High efficient As(III) removal by self-assembled zinc oxide micro-tubes synthesized by a simple precipitation process

Zinc oxide (ZnO) micro-tubes via self-assembly of nanoparticles were synthesized by a simple precipitation process. Removal of As(III) (arsenite) from water by ZnO micro-tubes through adsorption was investigated with both lab-prepared and natural water samples. The result showed that these self-assembled ZnO micro-tubes are effective to remove As(III) from both lab-prepared and natural water samples at near neutral pH environment. These ZnO micro-tubes have a high adsorption capability on As(III) at low As(III) concentration. When the equilibrium As(III) concentration was around 0.1 mg/L, the amount of As(III) adsorbed at equilibrium was over 10 mg/g. At high equilibrium concentration, the adsorption capacity of these ZnO micro-tubes on As(III) reached over 39.4 mg/g. These ZnO micro-tubes could provide a simple single-step treatment option to treat arsenic-contaminated natural water, which requires no pre-treatment or post-treatment pH adjustment for current industrial practice.