Various Disinfection Processes and Formation of Disinfection by-Products in Drinking Water

The increase in the urban population means that water consumption is increasing. In this way, several methods to produce drinking water have been used, such as chlorination, UV radiation, and ozonation. However, chemical reactions between disinfection methods and the different organic matter that are found in surface and groundwater lead to the formation of disinfection by-products. These by-products can, many times, present toxic and/or carcinogenic potential and have aroused the interest of researchers regarding their characterization, composition, and quantification. Some factors may favor the appearance of disinfection by-products, mainly due to the application of chlorine to eliminate bacteria, viruses, molds, and yeasts. In addition, the type of organic matter, pH of the water, level of residual chlorine, contact time, temperature, and the presence of bromine and iodine ions in the water can affect the formation of chemicals. The main by-products found in drinking water are Trihalomethanes, Halobenzoquinones, Haloketones, Haloacetic acids, and Nitrosamines. Human contamination by disinfection by-products can occur through ingestion of drinking water and through the skin while bathing or diving in chlorinated pools. This chapter addresses the different disinfection processes, their strengths, and weaknesses, as well as the characterization of the main disinfection by-products and their potential risk to human health.