Ozonation is a common treatment process used for bacteria
disinfection and organic pollutant oxidation in drinking water
treatment [37] based on the use of active ozone gas (O3). Based on
Table 2, it is reported that the autotrophic nitrogen removal (ANR)
process with ozonation–adsorption (activated carbon) hybrid
system has successfully removed 82.6% of COD and 78.4% of TN in
landfill leachate. In comparison with ANR stand-alone system, the
removal is much lower compared to hybrid system where the
removal of COD and total nitrogen is achieved is only 13.2% and 74%, respectively Schematic diagram of an autotrophic
nitrogen removal (ANR) process with ozonation–adsorption
(activated carbon) hybrid system is as shown in Fig. 3b.