Chitosan was extracted from squid pen (Dosidicus gigas) by cold homogeneous deacetyla-tion process and characterized by FT-IR, SEM. Chitosan iron nanoparticles (Ch:nZVI:Ch) was prepared by reducing Fe+3with NaBH4in the presence of chitosan as stabilizer. The images by SEM show that the area of chitosan beads are highly porous and zero-valent iron is loaded correctly and efficiently dispersed. To evaluate the efficiency of removal 100 mg of synthesized material was taken to remove As from 1000 μg/L to < 10 μg/L in 120 minutes. When the material is saturated, the regeneration of the adsorption was carried out using 0.1 M NaOH. Results obtained from batch studies of groundwater and surface water contaminated by arsenic obtained from Tacna—Perú, were reduced from 500 μg/L to < 10 μg/L. In conclusion, ions present in both groundwater and surface water do not interfere with the removal of As in drinking water sources.