Effluent loads from different traditional and emerging ECF bleaching sequences were investigated. Oxygen delignified Eucalyptus camaldulensis and Acacia mangium kraft pulps having similar kappa number, ca 12.0 were used in this study. Different ECF bleaching sequences were compared with reference sequence, D 0 EopD 1 in terms of effluent load, such as AOX, COD and TOC. Depending on the nature of sequences 6.0 to 63.0% chlorine dioxide consumption was reduced and as a result the amount of AOX formation was also reduced. The effluent from sequences (DZ)EopD 1, DHTEopD1, AhotD0EopD1, Ahot(DZ)EopD1 and ZEopD1 showed marginally higher COD and TOC in comparison with reference sequence, D 0 EopD 1 . Sequences like, D 0 EopQ(PO) and (DZ)EopQ(PO) having (PO) instead D 1 of reference sequence reduced AOX in effluent substantially; but COD and TOC loads were increased. In all cases acacia gave marginally higher effluent loads compared to eucalyptus.