Hospitals are living facilities as well, which inevitably generates domestic sewage. While Monitoring of Medical Wastewater is the priority for hospitals, is it necessary for hospitals to treat and monitor domestic sewage? This article gives a brief overview.

Given the complex conditions in hospitals, medical wastewater and domestic sewage feature different water qualities. Ideally, they should be collected and treated separately before being discharged into urban sewage treatment plants or natural water‑bodies. However, separate collection is often difficult to achieve in hospital premises. In accordance with the Discharge Standard of Water Pollutants for Medical Institutions, the following scenarios apply:

1. Sewage from infectious‑disease wards shall be collected independently and disinfected prior to mixing with other wastewater.
2. Separate collection is preferred for non‑infectious medical wastewater and domestic sewage. Where separate collection is not feasible due to on‑site constraints, the combined wastewater shall be treated as medical wastewater.
3. Separate collection is mainly intended to reduce treatment loads. The primary difference between hospital domestic sewage and medical wastewater lies in pathogen content. After disinfection, the two streams show little difference, with relatively low pollutant concentrations for easier treatment.

Three key points shall be noted for medical wastewater in compliance with GB 18466‑2005:

1. For general hospitals with infectious‑disease wards, wastewater from infectious‑disease wards shall be separated from that of non‑infectious wards. Wastewater and faecal waste from infectious‑disease wards must undergo disinfection before mixing with other wastewater for further treatment.
2. Solid infectious waste and various chemical waste liquids shall not be discarded or poured into sewers.
3. Domestic sewage requires monitoring. Monitoring locations and approaches shall be determined based on actual conditions. If on‑site conditions prevent separate collection of medical wastewater and domestic sewage, the mixed flow shall be handled as medical wastewater.

Most hospitals adopt chlorine‑based disinfection. Real‑time monitoring of total residual chlorine is therefore required during medical wastewater monitoring to regulate chlorine dosage and prevent hazards caused by excessive total residual chlorine. The RCl900 Online Total Residual Chlorine Analyser can be applied for such monitoring.