The effects of metal elements on ramie fiber oxidation degumming and the potential of using spherical bacterial cellulose for metal removal

Current production of ramie fiber (the "queen" of nature fiber) requires the oxidation degumming process which suffers from the presence of metal elements due to the well-known Fenton reaction. In this study, the metal species/contents in current major degumming systems along Yangtze valley and their effects on the final ramie fiber properties (e.g. degree of polymerization (DP), tenacity, elongation) were assessed. The potential of employing our recently developed spherical bacterial cellulose (SBC) as recyclable metal adsorbent was also evaluated. Results showed that excessive amounts of metal elements (e.g. Ca, Mg, Fe, Mn, Cu, Pb) existed in the degumming systems which were detrimental to the final fiber properties. The application of 2,2,6,6-tetramethylpy-peridine-l-oxy radical (TEMPO)-oxidized spherical bacterial cellulose efficiently removed these metal elements and improved the degree of polymerization and tenacity of ramie fiber products. Our results could also open the door for the potential application of spherical bacterial cellulose as super absorbance in different types of waste water treatment. (C) 2018 Elsevier Ltd. All rights reserved.