Arsenic polluted water is a global concern and puts millions of people at risk of developing cancer. The improvement of aqueous solution coexisting with arsenite and arsenate using iron mixed porous clay pellet was investigated in batch and fixed-bed column systems. Batch studies showed that the removal rate occurred into two main phases with the equilibrium time of 52 h. The pseudo-second-order model well described the experimental data. Isotherm data were well fitted by the Langmuir-Freundlich model. The removal efficiency was significantly reduced in the alkaline solution and the presence of phosphate ion. The column study revealed that the breakthrough time and saturation time increased with the lower feeding flow rate, higher bed height, and lower initial adsorbate concentration. The Thomas model provided a good performance for predicting the column experimental data.