Study on the control of emerging nitrogenous disinfection by-products and precursors by biological and advanced treatment for wastewater reclamation

The control of typical nitrogenous disinfection by-products (N-DBPs, including nitrosamines, haloacetonitriles and trichloronitromethane) is a major concern in wastewater reuse. In this study, the presence levels of N-DBPs in the influent and effluent of biochemical treatment in wastewater treatment plants (WWTPs) with different biological treatment processes were analyzed. The secondary effluent of one of the WWTPs was selected to investigate the removal of N-DBPs and their precursors in different advanced treatments (powdered activated carbon adsorption, ozone oxidation, ferrate oxidation, and chlorine dioxide oxidation). The results showed that the biological treatment process resulted in the generation of nitrosamines. For the advanced treatment processes, powdered activated carbon (PAC) catalyzed the generation of nitrosamines, while ozone oxidation formed nitrosamines directly. The selected advanced treatment processes showed different degrees of removal of nitrosamine precursors, with PAC and chlorine dioxide providing better control of N-nitrosodimethylamine and total nitrosamines. However, the oxidation processes had mixed effects on the precursors of haloacetonitriles (HANs) and trichloronitromethane (TCNM). Ferrate (FeVI) showed significant removal of precursors of both HANs and TCNM, while chlorine dioxide increased the formation of HANs in the effluent treated with low concentration of chloramine. Ozonation increased the generation of TCNM during post-chloramination. The results promote the development of advanced wastewater treatment technologies and provide theoretical guidance for related research.

Automated summary

This study analyzed the control of N-DBPs in wastewater reuse and investigated the removal of N-DBPs and their precursors by different biological and advanced treatment processes. Results showed that different treatment processes had varying effects on N-DBPs, with powdered activated carbon and chlorine dioxide providing better control of N-DBPs.