used to treat water samples. The amount of oxidizer consumed. It is an indicator of the amount of reducing substances in the water. The reducing substances in water include various organic substances, nitrites, sulfides, and ferrous salts. But the main thing is organic matter. Therefore, chemical oxygen demand (COD) is often used as an index to measure the amount of organic matter in the water. The greater the chemical oxygen demand, the more serious the pollution of the water body by organic matter. The online bod cod analyzer is very important.
Studies have found that organic matter has a maximum absorption value in the ultraviolet region of 254 nanometers. Therefore, the absorbance at this wavelength can be measured. The water suspension absorbs visible light at 900 nanometers. The absorption of organic matter is almost zero. Therefore, it can be divided into two paths of light, by measuring the degree of absorption of the two paths of light. The COD value of water quality can be obtained.
Extended information
High chemical oxygen demand means that the water contains a lot of reducing substances. Among them are mainly organic pollutants. The higher the chemical oxygen demand, the more serious the organic pollution of the river water. The sources of these organic pollution may be pesticides, chemical plants, organic fertilizers, etc. If not treated, many organic pollutants can be adsorbed and deposited by the bottom sludge at the bottom of the river. In the next few years, it will cause long-lasting toxic effects on aquatic organisms. After a large number of aquatic life died, the ecosystem in the river was destroyed. A high chemical oxygen demand does not necessarily mean the aforementioned hazards.
Specific judgments need to be analyzed in detail. Such as analyzing the type of organic matter. What is the impact on water quality and ecology? Is it harmful to the human body? If it is not possible to conduct a detailed analysis. The chemical oxygen demand can also be measured on the water samples at intervals of a few days. If compared with the previous value, the value drops a lot. It shows that the reducing substances contained in the water are mainly easily degradable organic substances. The harm to human body and biology is relatively light.