Arsenic contamination is a global environmental problem. Trivalent arsenic As(III) can be commonly found in nonferrous metal smelting wastewater, which is more toxic and challenging to remove compared to pentavalent arsenic As(V). Therefore, the key step in arsenic pollution control is to oxidize As(III) to As(V). Tooeleite (Fe6(AsO3)4(SO4)(OH)4·4H2O), the only known ferric arsenite sulfate-bearing mineral, exhibits the potential to directly remove and stabilize As(III) in wastewater. A novel chemical mineralization method was developed for the direct removal of As(III) based on the control of the precursor mineral phases. The mineral transformation processes involved the adsorption of arsenic onto ferrihydrite, then the amorphous tooeleite formation, and the rapid mineralization of amorphous precursors. Novel methods for enhancing tooeleite mineralization with carboxylic acid organics and seed crystal induction were proposed, and this breakthrough achieved the leaching content of arsenic in synthetic tooeleite below the standard limit of 5 mg/L for the first time. In addition, our research group has carried out studies on biomineralization. The effect of Acidithiobacillus ferrooxidans on the morphology evolution of mineral formation was elucidated, the arsenic-containing ferric sulfate was formed as a precursor and then the precursor was dissolved and recrystallized to tooeleite. Furthermore, a cocultivation system of Acidithiobacillus ferrooxidans and Acidiphilium acidophilum was established for biomineralization research. This cocultivation system has achieved a 45% improvement in the arsenic stabilization efficiency, with a minimum arsenic concentration required for mineralization as low as 200 mg/L. Biomineralization technique holds great promise as a green and ecological approach for arsenic stabilization.