As an important means to prevent and control sewage, water quality monitoring has been paid more and more attention by the national environmental protection department.
Chemical Oxygen Demand-(COD) is one of the most important indicators. Chemical oxygen demand directly reflects the extent of water resources being destroyed by reducing pollutants.
If the median value of water is high, the pollutants will consume more dissolved oxygen in the water, resulting in water anoxia, resulting in the death of a large number of organisms due to anoxia.
At the same time, causing a large number of anaerobic bacteria in the water, accelerating the deterioration of water quality.