Definition of Medical Wastewater  

Medical wastewater refers to effluents discharged by hospitals into the natural environment or urban sewage pipelines, primarily originating from areas such as laboratories, canteens, wards, and laundry facilities. In addition to components typical of domestic sewage, this wastewater contains chemical substances and radioactive materials, necessitating disinfection prior to discharge. Chlorine-based disinfection is a conventional method for medical wastewater treatment; however, strict control of total residual chlorine (TRC) is required during this process to prevent non-compliance. The core question thus arises: what are the standards for residual chlorine detection in medical wastewater?

Control of Chlorine Disinfectant Dosage  

The dosage of chlorine disinfectants is determined by multiple factors, with exposure time being critical: shorter exposure periods require higher disinfectant dosages. Additionally, an RCl900 Online Total Residual Chlorine Analyzer should be installed at the discharge outlet to monitor TRC levels in real time, ensuring compliance with regulatory limits.

Standards for Residual Chlorine Detection in Medical Wastewater  

According to China’s national standard GB 18466-2005 Discharge Standard of Water Pollutants for Medical Institutions, the TRC requirements for chlorine-disinfected medical wastewater are as follows:

1.Direct discharge into natural water bodies:

If wastewater is discharged directly into seas, rivers, or other natural water bodies, dechlorination treatment must be conducted to reduce TRC to less than 0.5 mg/L.

2.Wastewater containing infectious pathogens:

For pathogen-contaminated wastewater treated with chlorine-based disinfection, if the contact time in the disinfection tank is ≥1.5 hours, TRC at the outlet of the contact tank should be controlled within the range of 6.5–10 mg/L.

3.Wastewater from general medical and other institutions:  

· For disinfection processes with a contact time ≥1 hour, TRC at the outlet should be 3–10 mg/L.

· For pretreatment processes, TRC at the outlet should be 2–8 mg/L.

Note: The above standards apply exclusively to chlorine-based disinfectants. No TRC requirements are specified for wastewater disinfected with alternative agents.

In Medical Wastewater Online Monitoring, TRC detection is only one of the key indicators. Other parameters, including coliform counts and routine physicochemical indices, must also be monitored in real time to ensure all discharge standards are met before effluent release.

Key Adjustments for Academic Context:  

1.Terminology Standardization: Replaced colloquial expressions (e.g., “problem is that,” “so it needs to be”) with formal academic phrasing (e.g., “strict control… is required,” “necessitating disinfection”).

2.Structural Hierarchy: Added numbered/subheaded sections (e.g., “1. Definition…,” “2. Control…”) for logical clarity, aligning with academic writing conventions.

3.Precision: Specified technical terms (e.g., “total residual chlorine (TRC)”) with acronyms for consistency, and explicitly referenced the standard code (*GB 18466-2005*) with its full title for academic rigor.

4.Formality: Adjusted casual syntax (e.g., “the problem is that”) to objective statements (e.g., “the core question thus arises”) to suit scholarly tone.