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Polyethyleneimine-functionalized cellulose beads (PCB-PEI) with hierarchical multi-porous structures were fabricated via a novel strategy combining intermolecular pre-crosslinking with glutaraldehyde chemical crosslinking to improve the specific surface area and mechanical performances of PCB-PEI. The resultant PCB-PEI possessed unique hierarchical architecture consisting of surface interpenetrating porous networks, resulting in large specific surface area of 100.61 m2/g and high porosity of 94.27%. In particular, the robust double cross-linking networks endowed PCB-PEI with outstanding stiffness, toughness, and elasticity. The compressive strength was up to 202 kPa, and retained at 94.5 kPa with 84.1% of shape recovery after 10 loading–unloading cycles at 50% compressive strain. Benefiting from its hierarchical multi-porous structure, abundant functional sites, and excellent mechanical properties, PCB-PEI displayed excellent dye adsorption and reusability. The maximum adsorption capacities for methyl blue (MB) and rose bengal (RB) reached 1550.55 and 467.95 mg/g. After 8 cycles, the adsorption capacities of PCB-PEI for MB and RB still maintained more than 97% and 86%, respectively. Predominant electrostatic attraction and hydrogen bond interactions during adsorption process were proposed to improve the adsorption of dyes. Thus, PCB-PEI is a potential, sustainable adsorbent for highly efficient removal of dyes from wastewater. [ABSTRACT FROM AUTHOR]

In this work, a novel and high-efficiency scavenger based on amino-functionalized cellulose was designed for sodium cholate sorption in vitro. To estimate the adsorption performance of the amino-functionalized cellulose for sodium cholate, various factors including sodium cholate concentration, contact time and electrolyte were investigated. The results suggested that amino-functionalization for cellulose regarding to hyperbranched polyethylenimine not only induce positive charge surface of cellulose but also provide abundant and special binding sites for sodium cholate sorption. The amino-functionalized cellulose displayed an excellent performance to sodium cholate sorption with a maximum adsorption capacity of 569.7 mg/g, higher than cholestyramine, a synthetic lipid-lowering drug in clinic. And the adsorption behavior was well fitted into the Langmuir isotherm model and pseudo-second-order kinetic model, suggesting a homogeneous monolayer chemisorption. Furthermore, the amino-functionalized cellulose presented the features of excellent anti-interferences, cytocompatibility and facile preparation process. All these results support amino-functionalized cellulose as a promising prospect for cholesterol elimination. [ABSTRACT FROM AUTHOR]

In this work, carboxylated cellulose beads with highly porous structure were fabricated using phase separation method, and subsequent carboxylation using citrate. The pore structure and average size of the carboxylated cellulose beads could be altered by adjusting reaction temperature and time during carboxylation, in which the average sizes were in the range of 2.08–2.34 mm. Moreover, the resulting porous cellulose beads with open-pore surface exhibited high specific surface area (~ 156.86 m2/g) and high carboxyl group content (~ 4.93 mmol/g). Considering their high specific surface area, surface carboxylation, and eco-friendly, the carboxylated cellulose beads were utilized for removal of cationic dye, methylene blue (MB). The porous, carboxylated cellulose beads exhibited remarkable adsorption performance with a maximum adsorption capacity of 288.81 mg/g, about 8 times higher than unmodified cellulose beads. Also, this porous bead showed a promising application as high-efficient absorbent and its adsorption capacity for MB still retained 250.78 mg/g after ten adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • LDO/vinasse biochar composite was synthesized for phosphate recovery and reuse. • LDO@BC 0.1 exhibits an ultra-high specific surface area of 508.97 m2/g. • LDO@BC 0.1 displays excellent removal capacity for trace phosphate. • P-adsorbed LDO@BC can be used as fertilizer to accelerate plant growth. In this work, CaMgAl-layered double oxide/biochar (LDO@BC) composites were elaborated by hydrothermal coprecipitation and calcination for the efficient recovery of phosphate as well as the further application of the reclaimed composites as fertilizers. On the one hand, the appropriate selection of biochar derived from vinasses as the substrates could solve the limitations of LDO like low specific surface areas as well as poor dispersion. The obtained composites possess the ultrahigh specific surface area as high as 508.97 m2/g. Therefore, a maximum adsorption capacity of 153.64 mg/g is achieved. In addition, our composites are with fast adsorption rates that nearly 100 % phosphate could be removed within 60 s at a trace concentration owing to the large specific surface areas. On the other hand, the recovered adsorbents could be used as fertilizers because of the high contents of P, Ca and Mg elements. The phosphate-adsorbed LDO@BC (P-LDO@BC) demonstrated a positive fertilization effect, significantly accelerating plant growth with length increment by 0.75 times and mass increment by 2.09 times compared with the control groups. Thus, this work not only provides a new approach for waste vinasse utilization, but also presents a promising adsorbing material for phosphate recovery and reuse. [ABSTRACT FROM AUTHOR]

Electric-field driven uranium extraction from seawater has been proved to greatly enhance the performances of various adsorbents via gathering uranyl ions at the surfaces, but high-concentration interfering cations would also be enriched which generates shielding effects to reduce adsorption capacity. To address this issue, we have fabricated nanofiltration membranes with sieving-adsorption properties by choosing polyamidoxime (PAO) as substrates and polyamide as skin layers. On the one hand, the polyamide skin layers fabricated by interfacial polymerization could effectively separate uranyl ions from other metal ions according to the size-sieving effect since the size of uranyl ions is much larger than most interfering cations. The results demonstrated that the nanofiltration membranes could nearly 100 % reject uranyl ions while the rejections of other metal ions below 30 %. On the other hand, the rejected uranyl ions would be enriched at the surfaces of PAO substrates and followed by adsorption. The increased uranium concentrations are beneficial for both adsorption capacity as well as adsorption rate. Therefore, the adsorption capacity increased by 30 % compared with the pristine PAO adsorbents. This work not only provides a new strategy for the design of high-performance adsorbents, but also could promote the engineering process of uranium extraction from seawater which has an important scientific significance and application value. [Display omitted] • Nanofiltration membrane with sieving and adsorption properties is prepared. • Electric fields are beneficial for the gathering of uranium at membrane surfaces. • The NF membranes could separate uranium from interfering metal ions. • The adsorption capacity of NF membrane increased by 154 % compared with the pristine PAO adsorbent. [ABSTRACT FROM AUTHOR]

In this paper, novel hydrogen-bonded metal-complex frameworks MPM-1-TIFSIX and HOF-21 were selected as adsorbents to adsorb iodine. MPM-1-TIFSIX and HOF-21 were prepared by layering method and mixed stirring method, respectively. The structures of the two HOFs were characterized in detail by XRD, BET, TGA and FT-IR. The adsorption behavior and adsorption capacity of MPM-1-TIFSIX and HOF-21 for iodine were investigated in detail. The experimental data showed that the equilibrium adsorption amounts of MPM-1-TIFSIX and HOF-21 were 205.51 mg/g and 172.86 mg/g, respectively. The adsorption process of MPM-1-TIFSIX was conformed to be pseudo-second-order kinetic, while the adsorption process of HOF-21 was conformed to be pseudo-first-order kinetic. The results indicated that HOFs could be used as iodine capture and storage materials. Two different structures of HOF materials were synthesized and used for the capture of iodine. Both materials have different properties, which are related to their structure. MPM-1-TIFSIX with a larger pore size is capable of adsorbing more iodine molecules. HOF-21 can only absorb a small amount of iodine due to the small pores, which can also be seen from the figure. Image 1 [ABSTRACT FROM AUTHOR]

ZIF-67@Yeast was synthesized with in-situ growth procedure by using hydrothermally carbonized yeast as the substrate material. The prepared ZIF-67@Yeast was characterized in detail by SEM, BET, XRD and TG analysis. In addition, the adsorption properties of Pb2+ by ZIF-67@Yeast were also investigated. The results show that the adsorption capacity of Pb2+ by ZIF-67@Yeast is larger than the sum of the adsorption capacity of Pb2+ by individual yeast and ZIF-67. Yeast could maintain a stable morphology after hydrothermal carbonization at 180 °C. Therefore, many MOFs synthesized by hydrothermal or microwave methods at 180 °C could also be compounded with Yeast as a base material. This provides more possibilities that heavy metal ions are adsorbed by the synthesis of more diverse MOFs composites. ZIF-67@Yeast was synthesized by in situ growth using a hydrothermally carbonized yeast as a substrate material, which can maintain a stable morphology and efficient removal of Pb2+ in water. Image 1 • ZIF-67@Yeast was synthesized by using a hydrothermally carbonized yeast as a substrate material. • The adsorption capacity of Pb2+ by ZIF-67@Yeast is larger than that of Pb2+ by individual yeast and ZIF-67. • Many MOFs could also be compounded with yeast as a base material. [ABSTRACT FROM AUTHOR]

This work presents a facile and practical preparation method of cellulose-based bioadsorbent modified by hyperbranched polyethyleneimine (hPEI) using glutaraldehyde cross-linking in heterogeneous system for various dyes removal. The grafting of hPEI with a large molecular structure was achieved efficiently according to the FTIR and XPS analysis. The adsorption properties of the cellulose-based bioadsorbent for anionic reactive yellow X-RG (XRG), cationic bright yellow M-7G (M7G), nonionic disperse brown S-3RL (DB 3) were explored. The kinetics curve was well fitted with pseudo-second-order model, and the equilibrium data well suited Langmuir model with maximum adsorption capacity of 571.43 mg g −1 for M7G, 581.40 mg g −1 for DB 3 and 970.87 mg g −1 for XRG. Compared with other bioadsorbents reported previously, the cellulose-based bioadsorbent could be facilely prepared and simultaneously exhibited enhanced removal for dyes. Therefore, this work will help accelerate the study of scale production of bioadsorbent for treatment of textile effluents. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrophobic interactions and hydrogen bonded self-assembly achieve mild functionalization. • The membrane is with anti-fouling, anti-bacteria, and anti-adhesion properties. • The membranes could maintain 85% of adsorption capacity with various interferences. • The membranes could obtain 1.15 mg/g of uranium when the concentration is 3.3 ppb. Herein, we have developed a mild and convenient strategy to enable polypropylene (PP) fibrous membranes with abundant adsorption sites for the selective extraction of uranium from seawater. Lysozyme was chosen as the pre-coatings because of its strong hydrophobic interactions with PP membranes. Then, lysozyme and phytic acid were set as hydrogen bonding self-assembling components since both of them are proved with a great binding affinity towards uranium. The contents and thickness of the lysozyme-phytic acid coatings could be linearly tuned due to the excellent controllability of self-assembly. The obtained PP membrane could achieve adsorption capacity as high as 90.07 mg-U/g-membrane (2143.83 mg-U/g-coating). In addition, the lysozyme would endow the PP membranes with outstanding anti-fouling, anti-bacteria, and anti-adhesion properties. The modified membranes could maintain more than 85% of adsorption capacity even with the interferences of bacteria and model pollutants. We also applied the membranes for dynamic adsorption by taking advantage of membrane filtrations. The adsorption capacity during the dynamic process increases with the flow rates and the layer numbers because more uranyl ions could contact with the adsorption sites. The modified PP membranes could obtain 1.15 mg/g of uranium after 15 days when the concentration of uranium is set as the same as the uranium concentration (3.3 μg/L) in natural seawater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amyloid-like coatings provide electrodes with binding sites to uranium and anti-fouling properties. • The modified electrodes achieved equilibrium adsorption capacity as high as 2850 mg/g. • Unfolded BSA coatings enable the electrodes with superior reusability and long-term stability. • Both adsorption capacity and adsorption rates are better than most of other adsorbents. Electro-adsorption has been regarded as one of the most effective methods for uranium extraction from seawater since this method could gather ultralow-concentration uranyl ions at the adsorbent surfaces for higher adsorption capacity and adsorption rates. However, the marine microorganisms and pollutants would also migrate to the adsorbent surfaces, causing serious inhibiting effects. Herein, the pristine electrodes were modified by the convenient amyloid-like assembly to solve the above problem. The unfolded bovine serum albumin (BSA) coatings not only offer adsorption sites toward uranium but also enable the electrodes with excellent anti-fouling and anti-adhesion properties. The modified electrodes achieved superior reusability and long-term stability even with the interferences of various pollutants and microorganisms. To the best of our knowledge, the overlooked but pernicious influences of the fouling phenomenon are firstly investigated in electro-adsorption. This finding not only removes the barriers in the practical applications of electro-adsorption, but also guides the design strategy of adsorbents for uranium extraction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cellulose-based absorbents with the highest reported uranium uptake are achieved. • Homogeneous reactions are beneficial to grafting density and material utilization. • Excellent hydrophilicity contributes to rapid mass transfer and antifouling property. • The adsorbents could be filled into filtration columns for dynamic adsorption. • The adsorbents collect 50 mg uranium/g from simulated seawater in 24 d adsorption. Highly efficient extraction of uranium from seawater is regarded as an important guarantee for the promotion of nuclear electricity generation. Amidoxime based adsorbents are considered as the most promising materials for uranium recovery due to their high selectivity and binding capability to uranyl ions. Herein, natural celluloses with advantages of low cost, biodegradability, renewability were chosen as the raw materials. Moreover, amidoximated cellulose-based adsorbents are fabricated by two steps of homogeneous reactions including the Michael addition and amidoximation reaction. Compared with traditional surface grafting methods, both the grafting density of active adsorption sites and the utilization of raw materials could be greatly improved because of the lower steric hindrance as well as more exposed reactive sites during the homogeneous reactions. The adsorption capacity of our adsorbents can reach as high as 517.07 mg/g at pH = 7, one of the best cellulose-based adsorbents as far as we know. In addition, excellent hydrophilicity of the adsorbents, which is inherited from the natural cellulose, can endow them with enhanced mass transfer as well as resistance to marine pollutants. More importantly, the adsorption microspheres would be filled into filtration column for dynamic adsorption benefited from their aforementioned merits. The average adsorption capacity could maintain above 2.5 mg/g per day when the filtration column was exposed to simulated seawater for 24 days. All these characteristics make the amidoximated cellulose-based adsorbents potentially applicable to the uranium recovery from seawater. [ABSTRACT FROM AUTHOR]

It is of great significance to capture radioiodine from nuclear-related activities. Herein, We fabricated two kinds of hybrid aerogels composed with bimetal Hofmann-type metal-organic frameworks (Co–Fe)II(pz)[NiII(CN) 4 ] and cellulose aerogels by in-situ growth and doping method (named CoFe@CA-IS and CoFe@CA-D, respectively). The hybrid aerogels possessed excellent iodine adsorption performance. The addition of (Co–Fe)II(pz)[NiII(CN) 4 ] increased the porosity of the hybrid aerogels. The porosities of CoFe@CA-IS and CoFe@CA-D were reached 86.7% and 87.8%, respectively, which are higher than pure cellulose aerogels. Furthermore, the doping method provide a significant improve of adsorption performance. The equilibrium adsorption capacity of CoFe@CA-D reached 457.99 mg g−1 and the equilibrium adsorption capacity of CoFe@CA-IS was 194.34 mg g−1. In addition, the hybrid aerogels showed excellent recycle ability, the equilibrium adsorption capacity of CoFe@CA-IS and CoFe@CA-D remained 81% and 91% after 5 cycles. The results suggested that this metal-organic framework@cellulose hybrid aerogel showed great potential in iodine treatment and could be applied in a wide field. A metal-organic framework@cellulose aerogel was synthesized and exhibited outstanding adsorption performance for iodine. Image 1 • Bimetal Hofmann-type MOFs are developed and (Co–Fe)II(pz)[NiII(CN) 4 ] shows the excellent iodine adsorption performance. • Two type of hybrid aerogels are successfully fabricated by in-situ growth and doping method. • CoFe@CA-D shows excellent iodine adsorption performance and the equilibrium adsorption capacity remained 91% after 5 cycles. [ABSTRACT FROM AUTHOR]

Robust, metal-free, macroscopic 3D porous CN/CE hybrid photocatalyst was fabricated by the co-assembly of g-C 3 N 4 and cellulose substrate, in which such an interconnected porous network facilitates mass transport, strong adsorption and multireflection of incident light. Consequently, the CN/CE hybrid photocatalyst exhibited both an excellent adsorption capacity and improved photocatalytic activity toward methylene blue degradation with degradation rate of 99.8%. • Robust, metal-free, 3D porous g-C 3 N 4 /cellulose hybrid photocatalyst was fabricated. • Highly porous network facilitates mass transport, adsorption and light multireflection. • Syncretic interface between g-C 3 N 4 and cellulose increases photoelectrons transfer. • Methylene blue removal ratio over the CN/CE hybrid photocatalyst reaches up to 99.8%. • The CN/CE hybrid photocatalyst exhibits mechanical stability and high reusability. Robust, metal-free, macroscopic 3D porous g-C 3 N 4 /cellulose (CN/CE) hybrid photocatalyst was successfully fabricated by the co-assembly of g-C 3 N 4 and cellulose substrate. The morphology, structure, mechanical property, optical and electrochemical performances, and photocatalytic activity of the CN/CE were investigated in detail. The obtained CN/CE hybrid photocatalyst possessed homogeneous 3D interconnected network structure, excellent mechanical strength and considerable recyclability. Also, the CN/CE hybrid photocatalyst exhibited both an excellent adsorption capacity and improved photocatalytic activity toward methylene blue (MB) degradation with degradation rate of 99.8%, much higher than that of pure g-C 3 N 4 (54.2%). The enhanced photocatalytic performance of CN/CE derived from the synergistic effects of homogeneous 3D interconnected network structure and syncretic interfaces between g-C 3 N 4 and cellulose, facilitating mass transport, light absorption and reactant adsorption, as well as the transfer of the photogenerated electrons. Moreover, the CN/CE hybrid photocatalyst indicated a high reusability and stability without significant reduction in its efficiency with nearly 96% of MB degradation after four cycles. This work not only demonstrated the importance of homogeneous interconnected network structure to prepare highly effective photocatalyst, but also provided a new insight into the approach for design and utilization of stable and recyclable metal-free photocatalyst for visible light derived contaminant degradation. [ABSTRACT FROM AUTHOR]