Arsenate (As(V)) oxyanion removal was achieved utilizing diverse chitosan-containing adsorbents, such as chitosan beads, protonated chitosan flakes, chitosan powder, and chitosan functionalized with meso-2,3-dimercapto succinic acid (DMSA), and glutaraldehyde (GLA). Protonated Chitosan Flakes (PCF) showed to be the more effective adsorbent for the removal of As(V) oxyanion from aqueous solutions, removing 97% at the initial concentration of 0.500 mg/L. As(V) adsorption was favored by the Langmuir model, with a maximum adsorption capacity (Q°) of 5.43 mg/g. The results showed that the PCF is an excellent non-toxic and inexpensive adsorbent for As (V) oxyanion removal in level traces from aqueous solution.