The presence of arsenic in groundwater and other drinking water sources presents a notable public health concern. The utilization of iron-oxide nanomaterials as arsenic adsorbents has shown promising results both in laboratory and field conditions. This study focuses on characterizing the performance of nanoparticles prepared by different synthetic methods and with different surface coatings in arsenic removal. Poly (acrylic acid), polyethylene glycol, polyethylenimine were used to stabilize iron-oxide nanoparticles prepared by thermal decomposition to an aqueous solution. The effect that each polymer has on the materials was evaluated in batch and PEG was found to provide the best performance. To implement the nanoparticles in the field, a continuous flow column study was carried out by depositing the nanoparticles in poly(methyl methacrylate) (PMMA) beads. Even when the surface coatings are required to prevent nanoparticles from agglomerating, further efforts to deposit nanoparticles on a supporting material are required.