Formation of nitrogenous disinfection by-products (N-DBPs) in drinking water: emerging concerns and current issue

Nitrogenous disinfection by-product (N-DBPs) has always been one of the most concerned disinfection by-products (DBPs) in recent years. The toxicity of regulated DBPs is generally less than that of N-DBPs, which have been widely detected in finished drinking water. Despite the fact that N-DBPs are highly toxic, there are currently no N-DBPS species officially regulated by governments around the world. This paper provides a review of the formation mechanism and precursors of nitrogen-containing disinfection by-products in drinking water treatment. Also, the spcieces and inducing factors of N-DBPs were summarized. The data were mainly collected from 2000-2002 and 2006-2007 US Survey in effluents of US WTPs. Because nitrogen source is a prerequisite for the formation of nitrogen-DBP in drinking water, the occurrence of N-DBPS may increase due to the influence of sewage and algae blooms on water sources. Chloramine disinfection are used in most of developed countries for preferred secondary disinfection to reduce the formation of chlorine-related by-products, but this increases the formation potential of N-DBPs. Furthermore, the safety control of N-DBPs and suggestions for the further exploration of for efficient drinking water are discussed. Coagulation and filtration are not very effective in removing precursors (such as amino acids) of N-DBPs and the precursors need to be removed before disinfection.