Adsorption of natural composite sandwich-like nanofibrous mats for heavy metals in aquatic environment

Natural polymer cellulose acetate (CA) and natural rectorite (REC) were employed to fabricate nanofibrous mats and then immobilized with biosorbent s accharomyces cerevisiae ( SCV ) to construct a sandwich-like structure. The hydroxyl and carbonyl groups in the CA endowed the nanofibrous mats with a strong affinity for removing heavy metals, allowing them to act as an adsorbent for heavy metals. The REC, which was blended with CA to fabricate the CA/REC nanofibrous mats, increased the specific surface area of the nanofibers and provided ideal scaffolds for the attachment of SCV , resulting in more contact reactions between the nanofibrous mats and heavy metal ions . The adsorption equilibrium was reached within 30 min at the optimum pH of 7, and the saturated adsorption capacities of Zn (II) and Cd (II) were 104.31 and 99.33 mg/g, respectively. The adsorption for Zn (II) and Cd (II) decreased to 47.44 and 62.11 mg/g in the co-system, but the total amount of adsorption (111.36 mg/g) was remarkably higher than that for the single system, indicating that the all-natural composite mats had great potential to simultaneously adsorb multiple heavy metals. After three cycles adsorption-desorption, the composite mats maintained a high adsorption efficiency.