Evaluation of the adsorption capacity of glyphosate in a microbial cellulose composite

Abstract

The objective of this project was to develop a composite based on microbial cellulose (CM), chitosan (Qs) and citric acid (AC) as a crosslinker at two different concentrations (4 and 6% w/v). The CM was obtained from the fermentation of fruit residues with a SCOBY (symbiotic consortium of bacteria and yeast). The composites were morphologically characterized by SEM and spectroscopy techniques (FTIR-ATR) as well as UV-VIS spectrophotometry with ninhydrin were used to evaluate the composite as an adsorbent for glyphosate in water; in the spectra obtained by FTIR, the representative vibrational bands of the functional groups belonging to chitosan and microbial cellulose were observed; for cellulose and chitosan composites with 4% citric acid in 1579 cm-1 , 1386 cm-1 , 1046 cm-1 and 853 cm-1 ; and for the 6% cellulose-chitosan-citric acid composite at 1573 cm-1 , 1380 cm-1 , 1056 cm-1 and 503 cm-1 , thus attributing cross linkage between the biopolymers. Post- adsorption FTIR-ATR analysis revealed significant changes possibly attributable to the adsorption of glyphosate in the cellulose composites. Further research is still being conducted to better understand this interaction and the involved mechanism; the goal is to comprehend how microbial cellulose can effectively adsorb glyphosate, which could have practical and efficient applications in the remediation of environments contaminated with this herbicide.