Four samples of ceria incorporated manganese oxide (NCMO) were prepared by co-precipitation-calcinations and sol-gel methods, and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy. BET surface area etc. The synthetic samples were nanoparticle agglomerates with irregular surface morphology (Ce:Mn = 1:1). The NCMO-1b sample, prepared by the calcination of metal hydroxide at 573 K for 3.0 h, was a nano-crystalline (70-90 nm) and hydrated material having high BET surface area (116.96 m(2) g(-1)). The arsenic(V)-sorption by the samples at pH 7.0 (+/- 0.2) and 30 degrees C showed that the NCMO-1b is a most efficient material. Optimum pH range for the arsenic(V) sorption is 3.0-7.0 at 303 (+/- 1.0) K. Kinetics and equilibrium data obtained (pH = 7.0 +/- 0.2, T= 303 +/- 1.0 K and I = 0.01 M) had described the pseudo-second order kinetics and the Freundlich isotherm models well, respectively. Thermodynamics of the sorption reaction showed that the changes of enthalpy (Delta H degrees), entropy (Delta S degrees) and Gibbs free energy (Delta G degrees), respectively, were +23.901 kJ mol(-1), +0.175 kJ mol(-1) K-1 and -25.737 to 32.753 kJ mol(-1) at T = 283-323 K. Estimation of the sorption energy (E = 17.15 kJ mol(-1)) indicated that the arsenic(V) was chemisorbed on NCMO-1b. The phosphate only reduced the arsenic(V) removal efficiency of NCMO-1b. (C) 2011 Elsevier B.V. All rights reserved.