Domestic sewage also requires rigorous disinfection and monitoring.  

Sewage refers to contaminated wastewater generated from daily life or industrial production processes. Historically, a simplistic disposal approach involved direct discharge into rivers, yet this practice poses inherent risks.  

While sewage exhibits superior water quality compared to wastewater, it still necessitates treatment to prevent contamination of river water sources, thereby safeguarding the ecological environment and human health. Domestic sewage, specifically, encompasses wastewater generated from routine domestic activities (e.g., face washing, vegetable cleaning, handwashing). Notably, wastewater presents greater challenges in purification and treatment, whereas other forms of contaminated water are classified as sewage.  

Consequently, sterilization and online monitoring of domestic sewage are of paramount importance. Following chemical disinfection, operators utilize water quality monitors to conduct real-time online analysis of key parameters in sewage, with distinct instruments employed for different indicators. The primary monitored parameters include:  

1.Biochemical Oxygen Demand (BOD)

BOD denotes the amount of dissolved oxygen required by aerobic microorganisms in water to decompose organic matter into inorganic substances at a specified temperature within a defined timeframe. It serves as a comprehensive indicator of organic pollutant levels in water.  

2.Chemical Oxygen Demand (COD)  

COD represents the amount of oxidant consumed to chemically oxidize reducing substances (predominantly organic pollutants) in water. Higher COD values indicate more severe water pollution.  

3. Additional routine parameters are also monitored but are not elaborated here. Bacterial contaminants—such as total bacterial count and coliforms—are equally critical, as their presence in water can pose health hazards. Thus, strict supervision is imperative to ensure the safe discharge of domestic sewage.