Disinfectants In Water

Disinfectants in water play a crucial role in ensuring that drinking water is safe for consumption by killing or inactivating harmful microorganism that can cause diseases. Disinfection is a key step in the water treatment processes with the purpose of disinfection being to protect public health by reducing or eliminating harmful microorganisms, such as bacteria, viruses, and protozoa, that may be present in the water, which can cause waterborne diseases if consumed. There are several disinfectants used in water treatment, including, chlorine, which is one of the most commonly used disinfectant being effective against a wide range of microorganisms, chloramine which is formed by combining chlorine with ammonia, providing a longer lasting disinfectant. Ozone is also a known powerful oxidizing agent and disinfectant, which is effective at inactivating microorganisms and breaking down organic and inorganic contaminants. UV (Ultraviolet) Light is regularly used for disinfection by exposing water to UV radiation, which damages the genetic material of microorganism, rendering them unable to reproduce and Oxygen-Based disinfectants such as hydrogen peroxide and peracetic acid.

When disinfectants react with naturally occurring organic matter in water, they can form disinfectant byproducts (DPBs) such as trihalomethanes (THMs) and haloacetic acids (HAAs), which may have health concerns. To ensure the water remains protected from microbial contamination as it travels through the distribution system to consumers, a residual disinfectant if often maintained, which is carefully monitored to meet regulatory standards and guidelines. In many systems, chlorine is added for disinfection but is then removed or reduced through dichlorination processes to prevent taste and odour issues, minimising DBP formation. Effective disinfection requires a specific contact time between the disinfectant and microorganisms, this ensures that a sufficient concentration of the disinfectant interacts with the pathogens. Water treatment facilities regularly monitor disinfectants levels and water quality to ensure compliance with regulatory standards and to maintain safe drinking water, with water utilities being required to inform the public about the use of disinfectant and any changes in disinfection practices.