The present study shows arsenic removal and bactericidal efficiency of sodium ferrate with various adsorbents to decontaminate water. Among the tested adsorbents, the ash of Unio (Lamellidens marginalis) shells was found to be the best. It reduces 500 ppm arsenic in water to <10 ppb in 40 min by adsorption. As(III) was converted into As(V) by in situ prepared Na2FeO4, which was then removed by adsorption on to the ash of Unio. Bactericidal potential of sodium ferrate for the bacterium E. coil was found better than those of three antibiotics viz. moropenum, vancomycin, and piperacillin tozabactum, and it was found at par with ampicilin. Bactericidal effect was found due to the leakage of protein from the cell wall. Effects of different process variables on the extent of removal of As(V) were studied. Composition of ash and morphological changes after adsorption were determined with Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) studies.