Assessment of Caribbean Sargassum species for nanocellulose foams production: An effective and environmentally friendly material to water-emerging pollutants removal

In the present work, three species of sargassum from the coast of Quintana Roo, Mexico, were used (Sargassum fluitans III, Sargassum natans I, and Sargassum natans VIII) to extract sargassum-derived nanocellulose (SNC). It should be noted that using sargassum as a source of cellulose has been studied little compared to other sources to extract this polysaccharide. Two methodologies were evaluated and compared to optimize the nanocellulose isolation process from sargassum biomass. Nanocellulose foams were obtained and characterized by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR), which allowed us to identify the chemical structure of the samples. In addition, the crystallinity index of nanocellulose was calculated by X-ray diffraction (XRD). The morphologies of the samples were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which confirmed that nanofibers were obtained. Furthermore, the ability of nanocellulose to remove emerging pollutants in water samples was analyzed. Specifically, an antibiotic (ciprofloxacin), a surfactant (triton X-100), and a pesticide (glyphosate) were evaluated. According to the results, the maximum removal capacities of these foams to adsorb the emerging pollutants were 18.06, 74.68, and 28.07 mg*g(-1) for ciprofloxacin, glyphosate, and triton X-100, respectively. Those have a competitive capacity compared with analogous materials found in the literature. In addition, the Sargassum nanocellulose foams exhibit a removal percentage higher than 95 % for four cycles, which makes it an excellent candidate for designing removal systems for different kinds of pollutants.