Progress 06/01/21 to 07/14/22
Outputs
Target Audience:The research will focus on a broad audience including academic communities, university graduate and undergraduate students, and K-12 students through practical workshops, waste water facilities, and forestry bioproduct industries. Changes/Problems:Due to the PI's job transferring from the previous institution (University of Florida) to Georgia Institute of Technology, all the future work will be conducted in new institution. What opportunities for training and professional development has the project provided?The research conducted for this project contributes to the training of 2 Ph.D. students who have an exciting opportunity to be involved in interdisciplinary research including wastewater treatment, biowaste conversion, sustainable material/membrane synthesis, polymer grafting. PI Tong's group will mainly focus on the manipulating the molecular structure of amphiphilic bio-based polymer ligand (Cellulose, lignin or chitason based) ; 2. PI Chen will mainly focus on the fabrication and characterization of biocomposite ACMs to improve ACM performance. How have the results been disseminated to communities of interest?The research will be disseminated to academic communities, K-12 students through conference posters, workshops, and minority summer programs. What do you plan to do during the next reporting period to accomplish the goals?This report is used for the transferring purpose. Other future work will be conducted in PI'snew institution and co-PI's newsubawardee.
Impacts
What was accomplished under these goals?
Objective 1: Improve heavy metal binding affinity by manipulating the molecular structure of amphiphilic lignin-based polymer ligands; An anionic lignin-core dendritic biopolymer ligand with highly active and abundant ethylenediaminetetraacetic acid (EDTA) end groups was successfully synthesized. lignosulfonate was grafted with the epoxy group and reacted with the diamine to form NH2-terminated lignin. A lignin-based EDTA analogue was synthesized from amine-terminated lignin (LA) via a hydroamination followed by an acidification reaction. The metal-complex formation mechanism between biopolymer ligands with metals in an aqueous solution were elucidated. The successful grafting of EDTA termination structure on a crosslinking and amphiphilic lignosulfonate core could significantly improve metal complexation capability. The EDTA analogue as a bio-chelator provides a much higher affinity (kd =16.7 mM) to the divalent metal than LA and the pristine lignin. The SEM-EDS and TEM with the SAED analysis prove the successful formation of a multiple crystal lattice structure trapping copper molecules. Objective 2. Fabricate and characterize high-porosity biocomposite ACMs from cellulose acetate and lignin-based polymer ligands; we have used a regenerated cellulose support membrane coated with stable and covalent-bonded polyelectrolyte active layers synthesized by a reactive layer-by-layer (LBL) assembly method. We have tested the assembled LBL layers have been using scanning electron microscopy, Fourier-transform infrared spectroscopy and X-ray photo-electron spectroscopy. We have found that the covalent bonding provides the membrane with long-term stability and a tunable water flux compared to a membrane assembled by electrostatic bonding. The maximum adsorption capacity of the membrane active layers can reach up to 194 mg/g, showing more efficient adsorption at lower heavy metal concentration and higher pH value of feed solution.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
1. Meng, S., Z. Tong, S. Zhang, G, Li, H. Bao, S. D. Bruner, Y.C. Li, Y. Chen, Biowaste-derived, hyperbranched Dendritic EDTA analogue as anionic bio-chelator with superior metal affinity, ACS Sustainable Chemistry and Engineering, 2022. 10(6), 2010-2021.
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