In the process of industrialization, large amounts of wastewater are discharged into the environment, causing serious pollution to water resources and the ecological environment. Chemical oxygen demand (COD) is one of the important indicators to measure the organic matter content and pollution degree in wastewater. Many organic compounds dissolved in water absorb UV light. Therefore, by measuring the degree of absorption of 254nm wavelength ultraviolet light by these organic substances, the content of dissolved organic pollutants in water can be accurately measured. The greater the chemical oxygen demand, the more serious the water body is polluted by organic matter. Industrial wastewater usually contains a large amount of organic matter, including chemical plants, pharmaceutical plants, food processing plants and other industries.
These organic matter will decompose in the water body, consume dissolved oxygen, cause water body hypoxia, and form high concentrations of COD due to the degradation of organic matter. The COD value of these wastewater must be monitored when discharged. The COD351 online digital chemical oxygen demand sensor developed and produced by Daruifuno uses ultraviolet absorption method, which can continuously monitor the COD value in water. It has automatic cleaning wiper, digital RS485 interface, and supports Modbus communication protocol. This optical COD probe does not need to consume reagents or wait for a long time, and can display values in real time.