Chlorine is widely used across India for disinfecting drinking water. However, studies show that chlorine-based treatment can lead to the formation of several harmful disinfection byproducts. Globally, more than 700 such by-products have been identified, with the United States Environmental Protection Agency classifying the major ones as Trihalomethanes (THMs) and Haloacetic Acids (HAAs).

According to the Central Pollution Control Board (CPCB), nearly 82.7 per cent of water treatment plants in India use chlorine gas for sedimentation, filtration and disinfection, and others rely on bleaching powder or liquid chlorine. Chlorine usage beyond the prescribed limit of 0.2 mg per litre can pose health risks.

Professor Dr Kanmani, head of the Civil Engineering Department at Anna University, told DT Next that the oxidation processes use strong oxidants to remove both organic and inorganic contaminants by breaking them down into less harmful compounds. The methods include ozonation (O₃), ultraviolet (UV) radiation and hydrogen peroxide treatment.

A detailed study conducted by the university demonstrated that oxidation-based treatment significantly reduces the formation of harmful by-products while ensuring effective microbial disinfection. Researchers emphasised that this method is suitable for integration into larger municipal water treatment plants and overhead storage systems.

The university believes that adopting the oxidation-based treatment technologies could strengthen public health safeguard systems and ensure safer drinking water supply systems across urban and rural areas, as millions are affected annually in India by unsafe drinking water.