We attempted catalytic wet air oxidation (CWAO) of nanofiltration (NF)-reject using Pd based catalyst viz., Pd/activated charcoal (AC) and PdCl2 with the objective of degradation of refractory organic pollutants. Refractory organic pollutants in NF-reject before and after WAO and CWAO were confirmed by GC-MS analysis. Experiments were conducted to investigate the effects of temperature, catalyst dosage and air partial pressure on the rate of removal of total organic carbon (TOC). The reaction kinetics can be conveniently described by considering two-stage first order kinetics. The use of Pd/AC afforded 85% TOC removal, the corresponding rate constant (k) was 2.90 +/- 0.075 x 10(-3) min(-1) (Pd/AC, 100 mg/L; T, 473.15 K; P-air, 0.69 MPa). On the other hand, 75% TOC was removed with k = 2.31 +/- 0.075 x 10(-3) min(-1) using Pd2+ catalyst (Pd2+, 16.66 mg/L; T, 473.15 K; P-air, 0.69 MPa). The observed rate of mineralization under Pd-catalyzed conditions was significantly higher than that of the uncatalyzed oxidation (41%) under the similar experimental conditions. Catalyst stability experiments were performed and TEM, SEM, XRD, Raman and XPS characterization data collected. Despite some morphological transformation of support, Pd catalyst was stable under CWAO conditions. (C) 2013 Elsevier B.V. All rights reserved.