Cellulose-Supported Nanosized Zinc Oxide: Highly Efficient Bionanomaterial for Removal of Arsenic from Water
Sunil K. Sharma, Priyanka R. Sharma, Hui Chen, Ken I. Johnson, Chengbo Zhan, Ruifu Wang, Benjamin S. Hsiao
Abstract
Arsenic contamination in drinking water has become a worldwide problem, especially in developing countries, and has led to the development of various arsenic removal methods. Herein, regenerated microfibrillated cellulose (R-MFC) fibers were isolated by a combination of dissolution and regeneration methodologies using a mixture of phosphoric acid and ethanol treatment on jute cellulose. The isolated R-MFC fibers possessed high specific surface area (10 m2/g), good aspect ratio (L/D = 30), high thermal stability (T max = 352 °C) with a zeta potential of −8.4 mV, and a low crystallinity index of 47.5%. These R-MFC fibers exist in cellulose II polymorph form, confirmed by 13C CPMAS nuclear magnetic resonance and wide-angle X-ray diffraction studies, and they were highly effective as support for growth of ZnO nanocrystals. Wide-angle X-ray diffraction and transmission electron microscopy analysis on the imbedded ZnO nanocrystals indicated that they possessed the hexagonal wurtzite crystal structure. The R-MFC composite loaded with 41 wt% of ZnO nanocrystals was found to be highly efficient in removing arsenic ions from contaminated water, with a maximum capacity of 4,421 mg/g at neutral pH, which is significantly higher than the various absorbents for arsenic removal reported in the literature.