Speaking of sewage, it refers to the contaminated water that is no longer in use and generated during daily life or production activities. Simply discharging such sewage directly into rivers and lakes is inappropriate and problematic.

Although domestic sewage has better water quality compared with industrial wastewater, it still requires proper treatment to prevent river and lake water sources from being polluted, thereby avoiding adverse impacts on the ecological environment and human health. Taking domestic sewage as an example, it simply refers to the used dirty water from daily life (such as water from face washing, vegetable washing, hand washing, etc.). Industrial wastewater is more difficult to purify, while other types of contaminated water can generally be classified as sewage.

In this context, sterilization treatment and online monitoring of domestic sewage are of great significance. After chemical disinfection, staff conduct online monitoring of various indicators in sewage through water quality monitors, with different instruments used for different parameters. The key monitoring indicators include:

1.BOD (Biochemical Oxygen Demand): It refers to the amount of dissolved oxygen required by aerobic microorganisms in water to decompose organic matter into inorganic substances within a specified time and at a certain temperature. It serves as a comprehensive standard for measuring the content of pollutants in water.

2.COD (Chemical Oxygen Demand): A high COD value indicates a large amount of reducing substances, mainly organic pollutants, in the water. The higher the COD, the more severe the water pollution.

In addition to the above two indicators, there are other conventional ones that will not be elaborated on here. Bacterial pollutants are also critically important, such as total bacterial count and coliform group. Their presence in water can cause certain hazards, so strict supervision in this regard must be implemented to ensure the safe discharge of domestic sewage.