Chlorine-based disinfectants are used to disinfect wastewater, so why is total residual chlorine included in the monitoring items for medical wastewater? Once you understand the harm that residual chlorine in water poses to human health, this question will no longer be confusing.

As the saying goes, “Every medicine has its side effects.” Although this analogy is not perfect—since disinfectants are not medicines taken by humans—the logic is similar. Disinfectants can eliminate pollutants in wastewater, but only when used in appropriate amounts. Excessive levels are harmful to the human body. Where does this harm come from? Let’s take a look at the health risks of residual chlorine in water.

When residual chlorine in water reacts with organic acids, it produces many carcinogenic byproducts, such as chloroform. Furthermore, excessively high total residual chlorine itself is harmful to humans and produces a strong, unbearable odor. These toxic substances do not only enter the body through ingestion; they can also be absorbed through the skin, seriously endangering human health. This is the key reason why monitoring total residual chlorine in water is essential: to ensure that residual chlorine levels do not exceed standards during disinfection.

Total residual chlorine mainly includes free chlorine and combined chlorine in water, and compliance with discharge standards is achieved through dechlorination treatment.

How do we confirm that total residual chlorine in wastewater meets the standard? This requires real-time monitoring using the Hangzhou Modi RCl900 Online Total Residual Chlorine Analyzer. The measured data are then used to evaluate whether the residual chlorine concentration complies with regulatory limits. The same principle applies to other water quality parameters: proper treatment and monitoring must be carried out, and water quality is judged based on objective data.