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The demand for energy‐efficient water treatment as well as the limitation in adsorption of existing membranes has motivated the pursuit of membranes that can break the selectivity‐permeability trade‐off and provide high selective adsorption for chemicals of interest. The membrane adsorbers have received a lot of attention for removing contaminants from aqueous solution due to combine both advantages of adsorption and membrane separation. Membrane adsorbers constructed by biopolymer with many functional groups are widely used in water purification, because the biopolymers are easily available from biomass materials in nature, degradable, and low‐cost. This paper summarizes the characteristics and important development direction of these types of biomass‐based membrane adsorption materials to adsorb organic/inorganic contaminants of water and analyzes the preparation methods of natural biomacromolecule cellulose, chitosan, sodium alginate, and protein to construct the membrane adsorption materials, as well as the application of pollutant removal from aqueous solutions. According to the current problems and shortcomings in the research of biopolymer‐based membrane adsorbers, it is proposed to improve the understanding of the adsorption mechanism of biopolymer‐based membrane adsorbers and accelerate the development of practical applications as the focus of future research. [ABSTRACT FROM AUTHOR]

A promising route to the synthesis of protein‐mimetic materials that are capable of strong mechanics and complex functions is provided by intermolecular β‐sheet stacking. An understanding of the assembly mechanism on β‐sheet stacking at molecular‐level and the related influencing factors determine the potential to design polymorphs of such biomaterials towards broad applications. Herein, we quantitatively reveal the air/water interface (AWI) parameters regulating the transformation from crowding amorphous aggregates to ordered phase and show that the polymorph diversity of β‐sheet stacking is regulated by the chain relaxation‐crystallization mechanism. An amorphous macroscale amyloid‐like nanofilm is formed at the AWI, in which unfolded protein chains are aligned in a short‐range manner to form randomly packed β‐sheets. The subsequent biopolymer chain relaxation‐crystallization to form nanocrystals is further triggered by removing the limitations of energy and space at the AWI. [ABSTRACT FROM AUTHOR]

Current technologies for recovering precious metals suffer from high energy consumption, poor adsorption selectivity, slow adsorption kinetics, poor recyclability and expensively complex recovery processes. Thus, there is an urgent need to develop an ecofriendly system to recover precious metals from resources (e.g., ores, waste electrical components or wastewater) with high capacity and low cost. Here, we report a protein-based bilayer membrane made from the one-step aqueous self-assembly of phase-transitioned lysozyme that can efficiently sequester gold ions from dilute aqueous solutions (0.1 to 400 ppm). Notably, this membrane, with a special design of top microparticles and bottom nanomembrane layers, has a cost comparable to that of activated carbon, and exhibits an adsorption capacity for gold of 1034.4 mg g−1, which is 3–15 times higher than those of the most-utilized industrial adsorbents, such as activated carbon and ion exchange resins. The high adsorption capacity for gold could be further extended to other primary precious metals, and high selectivity towards precious metals was simultaneously maintained when extracting precious metals at <1 ppm from ores or waste electrical leachate solutions containing a large amount of competing metal ions. Without the extra addition of any reductants, the membrane could be further directly used to reduce the adsorbed gold ions, affording gold with a final purity of 23 K (95.8 wt%) after pyrolysis. [ABSTRACT FROM AUTHOR]

ABSTRACT The walnut shell supported nanoscale zero-valent iron (walnut-nZVI) was prepared from sodium borohydride, iron(II) chloride tetrahydrate, and walnut shell by liquid phase chemical reduction and characterized by FTIR, TEM, and XRD. The composites were tested as adsorbent for the removal of Cu(II) or Ni(II) ions. The equilibrium data were analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich, which revealed that Langmuir isotherm was more suitable for describing Cu(II) and Ni(II) ions adsorption than the other two isotherm models. The results indicated that the maximum adsorption capacity was higher than some other modified biomass waste adsorbents under the proposed conditions, were 458.7, 327.9 mg g−1 for Cu(II) or Ni(II). The adsorption kinetics data indicated that the adsorption fitted well with the pseudo-second-order kinetic model. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43304. [ABSTRACT FROM AUTHOR]

To remove multiple pollutants (such as organic dyes, heavy metal ions, emulsified oil droplets, and toxic chemicals) from water resources, developing membranes with multifunctional separation performances is highly demanded. Herein, self-supported nanocomposite membranes with nanoporous structures were fabricated by integrating positively charged amyloid-like oligomers that were obtained by reducing disulfide bonds of native lysozyme onto the surface of negatively charged nanocelluloses via electrostatic interaction and hydrogen bonding. Lysozyme oligomer not only acted as adhesive to glue cellulose nanofibers prepared by 2,2,6,6-tetramethyl-1- piperidinyloxy oxidation (TEMPO), but also reduced the pore size of the resultant membranes to a precise cut-off size of 3 nm. Benefitting from the multiple functional groups (-OH, –COOH, –SH, –NH 2), the resultant nanocomposite membranes could efficiently remove organic dyes, heavy metal ions, bilirubin, oil droplets, and boron from wastewater. Moreover, these membranes showed excellent recyclability, mechanical performance, and acid/alkali resistance. This work provided a fast, economical, and sustainable strategy for the fabrication of multifunctional membranes for wastewater purification from natural resources and renewable nanomaterials. [Display omitted] • Lysozyme was used as an adhesive for the construction of nanocellulose-based membranes. • The nanocomposite membranes could efficiently remove molecules (>3 nm), oil droplets, heavy metal ions, and toxins. • The nanocomposite membranes showed excellent recyclability, mechanical performance, and acid/alkali resistance. [ABSTRACT FROM AUTHOR]