Adsorption behavior and mechanism of Lead (Pb) by sulfate polysaccharide from Enteromorpha prolifera.

Lead (Pb) pollution poses severe healthy and ecological risks to humans. In this work, sulfate polysaccharide from Enteromorpha prolifera (SPE) was utilized for Pb adsorption from simulated intestinal fluid. In order to evaluate its adsorption behaviors comprehensively, batch adsorption of Pb was investigated under different conditions. Results showed that SPE presents high adsorption ability for Pb through chemical adsorption process and the maximum adsorption capacity for Pb was 278.5 mg/g. And SPE exhibited higher removal efficiency (≥60%) for trace Pb (<10 mg/L) compared to that of other adsorbents based on polysaccharide. Besides, its adsorption can be described by Langmuir isotherm and pseudo-second-order kinetic models. Further, XRD, FTIR, and XPS were used to characterize the possible interaction of Pb with SPE, and the results showed that carboxyl and hydroxyl groups in SPE play more important role than that of sulfate group. Our work represents the first assessment of Pb adsorption properties of SPE. This investigation highlights the potential application of SPE to protect the body from hazard of food-derived heavy metals.