ABSTRACT
Conventional drinking water disinfectants such as chlorine and other chemical oxidants have successfully protected public health against waterborne microbial diseases for decades since ensuring the microbiological safety of drinking water is of paramount importance worldwide. This has been elaborately described in Chapter 2. However, chemical disinfection has several demerits, including the production of potentially toxic by-products, problems of taste and odour, and resistance of certain emerging pathogens such as Giardia and Cryptosporidium species, to name a few. This has led to a reappraisal of traditional chemical disinfection practice. Effects of climate change leading to natural disasters like ood and drought could exacerbate these concerns, which could make treatment more challenging. In the longer term, the pressure on the chemical industry to reduce production of chlorine and chlorine-based disinfectants for environmental reasons (greener routes) may force water companies to turn to other disinfectants or employ nonchemical disinfection processes.
