Preparation of Freeze-Dried Porous Chitosan Microspheres for the Removal of Hexavalent Chromium

• DOI: 10.3390/app11094217
• Publication Date: 2021-05-06T15:10:27Z
• Authors: Wei Song; Jian Xu; Lepeng Gao; Qingzhu Zhang; Jin Tong; Lili Ren
• Keywords: Hexavalent Chromium

Novel porous chitosan microspheres were successfully produced by a freezing–lyophilization drying method in this study and then used as adsorbents to remove toxic iron metal, hexavalent chromium (Cr(VI)). The effects of the concentration solution, syringe diameter, freezing time on morphologies characterized. metal ion adsorption for Cr(VI) was also studied. Results showed that hydrogel beads at temperature −20 °C subsequently lyophilizing frozen structure allowed easily obtain with rough surfaces large pores, which more suitable materials ions. A solution 3% (w/v) diameter 500 μm have good sphericity, thinner pore walls, small sizes. capacity increased increase time. pH initial ranged from 3.0 5.0 beneficial maximum efficiency Cr(VI). prepared 72 h had higher 945.2 mg/g than those 24-h 48-h times. Kinetic process could be described pseudo-second order (PSO) kinetic model. equilibrium rate constant amount an time, 72-h 1.83 × 10−5 g mg−1 min−1 1070.5 mg g−1, respectively. potential facilitate separation recycling expensive wastewater.