The　aim　of　this　study　was　to　determine　an　appropriate　combination　for　effective　and　economical　COD　and　nitrogen　removal　from　landfill　leachate.　Biological　(nitrogen)　treatment　was　performed　with　the　autotrophic　nitrogen　removal　(ANR)　process.　The　(post-)　treatment　performances　of　(i)　ozonation　alone,　(ii)　adsorption　to　granular　activated　carbon　(GAC)　alone,　(iii)　the　combination　of　03　and　GAC　and　(iv)　an　integrated　approach　with　continuous　recirculation　of　ozonated　ANR　effluent　were　investigated.　It　was　observed　that　ANR　post-treatment　with　ozonation　was　able　to　remove　only　15.2%　of　residual　COD　and　14.0%　of　total　nitrogen　in　the　effluent　whereas　using　activated　carbon　a　73.6%　removal　efficiency　of　COD　and　17.3%　of　total　nitrogen　was　achieved.　The　best　performance　was　obtained　for　an　ANR　post-treatment　combination　of　ozonation　and　GAC,　ensuring　a　high　removal　for　both　COD　and　total　nitrogen.　When　different　ratios　of　zonated　effluent　were　mixed　with　the　influent　of　the　ANR,　it　was　found　to　be　possible　to　reach　COD　removal　as　high　as　40%　in　the　ANR　with　a　slightly　decrease　in　nitrogen　removal　of　around　70-80%　compared　to　respectively　5.31%　(COD)　and　85.9%　(total　nitrogen)　when　no　ozonated　leachate　was　recycled　to　the　ANR　reactor.　Taking　the　overall　performance　and　operational　expenses　into　account,　a　combination　of　ANR　biological　treatment　and　its　different　(post-)　treatments　(ANR　+　zonation　+　GAC)　results　in　a　good　performance　and　a　lower　cost　compared　to　traditional　treatment.　(C)　2015　Elsevier　B.V.　All　rights　reserved.