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Bacterial cellulose (BC) is a green biopolymer suitable for heavy metal ion removal from aqueous solution due to its nano-porous microstructure. Polyethyleneimine-bacterial cellulose (PEI-BC) was prepared by reductive amination of dialdehyde BC with polyethyleneimine. The capacity of PEI-BC in Cu(II) and Pb(II) adsorption from aqueous solution was investigated. The adsorption kinetics could be well expressed by pseudo-second-order model and the adsorption isotherm data were well fitted with Freundlich model. Adsorption processes of Cu(II) and Pb(II) by PEI-BC reached equilibrium very rapid in 30 and 60 min, respectively. The maximum adsorption capacity of PEI-BC on Cu(II) and Pb(II) was found to be 148 and 141 mg/g, respectively, which was higher than that of unmodified BC and other modified BC reported. PEI-BC also showed good reusability in the adsorption of Cu(II) and Pb(II). This study demonstrates that polyethyleneimine modification makes BC a potential bioadsorbent for heavy metal ion removal in waste water. [ABSTRACT FROM AUTHOR]

Super adsorbents exhibit great potential to remove pollutants from media or store considerable amounts of water, which may undermine the pressure triggered by environmental pollution and shortage of water resources. Super adsorbents made from biopolymers have been an attractive topic because of biodegradability, renewability and outstanding adsorption capacity. Hemicelluloses are a type of biopolymers very abundant in agricultural, forestry and pulping industrial wastes. Hemicellulose-based bio-adsorbents are thriving because the inherent chemical structures and physical properties of hemicelluloses make themselves easy to be processed into matrix materials applicable in super adsorbents. This review summarizes recent studies in hemicellulose-based bio-adsorbents, i.e. hydrogels and activated carbons, from the perspectives of types, applications, fabrication methods, the elements affecting the adsorption performance and the kinetics of adsorption process, which thus helps to further improve the properties of hemicellulose-based bio-adsorbents and to promote the industrial production and utilization of hemicelluloses and hemicellulose-based bio-adsorbents. [ABSTRACT FROM AUTHOR]