Removal of Arsenic from Kelp Polysaccharide by MIL-88A Functionalized Polyurethane

This work focused on the problem of high arsenic (As) residues in kelp polysaccharides and develops an effective method for removing As from kelp polysaccharides. Lavoisier Frameworks material (MIL-88A) was assembled with Polyurethane foam (PU). Scanning electron microscopy (SEM), Fourier infrared spectroscopy (FTIR), and X-ray diffraction spectroscopy (XRD) were used to characterize the morphology and surface functional group of MIL-88A/PU materials, and then atomic fluorescence spectroscopy (AFS) was used to investigate the ability of MIL-88A/PU to remove As. Results showed that MIL-88A was successfully loaded on PU, and the MIL-88A/PU possesses abundant active sites. The maximum adsorption capacity for As (III) was 107.52 mg/g when the absorption conditions maintained at 298 K, pH5.0, and 240 min. After treating by MIL-88A/PU, the amount of As in kelp polysaccharides were effectively reduced, and the removal rate of total As and inorganic As was 70.43% and 73.33%, respectively. Moreover, the preservation rates of polysaccharide and protein content in kelp polysaccharides were 90.47% and 73.76%, respectively. Remarkably, dealing kelp polysaccharides with MIL-88A/PU significantly reduced the amount of As, which would improve the economic benefit of the kelp polysaccharides.