In complex environments such as hospitals, disinfection must be carried out before wastewater discharge. For this reason, the design and construction of medical wastewater treatment facilities should proceed simultaneously with the main project, so as to prevent the generation of new pollution sources. Meanwhile, consideration must be given to the separate collection and treatment of wastewater from infectious disease wards to ensure sufficient pollution control capacity. This article discusses the classification and management of wastewater treatment systems.
Common disinfection methods and their advantages and disadvantages in hospital wastewater treatment stations
To properly treat wastewater, it is first necessary to distinguish disinfection methods and their characteristics, and then select an appropriate one based on actual conditions to ensure disinfection efficiency and economic viability. Several common disinfection methods are described below:
1.Ozone disinfection
Advantages: short contact time, high efficiency, and low susceptibility to external interference.
Disadvantages: high energy consumption, strict requirements for the gas source, and the need for off‑gas treatment. In addition, ozone has a short half‑life and cannot maintain disinfection effects in the pipe network.
2.Chlorine dioxide disinfection
Advantages: strong adaptability to water quality, minimal influence from pH value, and stable disinfection performance even for ammonia‑containing wastewater.
Disadvantages: hydrochloric acid used in the process is highly corrosive and hazardous to humans and equipment. As a Category III precursor chemical for illicit drugs, chlorine dioxide requires registration, certification, and qualification approval from relevant authorities for purchase and storage, which poses additional management challenges.
3.Sodium hypochlorite disinfection
Advantages: rapid action, reliable bactericidal effect, and convenient operation.
Disadvantages: high corrosiveness, similar to chlorine dioxide, and relatively unstable disinfection effect due to rapid chlorine dissipation.
4.Physical disinfection methods
In addition to chemical disinfection, physical and biological methods are also applied, such as ultraviolet (UV) disinfection.
Advantages: high efficiency, small footprint, high safety, and easy operation and maintenance. Compared with chemical methods, it is less affected by environmental conditions.
Disadvantages: disinfection efficiency decreases significantly when the wastewater contains high levels of suspended solids.
There are many other wastewater treatment technologies available, and the above are only some common options. Facilities should select appropriate treatment processes according to their actual conditions.
Monitoring of treated hospital wastewater
Treated hospital wastewater is not discharged directly. Instead, strict monitoring is required to verify that all indicators meet discharge standards. In addition to inherent harmful substances in water, byproducts generated during disinfection must also be monitored.
For example, when chlorine‑containing disinfectants are used, total residual chlorine in the effluent must be monitored. The RCl900 Online Total Residual Chlorine Analyzer can be used for real‑time monitoring of residual chlorine in wastewater.
