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[Display omitted] Phosphate-induced water eutrophication has attracted global attention. Fabricating adsorbents with both high phosphate adsorption affinity and accessible separation property is challenging. Herein, PG@NZL, a hierarchical nanocomposite fibrous membrane, was fabricated via in-situ growth of La-doped NiZn-LDH (NiZnLa 0.1) over electrospun graphene oxide-polymer composite fibers (PG). The porous surface of the PG fibers provided abundant anchor sites for the vertical self-supported growth of NiZnLa 0.1 nanosheets, contributing to a high surface area. The La-doped NiZnLa 0.1 trimetallic LDH achieved a much higher adsorption capacity than NiZn-LDH. The negative adsorption energy (-1.45 eV), calculated with DFT, confirmed its spontaneous adsorption potential for phosphate. Interestingly, the PG fibers contributed to oxygen vacancies and the metal center electronic structure evolution of NiZnLa 0.1 , thus strengthening the coordination with phosphate. Mechanistic analysis revealed that the high adsorption capacity of PG@NZL is attributed to its superior anion exchange property, oxygen vacancies, and inner-sphere complexation. Therefore, the flexible and easily separated PG@NZL nanocomposite fibrous membrane is a promising adsorbent for effectively treating phosphate-bearing wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] Phosphate-induced water eutrophication has attracted global attention. Fabricating adsorbents with both high phosphate adsorption affinity and accessible separation property is challenging. Herein, PG@NZL, a hierarchical nanocomposite fibrous membrane, was fabricated via in-situ growth of La-doped NiZn-LDH (NiZnLa 0.1) over electrospun graphene oxide-polymer composite fibers (PG). The porous surface of the PG fibers provided abundant anchor sites for the vertical self-supported growth of NiZnLa 0.1 nanosheets, contributing to a high surface area. The La-doped NiZnLa 0.1 trimetallic LDH achieved a much higher adsorption capacity than NiZn-LDH. The negative adsorption energy (-1.45 eV), calculated with DFT, confirmed its spontaneous adsorption potential for phosphate. Interestingly, the PG fibers contributed to oxygen vacancies and the metal center electronic structure evolution of NiZnLa 0.1 , thus strengthening the coordination with phosphate. Mechanistic analysis revealed that the high adsorption capacity of PG@NZL is attributed to its superior anion exchange property, oxygen vacancies, and inner-sphere complexation. Therefore, the flexible and easily separated PG@NZL nanocomposite fibrous membrane is a promising adsorbent for effectively treating phosphate-bearing wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] Hazardous oxyanions in water bodies are potentially toxic to aquatic life, and the coexistence of multiple anions aggravates the toxicity. Herein, bowknot-like Zr/La bimetallic organic frameworks (Zr/La-BTC) were developed with superior hazardous oxyanion adsorption capacities, i.e., approximately 102 mg/g for arsenate and 159 mg/g for phosphate, respectively. The molar ratio of Zr to La in Zr/La-BTC plays a significant role in the structure and the adsorption efficiencies. Notably, the experiment-derived adsorption capacities of various Zr/La-BTC samples were consistent with their adsorption energies calculated by density-function theory (DFT). Further mechanism analysis revealed that coordination of Zr/La atoms with the target anion groups occurred during adsorption. The positive shift of binding energies in La 3d and Zr 3d XPS spectra and Bader charge analysis unveiled that back-donation interactions dominated the adsorption process. The reliable adsorption selectivity and reusability of 0.1Zr/La-BTC were verified with anion competition experiments and four adsorption-desorption cycles. Overall, this study provides significant insight into the design of high-performance bimetallic organic frameworks for the enhanced removal of hazardous oxyanions from water. [ABSTRACT FROM AUTHOR]

• A 3D rice-like hierarchical nanocomposite was designed by anchoring La species into LDH matrix. • La@MgAl achieved high adsorption capacities for both phosphate and fluoride. • Satisfactory selectivity and reusability of the adsorbent were proved. • Interlayer sorption and inner-sphere complexation were main mechanisms for excellent adsorption performance. • La@MgAl was effective for synchronous phosphate and fluoride remediation in real wastewater. The frequent occurrence of algae boom and skeletal fluorosis has drawn global attention to developing feasible technologies for phosphate and fluoride removal from water bodies. This study reported the synthesis of novel three-dimensional rice-like La@MgAl nanocomposites by anchoring La species into Mg-Al LDH matrix to achieve effective and synchronous phosphate and fluoride capture. Results from multiple detection methods including XRD, SEM, FTIR, and XPS revealed the introduced La cations could serve as a structural inducer to regulate the crystallinity of the La@MgAl composites and rice-like nanocomposite La@MgAl-1 was fabricated under optimal La loading amount. La@MgAl-1 possessed high adsorption capacities for both phosphate and fluoride (101.59 mg/g and 51.03 mg/g, respectively). The effective adsorption performance also sustained even after five adsorption-desorption cycles, indicating favorable reusability. The adsorption mechanism analysis revealed that the presence of unique hydrotalcite-like structure triggered memory effect to exert strong adsorption of P and F anions into the interlayered gallery. Besides, an optimum amount of La species organized on the composite wielded specific anion adsorption to phosphate and fluoride through inner-sphere complexation and ligand exchange. These encouraging results highlight the positive consequence of combining the strategic La species and LDH matrix to render a nanostructured Mg/Al/La ternary metal assembly in which various components are united in a controllable way to exert collective properties for accumulative anion adsorption properties. Besides, this study offered promising candidates for real water purification against phosphate and fluoride pollution. [ABSTRACT FROM AUTHOR]

• A cost-effective periclase-based pathway was proposed for adsorbent synthesis. • Novel Mg-La bimetal oxide nanocomposite was prepared. • Optimal urea amount induced 3D needle-like nanostructure. • Superior P and F adsorption capacities were achieved. • Inner-sphere complexation dominated the adsorption mechanism. Phosphate and fluoride are primary culprits of water eutrophication and skeleton fluorosis, respectively, severely threatening the security of aquatic lives and public health. To deal with the aqueous phosphate and fluoride pollution, PC@La nanocomposites were tailor-designed based on low-cost periclase and lanthanum salt via a facile urea hydrothermal method. Results from SEM, XRD, FTIR, XPS analysis revealed the PC@La-1.0 was constructed by Mg-La bimetal carbonated hydroxides with the three-dimensional needle-like nanostructure. Highly effective adsorption capacities for both phosphate (107.34 mg/g) and fluoride (63.11 mg/g) were achieved by PC@La-1.0. The adsorption was pH-dependent, and the optimal pH values for adsorption was 4.0–6.0. Over 80% of initial adsorption capacities remained after four adsorption–desorption cycles, indicating its satisfactory reusability. Superior adsorption selectivity for phosphate and fluoride was proven when co-existing with common ions and organics in solutions and real sewage. Mechanism analysis revealed that the unique structure of Mg-La bimetal carbonate hydroxide structure of PC@La-1.0 promoted an accumulative anion adsorption performance. Mg and La cations on PC@La-1.0 formed strong inner-sphere complexation with target phosphate and fluoride while the internal carbonate and hydroxyl groups contributed to adsorption via ion exchange. This study highlights the novel low-cost method to prepare promising candidates for efficient dephosphorization and defluorination from water. [ABSTRACT FROM AUTHOR]

The over-reliance on tetracycline antibiotics (TC) in the animal husbandry and medical field has seriously affected the safety of the ecological environment. Therefore, how to effectively treat tetracycline wastewater has always been a long-term global challenge. Here, we developed a novel polyethyleneimine (PEI)/Zn-La layered double hydroxides (LDH)/cellulose acetate (CA) beads with cellular interconnected channels to strengthen the TC removal. The results of the exploration on its adsorption properties illustrated that the adsorption process exhibited a favorable correlation with the Langmuir model and the pseudo-second-order kinetic model, namely monolayer chemisorption. Among the many candidates, the maximum adsorption capacity of TC by 10 %PEI-0.8LDH/CA beads was 316.76 mg/g. Apart from that, the effects of pH, interfering species, actual water matrix and recycling on the adsorption of TC by PEI-LDH/CA beads were also analyzed to verify their superior removal capability. The potential for industrial-scale applications was expanded through fixed-bed column experiments. The proven adsorption mechanisms mainly included electrostatic interaction, complexation, hydrogen bonding, n-π EDA effect and cation-π interaction. The self-floating high-performance PEI-LDH/CA beads exploited in this work provided fundamental support for the practical application of antibiotic-based wastewater treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Elastic brushite/polyethyleneimine/nanofibrillated cellulose aerogel was developed. • The coupling of brushite and polyethyleneimine enhanced adsorption property. • PNFCA/BRU-0.2 exhibited high selectivity for Cu(II) with 332.66 mg/g. • The continuous flow purification of copper-containing wastewater was realized. • PNFCA/BRU-0.2 could block the toxicity of heavy metals to crops. To achieve efficient removal of copper(II) from heavy metal wastewater, designing an eco-friendly and low-cost adsorbent is highly desirable. Here, a novel air- and underwater shape-memory cellulose aerogel was reported via coupling brushite and polyethyleneimine (PEI)-modified nanofibrillated cellulose (NFC) for selectively adsorbing Cu(II) ions. The adsorption kinetic and isotherm studies were consistent with pseudo-second-order model and Langmuir model, indicating the removal of Cu(II) was a monolayer chemisorption process. Benefiting from the open three-dimensional (3D) framework structure and abundant exposed active sites, such compressible aerogel exhibited excellent adsorption capacity of 332.66 mg/g for Cu(II). In addition, the developed aerogel could be conveniently used as a continuous flow filter for successive purification of industrial wastewater, where the up-to-standard treatment volume was about 5.6 L. The Cu(II)-loaded aerogel could be regenerated after being eluted by 0.1 M EDTA-2Na, and its structure, shapeability and selective adsorption properties were hardly affected even after 8 consecutive cycles. Mechanistic analysis confirmed that the surface complexation, ion exchange and chemical deposition were the main driving forces for the superior adsorption performance. Finally, PNFCA/BRU could inhibit the contamination of crops by heavy metals, which was a great safeguard for wheat growth. [ABSTRACT FROM AUTHOR]

[Display omitted] • SA/PEI-0.25 aerogel showed high elastic, stability and adsorption performance. • The maximum adsorption capacities of Cr(VI) and Cd(II) were 678.67 and 464.23 mg/g. • The fixed-bed continuous filtration of Cr(VI) and Cd(II) wastewater was realized. • SA/PEI-0.25 aerogel reduced the toxicity of heavy metal ions to rice. • The adsorption mechanisms of Cr(VI) and Cd(II) were investigated. Herein, an elastic polyethyleneimine/sodium alginate aerogel was designed by a one-step freeze-drying method. The 3D honeycomb-like structure endowed it excellent compressibility and plentiful exposed adsorption sites to accelerate Cr(VI) and Cd(II) adsorption. The adsorption processes matched the pseudo-second-order and Langmuir models, and the saturated adsorption capacity for Cr(VI) and Cd(II) was 678.67 and 464.23 mg/g, respectively. The obtained aerogel still expressed superior removal performance for Cr(VI) and Cd(II) even in the coexistent of multiple interfering factors and maintained stable adsorption capacity at least after 5 cycles. Importantly, the elastic cylindrical aerogel (∼0.59 g) could achieve dynamic filtration of industrial wastewater containing Cr(VI) and Cd(II) in fix-bed column system with corresponding effective treatment volume of 4.47 and 3.25 L, respectively. The reasonable mechanisms for the adsorption behaviors of heavy metals on the as-prepared aerogel was investigated via FTIR, XPS and Density functional theory (DFT), which could be attributed to the surface electrostatic adsorption, chelation and reduction effects. Eventually, the ecological assessment verified that eco-friendly SA/PEI aerogel had a powerful auxiliary effect on the anti-fouling growth of rice. Overall, such novel biomass aerogel adsorbent possessed great application potential and theoretical guiding significance for the purification of heavy metal wastewater. [ABSTRACT FROM AUTHOR]

The extensive use of tetracycline (TC) as veterinary therapeutics and animal growth promoters has caused human health problems. Some adsorbents have been developed to remove TC, but the adsorption capacity is still unsatisfactory. Here, we synthesized octahedral cuprous oxide nanocrystals (oct-Cu 2 O NCs) by a hydrothermal method at room temperature. Surprisingly, the maximum adsorption capacity of oct-Cu 2 O NCs reached an astonishing amount of 1112.6 mg/g. Adsorption kinetics and isotherm experiments for TC removal were carried out to evaluate its potential as an adsorbent. The key factors like pH and solution ions as well as the mechanism of TC adsorption on oct-Cu 2 O NCs were also studied. The main adsorption process may be that the hydroxyl group (-OH) on the {111} facets surface of oct-Cu 2 O NCs is replaced by the amino group (-NH 2) of TC. The high adsorption capacity is generated by the abundant Cu atoms with dangling bonds on the {111} facets surface and the strong chemical coordination between the -NH 2 of TC and Cu(I). This work provides an alternative with a promising application prospect for the treatment of TC in water. Unlabelled Image • Oct-Cu 2 O NCs with {111} facets were prepared through a simple hydrothermal method. • Oct-Cu 2 O NCs possess excellent tetracycline adsorption performance. • A large number of adsorption active sites are on the {111} facets. • Strong adsorption is generated by the coordination between -NH 2 of TC and Cu(I). [ABSTRACT FROM AUTHOR]