Filter design for arsenic species in aqueous environments: An ab initio optimization of the absorbing capacity of magnetite-based arsenic filters

•Optimization of magnetite nanoparticle’s adsorption capacity in the DFT framework.•Arsenic filter design arousing from DFT-based optimized adsorption properties.•Mathematical models of collective adsorption in a macroscopic filter. Polluted water sources are a public health issue causing concerns in regions with a low-quality water treatment system. Gastrointestinal diseases, skin associated illness, and even skin cancer development commonly link to prolonged intakes of arsenic compounds. Thus, we propose the design of a low-cost, eco-friendly arsenic filter using a magnetite-based adsorbent. Density functional theory calculations warrant the optimal adsorbing capacity in the filter design with magnetite nanoparticles (Mag-NPs) capturing up to 5 arsenic species diluted in aqueous environments. A lineal and a geometric model describe the collective adsorbing mechanism of the Mag-NPs for determining the filter’s dimensions. Finally, our filter design framework is applied using the water source conditions of the Toacaso community in Ecuador.