Multifunctional adsorbent based on metal-organic framework modified bacterial cellulose/chitosan composite aerogel for high efficient removal of heavy metal ion and organic pollutant

A novel adsorbent based on zeolitic imidazolate framework-67 (ZIF-67, a sort of metal-organic framework) modified bacterial cellulose/chitosan (BC/CH) composite aerogel was prepared through a facile method combining physical mixture, in situ synthesis, and lyophilization. The water stability of CH aerogel was improved by incorporating BC nanofibers instead of using environmentally unfriendly chemical crosslinking agent. The loading rate of ZIF-67 was as high as 46.1% and the BET specific surface area of ZIF-67/BC/CH aerogel reached to 268.7 m2 g−1, which was much larger than that of BC/CH aerogel (8.4 m2 g−1). The as-prepared ZIF-67/BC/CH aerogel was employed to remove heavy metal ions and organic dye in aqueous solution. The adsorption capacities of the composite aerogel for Cu2+ and Cr6+ were 200.6 mg g−1 and 152.1 mg g−1, respectively. Moreover, the adsorption mechanism was investigated by X-ray photoelectron spectroscopy (XPS). Besides, the aerogel also showed almost 100% of removal rate toward active red X-3B through one time of adsorption. Consequently, the ZIF-67/BC/CH aerogel, as a novel and high efficient adsorbent, has a good application potential for wastewater treatment.