**4. Conclusion**

We have successfully fabricated the poly Schiff base-coated bacteria cellulose without the conventional dispersion treatment of the cellulose aerogel. The key is to pretreat the bacteria cellulose with sodium silicate to exfoliate the nanofibers from the big bundles of raw cellulose fibers. Due to the intact texture of the pretreated bacteria cellulose, the composite aerogel is of good properties (e.g., mechanical and thermal) and high mass transfer efficiency. The adsorption capacity of the aerogel is 321.5 (Cr(VI)), 256.4 (Cu(II)), 153.8 (Re(VII)), 333.3 (Conga red), and 370.3 (Orange G) mg g<sup>−</sup>1. The adsorption process obeys the pseudo-second order kinetic. The adsorbent can be regenerated easily and used to remove the pollutants without obvious performance attenuation.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2073-4360/12/3/714/s1, 1. Detail of Fabrication, 2. Photograph of pBC-Polym-0.04 and BC-Polym-0.04, 3. The morphology of pBC-Polym-0.02 and pBC-Polym-0.08, 4. Specific surface area and porosity, 5. Thermal stability, 7. Adsorption mechanism, 8. Other pollutants

**Author Contributions:** Conceptualization, L.R. and L.Z.; methodology, L.R.; software, L.R.; validation, Z.Y., and H.W.; formal analysis, L.R; investigation, L.H.; resources, Y.H.; data curation, L.H.; writing—original draft preparation, L.R.; writing—review and editing, L.Z.; visualization, Z.Y.; supervision, H.W.; project administration, Z.Y.; funding acquisition, H.W. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was funded by National Key R&D Program of China (2016YFC0403003) and Key R&D Program of Hunan Province (2018SK2026 and 2018SK2043). The authors all declare that they have no conflict of interest.

**Acknowledgments:** Haiying and Liyuan thank the financial support by Key R&D Program of Hunan Province (2018SK2026 and 2018SK2043) and National Key R&D Program of China (2016YFC0403003).

**Conflicts of Interest:** The authors all declare that they have no conflict of interest.
