Dr. Janaki R.R. Alavalapati, Dean
School of Forestry & Wildlife Sciences
3301 Forestry and Wildlife Building
602 Duncan Drive
Auburn, Alabama 36849-3418
Ph.D. Seminar: Diego Gomez Maldonado, Maj. Prof, Dr. Maria Soledad Peresin
Title: Development of bio-based systems as pollutants removal for water remediation
Location: Dixon Executive Conference Room, 3315
Date: Wednesday, March 31, 2021
Time: 8 a.m.
Cellulose nanofibril were used as scaffolds for the development of adsorbents for pollutants; in particular, the cyanotoxin microcystin-LR. The adsorbents were modified to capture the toxin with the inclusion of β-cyclodextrin. The first approach tested was the direct adsorption onto the surface of the fibrils and evaluated on thin films by Quartz Crystal Microbalance with Dissipation monitoring and in bulk by the generation aerogels from the modified fibrils which adsorption was followed by High-Pressure Liquid Chromatography. The adsorption occurred in both levels, with better results in surface level; interestingly the adsorption was limited by the density of crosslinking of the cyclodextrin and the salinity of the media carrying the microcystin.
The second approach was the generation of an active coating with oriented β-cyclodextrin immobilized on chitosan. The coating of nanocellulose fibers was done by the passive method of immersion of the material to coat into a solution with a strong ion presence. Moreover, the adsorption of the cyanotoxin was achieved on thin films as followed on the Quartz Crystal Microbalance. The coating was also tested on 3D structures generated by both typical approaches for nanostructured materials: nanocellulose beads from a bottom-up technique and delignified wood (nanowood) from a top-down. On the tested systems the successful coating was confirmed by different spectroscopic and chromatographic techniques. Furthermore, the adsorption of the toxin was successful only on the coated materials, demonstrating that the coating not only modified the surface area but also added the aimed activity to remove pollutants such as microcystin-LR.