Ozone-biological activated carbon integrated treatment for removal of precursors of halogenated nitrogenous disinfection by-products

► Conventional process is ineffective in removal of the precursors of TCNM and DCAcAm, two N-DBPs. ► Ozonation improved the performance of BAC on removal of DON and precursors of halogenated N-DBPs. ► Ozonation somewhat reduced the precursors of CF, DCAN and DCAcAm, but increased the TCNM formation. ► O3-BAC process is a promising advanced treatment technology in control of halogenated DBPs.