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This work introducing a pioneering catalytic routes and processes facilitating the effective and efficient extraction of U(VI) from nuclear wastewater based on CEC. [Display omitted] • An innovative approach of contact-electro-catalysis (CEC) was proposed for U(VI) extraction. • U(VI) in a wide concentration range of uranium solutions can be completely removed by CEC. • The efficient and selective extraction of U(VI) was realized in actual nuclear wastewater. • The mechanism of U(VI) removal by CEC was revealed. The efficient and eco-friendly extraction of uranium(VI) from nuclear wastewater continues to pose a significant challenge. Herein, an innovative approach of contact-electro-catalysis (CEC) has been employed for the extraction of uranium from aqueous solutions. Commercial polytetrafluoroethylene (PTFE) was utilized as a trigger catalyst to generate e-, · O 2 − and H 2 O 2 under ultrasonic stimulation. These then react with uranyl ions to yield (UO 2)O 2 ⋅2H 2 O precipitates, facilitating efficient and selective extraction of uranium. In the absence of sacrificial agents, without the requirement of material preparation, and ambient atmosphere conditions, the removal rate of U(VI) at concentrations ranging from 1 to 100 mg/L under ultrasonic action (40 kHz, 180 W) exceeded 95 %. Additionally, it showed significant selectivity in the presence of coexisting ions. Furthermore, PTFE exhibits remarkable reusability in the process of uranium removal by CEC owing to its outstanding physicochemical stability. Notably, 82.6 % of U(VI) in actual low-concentration uranium-containing wastewater was extracted through CEC, confirming this method holds a promising application prospect. Our findings offer a convenient and eco-friendly strategy for effective and efficient extraction of uranium from nuclear wastewater based on the CEC, demonstrating powerful potential for practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrasound-enhanced Ba(OH) 2 removes arsenic and recycles alkaline from high alkaline solution. • The arsenic precipitation rate was 93.30%, which is 77.51% higher than conventional. • Ultrasound reduces the apparent activation energy and promotes solid–liquid interfacial reaction. • The recycled alkaline solution achieved again a high arsenic leaching rate from the slag. Alkaline leaching has become one of the most commonly used methods to treat arsenic-containing waste. Efficient removal of arsenic from the high alkaline solution and reuse of alkali have become a crucial issue in its industrial application. In this study, ultrasound is used to strengthen the arsenic removal from high-alkali solutions by forming precipitation of barium arsenate and recover alkali. Under the optimal conditions, the arsenic in the alkaline solution is reduced from 3.78 to 0.25 g/L. The arsenic precipitation percentage under ultrasound is 93.30 %, which is 77.51 % higher compared to conventional arsenic precipitation. The kinetic experiments indicated that the introduction of ultrasound reduced the apparent activation energy by 23.62 kJ/mol. In addition, the precipitated phases were analyzed to investigate the removal mechanism of ultrasound-enhanced arsenic precipitation. Ultrasound can strip off the sediment wrap and promote solid–liquid interfacial reactions. After arsenic removal, alkaline solution was used to leach arsenic from zinc slag, and the arsenic leaching percentage reached 90.39 %, achieving the recycling of high alkaline solution. This work proved that ultrasonic strengthening technology is an effective green technology for removing arsenic and recovering alkali from high alkaline arsenic-containing solution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe@N-BC was fabricated using a positively charged biochar as the host. • Fe@N-BC can preferably and rapidly sequester phosphate from waters. • N-BC promoted the dispersion of ferric oxide and pre-enrichment of phosphate. • Fe@N-BC can effectively treat the synthetic phosphate-polluted in column settings. To overcome application limitation of the available biochar-based metallic oxide composites for the removal of anionic pollutants like phosphate, a new strategy was proposed that metallic oxide was anchored in the positively charged biochar, acquired by introducing high-density quaternary ammonium groups. The resultant nanocomposite adsorbent Fe@N-BC exhibited high adsorption speed, capacity and preference to phosphate. In the existence of competing anion Cl- at higher levels, Fe@N-BC possessed 3–5 times greater working adsorption capacity of phosphate than a commercial phosphate adsorbent D201 and the mixture of ferric oxide and N-BC with the same proportion as the composite. Fixed-bed adsorption runs of Fe@N-BC could treat ∼ 194 bed volumes (BV) of a synthetic phosphate-polluted wastewater before breakthrough achieving (<0.1 mg P/L in effluent), about 7.46 times greater than that of D-201. The saturated Fe@N-BC could be thoroughly regenerated with 10 % NaOH solution for repeated use with negligible loss of adsorption capacity and ferric. The specific inner-sphere complexation between phosphate and the immobilized ferric oxide was proven to the dominant pathway for preferable adsorption of phosphate onto Fe@N-BC. The obviously enhanced removal of phosphate by Fe@N-BC was ascribed to the introduced quaternary ammonium groups in N-BC, which triggered the dispersion of the impregnated ferric oxide nanoparticles (with sizes of 8.8 ± 1.0 nm) and Donnan member effect. Besides, Fe@N-BC was preliminarily proven to have no biotoxicity. This study can shed new light on how to expand the application of the traditional biochar-based composites to the decontamination of anionic pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of Potassium-Zinc Hexacyanoferrate and their SPEEK Composite Cation Exchange Membranes. • Composite membranes exhibited a high removal/recovery for Cs+ ions than Na+, K+, Mg2+ and Ca2+. • The composite membrane exhibited a remarkable removal efficiency for Cs+ ion, which is 33.85 times higher than that of SPEEK membrane. • Promising candidate for the selective removal/recovery of cesium ions from aqueous solution in presence of interfering ions. Potassium-Zinc hexacyanoferrate adsorbent was prepared by precipitation method and further its composite membrane has been fabricated using sulphonated poly (ether ether ketone) (SPEEK) to investigate cesium (Cs+) recovery from aqueous media. The formation of desired adsorbent material was confirmed by Powder X-ray diffraction (PXRD) while chemical structure was assessed by Fourier-transform infrared spectroscopy (FT-IR). The BET surface area, pore volume and pore diameter found as 298.6 m2/g, 0.1034 cm3/g and 3.04 nm respectively calculated by Brunauer and Emmett and Teller (BET) surface area analyzer. The adsorbent synthesized was observed to work efficiently with maximum adsorption capacity of 54.64 mg Cs/g of adsorbent for Langmuir isotherm model. There was no effect of competing ion (Na+, K+, Mg2+, Ca2+) on adsorption performance during Cs+ removal. Cs+ recovery from the aqueous system in presence of 1000 ppm NaCl was performed using SPEEK composite membrane by electrodialysis. Observing the electrodialysis performance, composite membrane exhibited a high removal/recovery for Cs+ ions than Na+, K+, Mg2+ and Ca2+. The composite membrane exhibited a remarkable removal efficiency for Cs+ ion, which is 33.85 times larger than pristine SPEEK membrane. These results confirm composite membrane as promising candidate for the selective recovery/removal of cesium ions from aqueous solution in existence of intrusive ions and can effectively be applicable for industrial applications. [ABSTRACT FROM AUTHOR]

• Hydroxyl-enriched MONs was facile synthesized for enhanced removal of TBBPA. • The MON-2OH gave a maximum adsorption capacity of 326.8 mg g−1 for TBBPA. • The hydrogen bonding and π-π interaction dominate the good adsorption. Here we report the rational design and facile synthesis of hydroxyl-enriched microporous organic networks (MON-OH and MON-2OH) for enhanced and efficient adsorption and removal of a typical brominated flame retardant tetrabromobisphenol A (TBBPA) from aqueous solution. Introducing of hydroxyl groups into MONs' networks lead to the significant improvement of their hydrophilicity and adsorption capacity for TBBPA. Rely on the good hydrophobicity and predesigned hydrogen bonding sites, the synthesized MON-2OH gave a large adsorption capacity of 326.8 mg g−1 for TBBPA, which is much higher than MONs and many other reported sorbents. The adsorption of TBBPA on MON-2OH followed Langmuir and pseudo-second-order kinetic adsorption models. The TBBPA adsorption capacity was independent on ionic strength (0–30 mg g−1), humic acid (0–40 mg g−1) and pH (5.0–8.0). MON-2OH also gave good stability and reusability and owned good practicability for the removal of TBBPA from wastewater samples. Efficient adsorption and removal of other biphenol pollutants was also achieved on MON-2OH. The adsorption mechanisms of TBBPA on MON-2OH were also well elucidated. This work provides a promising way to design and synthesize efficient adsorbents for TBBPA, which may also promote the design, synthesis and application of functionalized MONs in environmental and material science. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Bifunctional nanocomposite with magnetic and fluorescence property was synthesized. • The nanocomposite consists of fluorescent carbon dots and magnetic MnFe 2 O 4. • The fluorescence indicates the efficient adsorption of U(VI) on the nanocomposite. • The adsorption capacity increases by two times than the single magnetic MnFe 2 O 4. Abstract Magnetic nanomaterials are promising adsorbents for their superior performance in the elimination of radioactive ions from aqueous solution. In this study, a new kind of fluorescent carbon dots were successfully introduced into MnFe 2 O 4 to fabricate magnetic polyethyleneimine-functionalized carbon quantum dots/MnFe 2 O 4 (PECQDs/MnFe 2 O 4) nanocomposites by a simple hydrothermal method, which combined the fluorescent characteristic of CQDs, adsorption capacity of polyethyleneimine and magnetic separation property of MnFe 2 O 4. Detailed characterization certified the formation of nanohybrid composites and its integrating advantages of fluorescence property and magnetism separation, which demonstrated its potential in immobilizing U(VI) and monitoring the adsorption process simultaneously in wastewater. The obtained PECQDs/MnFe 2 O 4 was applied to remove U(VI) from aqueous solution and showed superior construction stability and adsorption capacity of 194 mg/g. Moreover, the kinetic and thermodynamic results suggested that the immobilization of U(VI) was an endothermic and spontaneous multilayer adsorption dominated process. In the end, the cation exchange and interaction between uranyl ions and abundant functional groups (i.e., NH 2 , OH and COOH) on PECQDs/MnFe 2 O 4 were revealed to be responsible for the enhanced adsorption of U(VI), which was realized by forming outer-sphere surface complexes in the removal process. This study proposed an ultrafast-kinetics and high-efficiency adsorbent for U(VI) sequestration, which has a great application potential due to its outstanding recycling performance. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A facile room-temperature stirring method was explored to synthesize MONs. • The MONs gave an adsorption capacity of 227.3 mg g−1 for TBBPA. • The π-π and hydrophobic interaction dominate the good adsorption of TBBPA on MONs. Abstract Development of energy-saving and rapid strategies to synthesize novel porous materials for efficient adsorption and removal of environmental pollutants is of great challenge and interest either in environmental science or in chemistry. Here we report a facile room temperature stirring method for rapid synthesis of microporous organic networks (MONs) with large surface area, excellent hydrophobicity, good thermal and solvent stabilities for efficient adsorption and removal of a typical brominated flame retardant tetrabromobisphenol A (TBBPA) from aqueous solution. The adsorption kinetics, isotherms and thermodynamics, effects of pH, ionic strength, humic acid, regeneration and reusability of MONs for TBBPA were studied in detail. The adsorption of TBBPA on MONs followed the pseudo-second-order kinetic and Langmuir adsorption models. Rely on the good π-π and hydrophobic interaction between MONs and TBBPA, a maximum adsorption capacity of 227.3 mg g−1 was realized, which is the largest adsorption capacity for TBBPA among all the reported sorbents up to date now. The large adsorption capacity, rapid adsorption kinetics, good stability and reusability make MONs a highly potential adsorbent for TBBPA removal from aqueous solution. This work may also promote the synthesis and application of MONs in pollutants' removal. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • nZVI/ATP composite was successfully prepared to activate PMS for removing quinclorac. • Attapulgite increased the dispersion of iron nanoparticles and their reactivity. • The effect factors of nZVI/ATP activating PMS and its reusability were studied. • The intermediate products of quinclorac were identified and most of the intermediate products were mineralized. Abstract A nanocomposite of nZVI/ATP with nanoscale zero-valent iron(nZVI) supported on attapulgite(ATP) was synthesized for activating peroxymonosulfate (PMS) to generate reactive free radicals for quinclorac removal. The microstructures of nZVI/ATP were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Scanning electron microscopy, and N 2 adsorption-desorption. The effect factors of nZVI/ATP-PMS system on quinclorac degradation were tested, including PMS dosage, nZVI/ATP dosage, initial solution pH, initial quinclorac concentration, common existing ions and temperature. Quinclorac degradation products were identified by LC-MS/MS, and the possible degradation mechanism was proposed. The results showed that nanoscale zero-valent iron (nZVI) was evenly dispersed on the attapulgite surface, which effectively prevents the agglomeration and oxidation of nZVI and improves its catalytic performance. The removal efficiency of quinclorac was 97.36%, in an hour using 0.5 g/L nZVI/ATP 3 and 10 mM PMS. The total organic carbon was removed as high as 79.97%. Quinclorac was degraded into five major products by chemical reactions of hydroxyl substitution, oxidation and ring-cleavage. Finally, most of the degradation products were mineralized into inorganics such as CO 2 , H 2 O or something else. It turned out that nZVI/ATP-PMS was a highly efficient catalytic degradation system for removing quinclorac residues in aqueous solution. [ABSTRACT FROM AUTHOR]

Highlights • Chlorination and thermal treatment was applied to remediate HMs contaminated soils. • Treatment was achieved in an industrial plant. • Treatment efficiently removed Pb and Cd, but not Cu, Zn, Cr and Ni. • Treatment transformed available fractions of HMs to a stable residual fraction. • Treated soils satisfied environmental standards for toxic HMs. Abstract Heavy metals contaminated soils are a potential exposure hazard to the public. This study demonstrated the application of chlorination and thermal treatment for remediation of heavy metals-contaminated soils on a full-industrial scale. Five soil samples were treated at a soil remediation factory equipped with an internally-heated rotary kiln (length: 17 m; diameter: 4 m; rotating speed: 0.60 rpm). The target soil temperature was set at about 950 °C. During treatment, calcium chloride was added to facilitate chlorination. The chlorination and thermal treatments effectively removed Pb and Cd and led to the slight removal of Cu and Zn but was not effective for Cr and Ni. Chlorination and thermal treatment also significantly reduced the bioaccessibility of heavy metals in soils, particularly Pb and Cd. The results of sequential extraction revealed that thermal treatment generally decreased the carbonate (C2), Fe/Mn oxide (F3) and organic matter (O4) fractions but tended to increase the residual (R5) fractions of heavy metals, indicating that the chlorination and thermal treatment also favored the immobilization of heavy metals. Overall, the results of this study suggest that remediation of heavy metals-contaminated soils by chlorination and thermal treatment is technologically feasible and that there is great potential for practical application of this method. [ABSTRACT FROM AUTHOR]

Highlights • GO was biogenically reduced to RGO by a green tea extract. • Pb(II) removal efficiency was related to GO reduction conditions. • Highest Pb(II) removal (97.2%) by RGO occurred. • This study provides new insights into the mechanism of GO reduction. Abstract Graphene has a great potential in environmental remediation due to its unique physical and chemical properties. However, the relationships between synthetic conditions and contaminant removal are still unclear. In this study, a biogenic method was used for the reduction of graphene oxide (GO) using green tea extract and the reduced graphene oxide (RGO) produced was subsequently used to remove Pb(II) from aqueous solution. Hence, the impact of bioreduction synthetic conditions of RGO on Pb(II) removal efficiency was examined. The new findings included (1) that reduction of GO by green tea (GT) extract at a ratio of 2:1 (GO:GT), 80 °C and pH 8, led to a RGO material capable of removing 97.2% of a 10 mg·L−1 Pb(II) solution under the adsorption conditions of pH 4.5 and a RGO dose of 0.4 g·L−1 at 30 °C; (2) characterization results showed good dispersion of RGO, and removal of oxygen functional groups from GO, increased Pb(II) adsorption. Pb(II) removal efficiency was largely dependent on reduction conditions during synthesis of RGO; where efficient removal of oxygen-containing groups during reduction favored Pb(II) removal. Furthermore, during biogenic synthesis RGO was also capped by biomolecules such as polyphenols which decreased aggregation leading to enhanced Pb(II) removal efficiency. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A multi-templates MIP was prepared by surface molecularly imprinting technology. • The MIP showed remarkable adsorption capacity, kinetics and reusability. • The MIP exhibited good adsorption selectivity towards alkylphenols. • The MIP was used as the MSPE adsorbent for alkylphenols detection. • Real water samples were analyzed with satisfactory results. Abstract A novel multi-templates molecularly imprinted polymer (MIP) was prepared on the surface of mesoporous silica coated magnetic graphene oxide (MGO@mSiO 2), and applied for the rapid and selective detection of alkylphenol compounds including bisphenol A (BPA), 4-tert-octylphenol (4-tert-OP) and 4-nonylphenol (4-NP) in water. The synthesized composite was characterized by Fourier transform infrared spectrometer, vibrating sample magnetometer, transmission electron microscopy and Brunauer-Emett-Teller surface area analyzer. The MIP showed high adsorption capacity, good selectivity and fast kinetic for these alkylphenols. The maximum adsorption capacities of the MIP for BPA, 4-tert-OP and 4-NP were 16.81, 35.97 and 61.73 mg g−1, respectively, which were significantly higher than those of the non-molecularly imprinted polymer (NIP) due to the imprinting effect. The adsorption of alkylphenols reached equilibrium within 30 min, and followed pseudo-second-order kinetic model and Langmuir model well. The MIP exhibited good sorption selectivity towards BPA, 4-tert-OP and 4-NP, and could be reused 5 times. Furthermore, a new method for ultrasensitive determination of BPA, 4-tert-OP and 4-NP in water by high performance liquid chromatography was developed, using MIP-based magnetic solid-phase extraction coupled with dispersive liquid-liquid microextraction. Under the optimum conditions, the limits of detection (LODs) for BPA, 4-tert-OP and 4-NP were 0.013, 0.010 and 0.010 μg L−1, respectively. The proposed method was used to the detection of BPA, 4-tert-OP and 4-NP in real water samples, with spiked recoveries of 81.5–104.1% and relative standard deviations (RSDs) of 1.0–7.6%, indicating the multi-templates MIP could be a promising adsorbent for separation and analysis of alkylphenols. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tea polyphenols promoted the production of Mo(IV-VI) species in Mo/nZVI@GT. • Mo/nZVI@GT transportability was improved with the increase of Mo incorporation. • Molybdate modification improved the Cr(VI) reduction capacity of Mo/nZVI@GT. • Mo(IV-VI) species favored greater reduction of Cr(VI) to Cr 2 O 3 rather than Cr(OH) 3. The in situ remediation of hexavalent chromium (Cr(VI)) pollution in groundwater and soil using nano zero-valent iron (nZVI) has garnered great attention. However, Cr(VI) remediation, particularly its reduction remains limited in the subsurface due to the poor migration of nZVI materials to contaminated sites. Herein, we successfully prepared a series of Mo/nZVI@GT materials with varying Mo/Fe synthesis molar ratios using green tea extracts and molybdate and efficiently improved the transportability of Mo/nZVI@GT. The pronounced size-selective retention of Mo/nZVI@GT in water-saturated porous media also favors for the effective reaction with Cr(VI) during their cotransport. Moreover, Cr(VI) reduction capacity of Mo/nZVI@GT was remarkably improved at pH 6.0, especially in the presence of phosphate. Mechanistically, X-ray absorption near-edge spectroscopy (XANES) and X-ray photoelectron spectroscopy (XPS) revealed that tea polyphenols promoted the production of Mo(IV) species in Mo/nZVI@GT, which enhanced the conversion of Cr(VI) to Cr 2 O 3 rather than Cr(OH) 3. Additionally, the increased Mo(IV) and Fe(II) active sites might mitigate phosphate disturbance. This study elucidated the mechanisms of Cr(VI) reduction and removal by green synthesized nZVI@GT with Mo modification during their cotransport and highlighted the potential application of Mo/nZVI@GT composites in efficient in situ remediation of Cr(VI)-contaminated groundwater and soil. [ABSTRACT FROM AUTHOR]

• Synergetic interactions between ZVI and Sch during premixing process existed. • Premixing time and mass ratio played essential roles in As(III) removal. • Mass and electron transfer occurred between Sch and ZVI during the premixing. • Recrystallization of Sch and the corrosion process of ZVI were accelerated. • As(III) removal capacity of ZVI/Sch mixtures improved by premixing. Although the enhanced removal of heavy metals using zero valent iron (ZVI) assisted by schwertmannite (Sch) was achieved in previous studies, their interactions between Sch and ZVI seems to be bidirectional and impact on the As(III) removal by ZVI/Sch mixture remains elusive. This study investigated As(III) removal in the mixed suspensions of ZVI and Sch with various premixing times and mass ratios. Batch experiments demonstrated that ZVI/Sch mixture with the premixing time of 3 h and mass ratio of 2:1 exhibited excellent performance in As(III) removal. The results indicated that synergetic interactions between ZVI and Sch during premixing process played crucial roles, particularly in terms of morphological variations. Results of FTIR and XPS revealed the mass and electron transfer occurred between Sch and ZVI during the premixing process, resulting in the accelerated recrystallization of Sch and the corrosion process of ZVI. Furthermore, the premixing process was found to significantly improve the As(III) removal capacity of ZVI/Sch mixture without altering the As(III) removal pathway, including the adsorption/precipitation/oxidation processes of ZVI and surface complexation/ion exchange/channels inlay of Sch. These findings shed light on the complex interactions between ZVI and Sch in As(III) removal and offer promising opportunities for the development of efficient treatment strategies in As(III)-contaminated environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dendritic fiber nanosilica (DFNS) based fluorescence sensor was prepared. • FL-DFNS functions as a "turn off" sensor for Hg2+/Hg + ions. • FL-DFNS/CSPU membrane enabled portable detection of Hg2+/Hg+ ions. • FL-DFNS/CSPU membrane exhibited superior separation of Hg2+/Hg+ performance. Dendritic fiber nanosilica (DFNS) possesses a unique porous structure, and its potential application for adsorption and separation, particularly of heavy metals, should be explored. This study, to our knowledge, is the first time to introduce fluorescence recognition ability to DFNS and to combine it with polymer materials. Firstly, the fluorescent DFNS (FL-DFNS) was prepared by a Schiff base formation reaction between the naphthalamide fluorophore and the modified DFNS. Then, a two-step approach was employed to fabricate FL-DFNS/polyurethane (FL-DFNS/CSPU-02) nanocomposite materials. FL-DFNS functions as a "turn off" sensor for Hg2+/Hg+ ions, exhibiting fluorescence quenching of up to 81.1 %/75.9 %. It also has an excellent adsorption capacity to mercury. Specifically, FL-DFNS/CSPU-02 membrane enabled portable detection of Hg2+/Hg+ ions. Importantly, it exhibited superior performance in the adsorption and separation of Hg2+/Hg+ ions, achieving a removal efficiency of 97.7 % and 98.0 %, with an absorption capacity of 382.4/373.5 µg/cm2. And it can be recycled for at least nine times. Overall, this study confirms the practical application value of FL-DFNS and FL-DFNS/CSPU-02 membrane in the recognition and removal of Hg2+/Hg+ ions, it will achieve the real application in environmental science and engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] • CMC@HMMOF aerogel was synthesized by an Ex-situ method. • CMC@HMMOF-Cys/PPL aerogel exhibited high PAT adsorption capacity of 38.41 μg/mg. • CMC@HMMOF-Cys/PPL aerogel could be used in a flow reactor. • This system possessed an excellent application potential of apple juice samples. Patulin (PAT) is a mycotoxin synthesized by fungi such as Penicillium expansum. It has become a key risk indicator in fruit juices and therefore needs to be removed. Here, we used an ex-situ method and a self-assembly strategy to prepare a green carboxymethyl cellulose@hierarchical mesoporous zirconium metal–organic framework-cysteine/porcine pancreatic lipase (CMC@HMMOF-Cys/PPL) aerogel for the safe and efficient removal of PAT from apple juice. The optimal CMC@HMMOF-Cys/PPL aerogel exhibited high adsorption capacity (38.41 μg/mg), excellent degradation capacity (28.68 μg/mg at 10 μg/mL PAT), good reusability and storage stability, and improved selectivity. Notably, it could be customized as a filler for flow reactors to achieve the safe and efficient removal of PAT from apple juice. More importantly, the CMC@HMMOF-Cys/PPL aerogel designed did not have a significant effect on the quality of apple juice. The present study provided a new method for removing PAT from apple juice and further expanded the real-world applications of MOFs. [ABSTRACT FROM AUTHOR]

[Display omitted] • OA with 8 carbons provides better adsorption capacity through steric hindrance. • –COOH competes between OA/H 2 bpydc and H 2 bpdc to bind Zr cluster to form defects. • L-cysteine modification introduces more adsorption sites such as –COOH and –SH. • Easy recyclability and separation of aerogel beads were provided. • Adsorption capacity for Pb2+, Cd2+ and Cu2+ increased by 66.2, 10.7 and 5.8 times. Threats caused by heavy metal ions have prompted people to develop porous and functionalized materials to remove them. Metal–organic frameworks (MOFs) show potential for heavy metal ions removal due to the high specific surface area, tunable pore size, flexible designability and favorable stability. However, the intrinsic microporous structure and powder form limit their applications. Herein, we designed a shapeable aerogel bead incorporated with L-cysteine-modified defective UiO-67 for Pb(II), Cd(II) and Cu(II) adsorption. The pristine UiO-67 powders were firstly modified by introducing the modulator (octanoic acid) and an extra ligand (2,2′-bipyridine-5,5′-dicarboxylic acid) to construct defects, both of them competed with the original ligand to coordinate to Zr clusters, resulting in an increased BET surface area (from 337.66 to 1,037.14 m2/g) and mesoporous ratio (from 34 % to 74 %) of the pristine UiO-67. Then, the graft of L-cysteine containing –COOH and –SH introduced more active adsorption sites. Moreover, the powder material was incorporated into sodium alginate aerogel beads which enhanced the recyclability and further improved the adsorption capacity for Pb(II), Cd(II) and Cu(II). These appealing advantages endow the adsorbent with quicker adsorption equilibrium (240 min), and outstanding removal capacities for Pb(II) of 661.2 mg/g, Cd(II) of 296.2 mg/g and Cu(II) of 326.4 mg/g. The chelation and ions exchange between the numerous functional groups including –COOH, –OH and –SH and the heavy metal ions are the main mechanisms for effective adsorption. This work provided a novel approach for the application of MOFs in environmental remediation. [ABSTRACT FROM AUTHOR]

Loading metal oxide nanoparticles (NPs) into porous granular materials with excellent hydraulic characteristics offers a promising option to break the technical barriers of direct application of NPs in scaled-up water decontamination. By taking advantage of graphene oxide (GO) mediating the formation of manganese oxide (MO) nanoparticles at the same time aggregating to form macroporous structure under highly alkaline conditions, we fabricated a novel GO-MO composite (D = ∼160 μm). The intraparticle diffusivity of Cd(II) and Cu(II) onto GO-MO was determined to be 3.17 × 10 −9 and 4.67 × 10 −9  cm 2  s −1 , respectively, similar to macroporous resin. The GO-MO showed synergistic sorption capacity for Cd(II) and Cu(II) compared to bulky MO and GO due to the high dispersion of MO NPs (<10 nm) in the aggregated GO matrix and Donnan membrane effect. The GO-MO also had strong sorption selectivity in the presence of Ca(II) and humic acid. HADDF-EDS characterization visually showed that Cu(II) and Cd(II) was selectively adsorbed to MO even in the presence of 50 times higher competing Ca(II) ions, which was quantified as ∼93% of the total adsorbed metal for both Cu(II) and Cd(II) by XPS analysis. Moreover, GO-MO was successfully employed in the column operation with effective treatment volume of ∼1650 and ∼1995 BV for simulated Cd(II)- and Cu(II)-contaminated wastewater, respectively. The exhausted GO-MO can be effectively regenerated using acid-salt binary solution with desorption rate >97%. The results from this study may offer insights to rationally design highly efficient engineered nanocomposites for water purification. [ABSTRACT FROM AUTHOR]

Cesium generated from nuclear power plants is the primary source of problems for human health and environment due to its gamma radiation and high fission yield. Among the cesium removal methods, adsorption is an effective way to separating it from water. The abundance, retrievability, and selectivity of an adsorbent are crucial for its practical application in wide areas. Herein, we report a simple and environment-friendly synthesis of montmorillonite-prussian blue (MMT-PB) hybrid adsorbents and studies of the kinetic and equilibrium adsorption. Even though chemisorption (ion exchange) was dominant, physisorption (ion trapping) also occurred especially for the MMT-PB hybrid. The maximum adsorption capacity of MMT-PB was 57.47 mg/g, which was high enough as compared favorably with that of previously reported adsorbents. The distribution coefficient ( K d ) of the hybrid was examined in the presence of prevalent cations such as Na + , K + , Ca 2+ , and Mg 2+ to analyze its selectivity. The K d value ranged from 3680 to 13700 mL/g at a cation concentration of 0.001 M. Moreover, the divalent cations prevented cesium adsorption due to its high electrostatic interactions with the adsorbent. The K d decreased, ranging from 973 to 4160 mL/g, at a cation concentration of 0.1 M. In this case, K + significantly prevented cesium adsorption as their hydrated radii are similar. Considering the low concentration of K + in nature, the MMT-PB hybrid shows great promise for large-scale application in cesium removal from soil and contaminated water. [ABSTRACT FROM AUTHOR]

We recently demonstrated common oxidants simply coupled with ZVI to continuously drive the accelerated Fe 0 corrosion and hence achieve fast and very efficient removal of heavy metals and metalloids from groundwater. In this study, we aimed first to answer a basic question of the oxidant dosage theoretically required to sequester a certain amount of selenite. The specific ratio of oxidant dosage to Se(IV) removal, which reflected the theoretically minimal oxidant dosage required to sequester one mole of Se(IV), was almost independent of the initial Se(IV) concentration but significantly affected by the difference in oxidant species. To sequester one mole of Se(IV), the minimum dosage of the required oxidant was calculated to be 3.94–4.09 for NaClO, 3.90–4.33 for H 2 O 2 , and 3.29–3.54 for KMnO 4 , respectively. Simultaneous aeration increased the removal efficiency of Se(IV) and substantially reduced the required dosage of oxidants. To form a strong contrast with very limited Se(IV) removal by ZVI alone, the coupling of NaClO and H 2 O 2 into the ZVI system remarkably enhanced the performance of Se(IV) removal during the long term fixed-bed experiments with a real groundwater background. The ZVI columns coupled by NaClO and H 2 O 2 steadily treated 10,000 volumes (BV) of real groundwater. X-ray adsorption near edge structure (XANES) demonstrated that more than 85% of the selenium was reduced to Se 0 and Se 2− , with Se 0 as the dominant selenium species sequestered in the solid phase. Synchrotron-based scanning transmission soft X-ray microscopy (STXM) explicitly revealed the ubiquitous spatial distribution of selenium in the corrosion products and hence demonstrated a high accessibility of these corrosion products to selenite. [ABSTRACT FROM AUTHOR]

A novel nanocomposite, named as ARWZ, was fabricated using zero-valent iron (ZVI) nanoparticles supported by acid-modified waste rock wool (ARW). ARW displayed a porous rod-like structure and could load plenty of ZVI nanoparticles. Meanwhile, ARW could effectively inhibit the aggregation and oxidation of ZVI nanoparticles because of steric-hindrance effect. ARWZ exhibited a large specific surface area and high removal capacity (197.69 mg/g) in 30 min for hexavalent chromium (Cr(VI)) from water and soil through adsorption and reduction, and the resulting ARWZ-Cr could be easily collected under a magnetic field because of the superior magnetic property. Importantly, when ARWZ was loaded in filter cotton with a micro/nano networks structure, the resulting system could be conveniently used as an excellent filter layer to control the migration of Cr(VI). This work provides a low cost and promising approach to remove Cr(VI), which also promotes the reuse of waste rock wool. [ABSTRACT FROM AUTHOR]

Developing highly uniform and compact metal-organic frameworks (MOFs) membranes grown on flexible substrate such as cloth for highly efficient heavy metal removal is an appealing yet challenging task. Herein, we demonstrate a facile route to rapidly in situ synthesize Zn/Co-ZIF crystals onto cloth to form robust and compact MOF membranes at room temperature. Carboxymethylcellulose sodium (CMC) is introduced to act as a macromolecule bridge to promote the chemical surface attachment of Zn/Co-Zeolite Imidazolate Frameworks (Zn/Co-ZIF) crystals while simultaneously impeding solution-phase crystal agglomeration. SEM, XRD and FT-IR spectra were used to characterize the CMC-MOF/Cloth composite membranes. Benefiting from the intrinsic properties of Zn/Co-ZIF, the CMC-MOF/Cloth shows remarkable selectivity and excellent adsorption capacity (862.44 mg g −1 ) toward Pb(II). Detailed adsorption behaviour and mechanism are revealed by batch sorption runs with Pb(II) and a series of structural characterizations, respectively. In addition, the CMC-MOF/Cloth composite membranes can rapidly decontaminate the concentration of Pb(II) with good removal efficiency using a filtration apparatus, as well as exhibit splendid reusability for multiple regeneration cycles, which demonstrate the CMC-MOF/Cloth composite membranes, being as an efficient, low-cost, easy-obtained, and environmental-friendly MOF-based membranes, possesses great potential for the removal of Pb(II) in water purification. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide-based 2D nanomaterials have become an attractive target for investigations in various fields. However, their potential application in the important area of environmental science has not yet been effectively explored. In this work, ultrathin molybdenum disulfide nanosheets decorated with cerium oxide nanoparticles (MoS 2 /CeO 2 ) nanohybrids were synthesized using a two-step hydrothermal reaction and used to remove Pb 2+ as a representative heavy metal ion. A detailed characterization, including transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectrum, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA), confirmed the formation of the MoS 2 /CeO 2 nanohybrids. Furthermore, different factors affecting the sorption process, such as pH, adsorbent amount, contact time, ion strength, and reusability, were studied in detail. The adsorption kinetic data were described well with the pseudo-second-order model, and the equilibrium data were fitted well to Langmuir isotherms. The as-prepared nanohybrids exhibited a high uptake ability (333 mg g −1 at pH 2.0) and excellent reusability. More importantly, hybrid materials showed preferential Pb 2+ uptake behaviour compared to other heavy metal ions such as Cd 2+ (3.24 mg g −1 ), Cu 2+ (5.3 mg g −1 ), Zn 2+ (3 mg g −1 ), Co 2+ (1.8 mg g −1 ), Ni 2+ (1.3 mg g −1 ), Mn 2+ (2.1 mg g −1 ), and Cr 3+ (1.76 mg g −1 ). The adsorption mechanism may be attributed to the intrinsically sulfur-rich characteristic, the strong soft-soft interactions between S atoms and Pb atoms, the interlayer spacing capture, and weak ion-exchange interaction. These findings open the possibility of expanding the applications of transition metal dichalcogenide-based materials in the environmental sciences. [ABSTRACT FROM AUTHOR]

A magnetic ceramsite (MC) coated by nano carbon spheres (MCCS) was fabricated, and then the MCCS was stabilized and functionalized by polyethylenimine (PEI) to obtain a nanocomposite named as MCCSP. The nano carbon spheres (NCS) possessed plenty of amino and oxygen-containing groups ( OH, COOH) and distributed homogeneously on the surface of MC, meanwhile the size and dispersion of these NCS could be conveniently adjusted. MCCSP demonstrated a high adsorption capacity for Cr(VI) which could be then reduced to low toxic trivalent chromium (Cr(III)), and the obtained Cr(III) could be chelated on the surface of MCCSP by protonated amine groups. Importantly, the resulting MCCSP-Cr could be conveniently collected from water and soil by a magnetic separation system (MSS). Therefore, this work provides a promising approach to remediate Cr(VI)-contaminated water and soil and may have a high application value. [ABSTRACT FROM AUTHOR]

Nanoscale zero-valent iron (nZVI) is very efficient in removing chlorinated nitroaromatic antibiotic chloramphenicol (CAP) from different waters including DI water, surface water, groundwater, and seawater. The corrosion of nZVI and product distribution after reaction in these water matrices were also investigated. Based on the identification of four main reduction products via HPLC, UPLC-MS/MS, and NMR-H spectrums, a more detailed pathway of CAP degradation by nZVI was proposed than ever reported. The two O atoms on the NO 2 group were successively reduced first, and then two Cl atoms were removed via dechlorination. The process of CAP removal could be divided into two stages according to the pseudo-first-order kinetic model. A total of 97.0% of 0.30 mM CAP was rapidly removed by 1.8 mM nZVI in the first stage (6 min) with a surface-area-normalized reaction rate of 1.13 L min −1 m −2 . Notably, after reaction with nZVI, the antibacterial activity of the CAP solution was greatly reduced. This study demonstrates that nZVI is a promising alternative to remediate CAP-contaminated water to reduce the antibiotic selection pressure of the environment. [ABSTRACT FROM AUTHOR]

A novel cobalt(II) ion-imprinted polymer (Co(II)-IIP) was synthesized and characterized by X-ray diffractometer (XRD), Fourier transform infrared spectrum (FT-IR), Energy dispersion X-ray spectroscopy (EDS) and N 2 adsorption–desorption experiments. Batch experiments were conducted to evaluate its removal performance towards Co(II). The polymer exhibited an excellent adsorption ability on Co(II) with a saturation adsorption capacity of 175 mg g −1 , which is almost the highest adsorption capacity of ion-imprinted adsorbents on cobalt(II) ion until now. Moreover, there is an encouraging selectivity to other coexisted heavy metal ions. In particular, the selectivity coefficient of Co(II)-IIP to Nickel ( k (Co/Ni)Co(II)-IIP = 4.17) is far more than that of the non-ion imprinted polymer (NIP, k (Co/Ni)NIP = 0.74), which implies that the synthetic imprinted material is successful, and the cobalt(II) ions play the role of a template function. This work provides the first example of an ion-imprinted polymer induced by MOFs, which will introduce new opportunities to the functionalization of MOFs to remove heavy metal ions and radioactive nuclides. [ABSTRACT FROM AUTHOR]

In this work, magnetic porous nitrogen doped carbon structures containing well-dispersed active Fe nanocrystals (Fe/N-C) are fabricated conveniently via Fe 3+ -mediated polymerization of dopamine as precursor combined with in situ post carbonization process, thus allowing the entire encapsulation of active Fe nanocrystals in the interior. The obtained functional hybrid materials at 700 °C (Fe/N-C-700) show spherical structure, high proportion of metallic Fe nanocrystals, ultrahigh surface area, and easy magnetic separation property, affording excellent U(VI) removal capability (232.54 mg·g −1 ), surpassing the Fe/N-C samples pyrolyzed at different temperatures and nano zero-valent iron. During the adsorption process, effects of water chemistries ( i.e. , reaction time, pH, carbonates concentration and temperature) on U(VI) adsorption on Fe/N-C-700 are full explored, and the well-dispersed Fe nanocrystals play important role in reducing into U(IV). Meanwhile, nitrogen dopant could make function well in the electrostatic interaction and partial reduction of U(VI). The present study demonstrates that Fe/N-C-700 nanospheres derived from Fe-PDA have potential application for the preconcentration and immobilization of U(VI). [ABSTRACT FROM AUTHOR]

Organoclays were used as landfill liners, with added value of its enhanced uptake and retention of hydrophobic organic compounds. In addition, uptake of inorganic anions on organoclays was attributed to the electrostatic interactions between the negatively charged anions and the positively charged surfactant admicelle or bilayer formation on the surface of clays. In this study, interactions between anionic drug diclofenac (DC) and neutral chloramphenicol (CP) and organokaolin (OK) were investigated to seek further expansion of using organoclays to present seepage and leaching of waters containing emerging compounds such as pharmaceuticals. Different preparations of OK had drastic effect on the performance of drug uptake on OK. Under the surfactant bilayer surface coverage, the uptake of DC was fast and followed the Langmuir sorption isotherm. The amount of DC adsorbed far exceeded the anion exchange capacity of the OK, suggesting other interactions besides electrostatic interactions played an important role. On the contrary, the uptake of CP followed a linear sorption isotherm. Zeta potential determination confirmed changes of surface charges, while contact angle measurements showed progressive increases in hydrophobicity as the surfactant loading level increases. Instrumental analyses indicated that the drug uptake was limited to the external surfaces of OK and the sorption of DC involve in the C O functional group. Molecular simulation revealed possible interactions via the amine group for DC sorption. The mechanistic study confirmed the validity of using OK for the uptake of DC and CP from water or leachate, a superior feature pertaining to surfactant modification. [ABSTRACT FROM AUTHOR]

This work reported a facile approach to remove anthracenemethanol (AC), a typical polycyclic aromatic hydrocarbon (PAH), from soil using magnetic ceramsite coated with nanoflower-structured carbon (MCCNC), whose optimal form was named as OMCCNC, fabricated by a one-step hydrothermal process. Therein, the carbon coating self-assembled to form a flower-like fractal structure based on the template of micro-nano flakes on the surface of ceramsite. The nanoflower-structured carbon possessed a high porosity and plenty of oxygen-containing groups and thus could efficiently adsorb AC molecules. After adsorption, the high magnetism of OMCCNC facilitated the continuous separation and collection of OMCCNC-AC from soil using a magnetic separation system (MSS) designed by us. Importantly, the OMCCNC could be reused at least for four times. This work provides a promising approach for removing AC from soil and may have a huge engineering application prospect. [ABSTRACT FROM AUTHOR]

A novel metal-organic frameworks (MOFs) UiO-66-Schiff base was successfully synthesized by post-synthetic modification to investigate the cobalt sorption behaviour in simulated wastewater. The thermodynamic and kinetic parameters demonstrated the sorption process to be spontaneous, endothermic and pseudo-second-order chemisorption. The maximum cobalt sorption capacity of the synthetic MOFs was approximately 256 mg g −1 , and the stable and porous Schiff base-derived material displayed excellent regenerated availability with at least five recycle applications. Moreover, density functional theory (DFT) calculations have been performed to explore the coordination modes between cobalt ions and ligands in UiO-66-Schiff base, which revealed that the Schiff base group could take cobalt (II) from cobalt ions hydrates [Co(H 2 O) 6 ] 2+ and Co-CHES (Co-2-(cyclohexylamino)-ethane sulfonic acid) complex [Co(CHES)(H 2 O) 5 ] + to form [CoL N (H 2 O) 5 ] 2+ or [CoL O (H 2 O) 4 ] + . This study offers a facile approach for developing Schiff base modification MOF sorption of cobalt (II) ions from aqueous solutions and provides theoretical and practical guidance on new MOF designs for selective removal of radionuclides. [ABSTRACT FROM AUTHOR]

This paper presents ammonia-enhanced oxidation of flumequine (FLU), a representative fluoroquinolone antibiotic, by ferrate(VI) (Fe VI O 4 2− , Fe(VI)). The second-order rate constants ( k ) without ammonia were 9.34 ± 1.04 and 1.16 ± 0.04 M −1 s −1 at pH 8.0 and 9.0, respectively. These values of k increased linearly with the concentrations of ammonia ([NH 4 + ] + [NH 3 ]) and were 50.00 ± 6.20 and 14.42 ± 1.44 M −1 s −1 for 0.01 M ammonia at pH 8.0 and 9.0, respectively. Oxidized products (OPs) of FLU in the presence of ammonia were identified using liquid chromatography-high resolution mass spectrometry. When ammonia was present in the solution, the distribution of OPs changed from the profile of OPs obtained in the absence of ammonia. The quantitative microbiological assays of Fe(VI)-treated FLU solutions using Escherichia coli and Bacillus subtilis indicated that Fe(VI) oxidation could effectively eliminate the residual antibacterial activity of FLU. Removal experiments demonstrate that the presence of ammonia could also enhance the removal of FLU from water containing humic acid, river water, and wastewater. [ABSTRACT FROM AUTHOR]

Six new NiCr layered double hydroxides (LDHs) intercalated with different inter-layer anions, including diphenylamine-4-sulfonate (DPA), dodecyl sulfonate (DS), pentansulfonate (PS), terephthalate (TA), fumarate (FA) and 2-ethylhexyl hydrogenphosphate (EHP), were synthesized and used to removal of Cd 2+ , Pb 2+ , Cu 2+ , and Zn 2+ ions from water samples. The maximum adsorption capacities ( q m ) for the mentioned LDHs based on their inter-layer anions were DPA > DS > PS > TA > FA > DEHP. This observation highlights the key role of the structure of the inter-layer anions in the adsorption behavior of LDHs. The sulfonate-based LDHs showed better adsorption efficiency than carboxylate-based LDHs, and phosphonate-based LDHs showed the lowest adsorption efficiency. Also, at both high and low concentrations of the metal ions, the length of R– groups and the type of functional groups of inter-layer anions play a key role in the adsorption process. Subsequently, DPA-LDH, due to having the highest q m value among intercalated-LDHs, was chosen as an efficient sorbent for the removal of the metal ions from aqueous samples and its selectivity for adsorption of metal ions was investigated. DPA-LDH displayed a selectivity order of Zn 2+ < Cu 2+ <<< Cd 2+ < Pb 2+ for their adsorption, providing good separation of much more toxic metal ions of Cd 2+ and Pb 2+ from Zn 2+ and Cu 2+ . For the highly toxic Pb 2+ and Cd 2+ , enormous q m values as large as 479 and 282 mg g −1 can be obtained, respectively; and these are among the highest q m values reported for Pb 2+ and Cd 2+ sorbents. The very high distribution coefficient ( K d ) values for Pb 2+ (1.99 × 10 8 mL g −1 ) and Cd 2+ (1.99 × 10 7 mL g −1 ), obtained using a V/m ratio of 2000 mL g −1 , place the DPA-LDH at the top of materials known for such removal. [ABSTRACT FROM AUTHOR]

Antibiotic resistance genes (ARGs) in environment have gradually engendered extensive concern recently due to the harm caused to environment and human beings. Wastewater treatment plants are considered as important nodes of ARGs controlling and it is of utmost importance to figure out effects and mechanisms of each process, especially disinfections. In this study, three disinfection processes (ultraviolet, chlorination, and ozone) were used to reduce levels of ARGs in secondary effluents from a municipal wastewater treatment plant. Results indicated that the abundance of ARGs decreased exponentially as the dosage increased during the ultraviolet disinfection treatment ( R 2 = 0.68–0.92). In the 0–5 mg/L available chlorine concentrations, with a contact time of 30 min, the abundance of ARGs decreased linearly as the chlorine concentrations increased ( R 2 = 0.77–0.99). In a 2 mg/L concentration of ozone (O 3 ), the abundance of ARGs had higher removal efficiency, but the removal efficiency was not significantly enhanced by increasing the concentration of ozone. However, an experiment using the DNase I treatment showed that UV and ozone disinfection resulted in apoptosis, and the bacterial DNA was released into the environment; ARGs were mostly found as free DNA in the treated wastewater. These results provide insights into behavior of ARGs during disinfection processes in wastewater treatment plants. [ABSTRACT FROM AUTHOR]

The removal and recovery of o- xylene (a typical volatile organic compounds, VOCs) by silica gel has been systematically investigated by vacuum swing adsorption (VSA) process. Laboratory scale measurements show that the adsorption of o- xylene on silica gels could be significantly enhanced by increasing the height to diameter ratio (H/D) of adsorption bed, the inlet flowrate and o- xylene initial concentration. However, reducing the H/D and desorption pressure or increasing the amount of purging gas are observed to be favorable for the desorption of o -xylene from the silica gels. The optimized operational conditions are determined at 5:1 for H/D, 5 kPa (absolute) of desorption pressure and 0.45 L/min of purge gas flowrate. According to further kinetic fitting and analysis, it is found that the adsorption of o- xylene on this silica gel is film-diffusion control, which could be enhanced by increasing gas flowrate or initial o- xylene concentration. In addition, reducing the particle size of the silica gel is also found to increase the saturation of adsorbed o -xylene in silica gels. A scaled-up integrated VSA setup was applied to confirm the above results, leading to a complete o- xylene removal from the gas (100% removed) with 87% of o- xylene recovered directly as liquid. Based on a rough economic calculation, the VSA shows greater merits than those of traditional thermal treatment and absorption methods, due to its recovered VOCs as products. Additional tests by other aromatic VOCs further approved the feasibility of the VSA using silica gels. These findings indicate that the VSA with air cooling at ambient temperature would be a promising and ‘green’ technology for treating high boiling VOCs. [ABSTRACT FROM AUTHOR]

Adsorption of nitroimidazole antibiotics (NIABs, such as dimetridazole, metronidazole, or menidazole) over metal–organic frameworks (MOFs, in this case, MIL-101(Cr)) was studied in order to examine the possible applications of MOFs in the purification of water contaminated with NIABs. The MOFs, especially after grafting with urea or melamine, effectively adsorbed the NIABs. For example, urea-MIL-101, compared with any reported result, showed the highest adsorption capacity for metronidazole. Based on the adsorption results over a wide range of conditions, a plausible adsorption mechanism could be suggested for the improved performance: H-bonding between NO 2 of the NIABs and NH 2 of the MOF (introduced via grafting with urea or melamine). The MOFs were shown as a promising adsorbent of NIABs because of their high adsorption capability and reusability (which was confirmed with recyclability testing and FTIR). [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe0@SGB-NH 2 composites filled with semi-porous volume Fe0 were successfully prepared. • The content of Fe0 in Fe0@SGB-NH 2 was only 1/28 times that of unmodified Fe0 to reach the same U(Ⅵ) removal rate. • Fe0@SGB-NH 2 exhibited extraordinary selective capture and removal ability for uranium. • The sediment after the reaction of Fe0@SGB-NH 2 and uranium exhibited excellent resistance to the risk of secondary release. Developing a materials to realize the selective adsorption and long-term immobilization of uranium is of great significance for the effective remediation of uranium-containing wastewater. Herein, we half-filled Fe0 into SGB-NH 2 mesoporous channels to prepare a composite of Fe0 and amino-functionalized silica (Fe0@SGB-NH 2), and used to the selective removal of uranium in solution under aerobic conditions. It was found that solutions containing 10 mg/L U(VI) could be purified 98.96% by Fe0@SGB-NH 2 in the presence or absence of Na+, K+, Mg2+, SO 4 2 −, NO 3 −, HCO 3 − and Cl− at pH 5–9. Compared with Fe0, its saturation magnetization decreased from 81.24 emu/g to 0.78 emu/g, while the specific surface area increased from 47.895 m2/g to 504.404 m2/g, successfully preventing the agglomeration and rapid corrosion of Fe0 without reducing its activity. More interestingly, the consumption of Fe0@SGB-NH 2 was only 1/28 of untreated Fe0 when identical uranium removal efficiency was achieved. Further mechanistic studies indicated that U(VI) was firstly selectively captured by amino groups on the surface of the material and then reduction or adsorption in the pore, the long and narrow mesoporous channels reduce the possibility of uranium re-oxidation, thereby significantly reducing its re-release efficiency from 21.5% to only 1.73%. Encapsulation of Fe0 within SGB-NH 2 channels was found to facilitate faster removal rate and higher U(VI) reduction ratio, and reduce uranium re-oxidation, thus benefit the long-term immobilization of uranium in contaminated groundwater. [ABSTRACT FROM AUTHOR]

[Display omitted] • SR-AOP pre-treatment results in high SO 4 2− ions and partial DOC/COD removal. • Post-biofiltration with petroleum coke and sand successfully attenuated DOC/COD. • Anaerobic degradation of organics in peat was followed by methylotrophy in sand. • Slow sulfate removal was potentially linked to C(1)-sulfur compounds metabolism. Fate of dissolved organics and sulfate ions was studied in fixed bed biofilters (FBBs) treating pre-treated oil sands process water (OSPW) in the presence of industrially relevant substrates namely petroleum coke (PC) and sand. For pre-treatment, the solar-activated sulfate radical advanced oxidation process (SR-AOP) was performed using 2.5 and 5 mM peroxymonosulfate (PMS) as a precursor with solar irradiation of 119.5 W h m−2. Excellent degradation of naphthenic acids (NAs) was attained by SR-AOP, attaining 88 % and 97 % total NAs after 9 h of treatment at 2.5 and 5 mM of PMS, respectively. However, the treatment increased the toxicity due to byproducts and metabolites following the poor removal of dissolved organics, i.e., 13 % and 21.5 %, respectively. Electron paramagnetic resonance spectrometry (EPR) analysis exhibited that hydroxyl radical (⋅OH) and singlet oxygen (1O 2) were the predominant active species produced during SR-AOP. The post-treatment biofiltration improved the mineralization of dissolved organics (45 %) and NAs (99 %) as well as removed the residual toxicity (>80 %). Taxonomy-based transcriptomics analyses (RNA) confirmed the enrichment of microbes involved in the degradation of hydrocarbons and carboxylic acids, methylotrophy, and potentially C(1)-sulfur compounds metabolism. Scanning electron microscopy with energy-dispersive X-ray spectroscopy indicated the potential of PC to support sulfur deposition, but at slower rates. This study indicates that the produced water can be efficiently reclaimed by using advanced oxidation and biofiltration approaches. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antibiotic resistance genes are frequently detected in diverse natural environments. • Nanomaterial-based technologies can eliminate antibiotic resistance to some extent. • Antibiotic resistance elimination involves antibiotics reduction, ARB inactivation and ARGs removal. • Nanomaterials have both positive and negative effects on the horizontal transfer of ARGs. • The tradeoff between nanomaterials-mediated ARGs elimination and dissemination are proposed. Antibiotic resistance has become an emerging global health concern in recent years. Particularly, antibiotic resistance genes (ARGs) are frequently detected in high abundance in various environmental media. A comprehensive understanding of the effects of exogenous compounds on their environmental fates is therefore urgent. Herein, we systemically elaborate on the influence of nanomaterials on the removal and horizontal gene transfer (HGT) processes of ARGs. We first introduce the occurrence, behavior, and potential hazards of ARGs, then summarize nanomaterials-mediated antibiotic resistance removal, covering antibiotic reduction, microbial inactivation and ARGs elimination, next elaborate the influence of nanomaterials on the HGT processes of ARGs along with the involved mechanisms, and last point out the tradeoff between ARGs elimination and horizontal transfer by nanomaterials. The present review could strengthen our understanding of the nanomaterials-mediated dissemination of antibiotic resistance, thus undoubtedly alerting us to rethink the reasons for the spread of ARGs apart from antibiotic contaminants and to reevaluate the potential detriment of nanomaterials on the prevalence of ARGs in complex ecological environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mesoporous silica-based solid acid was synthesized in the absence of template. • High surface silicon exposure supplied large amount of surface groups to be available. • Acetaldehyde was removed (above 99.99 %) from ethanol through a novel strategy of "waste to value". • The remaining acetaldehyde was controlled to be below 0.01 ppm with a wide range of concentration. In the absence of any template, mesoporous silica-based solid acid owing a high surface area (380.2 m2/g), big average pore size (5.6 nm), and moderate acid amount (1.33 mmol/g) was synthesized through a one-step reverse-phase microemulsion method. The introduction of 3-sulfopropyl as the acidic sites by this method increased the surface silicon exposure to a high value of 74.1 %, which enabled plenty of active groups to be available on the surface. As the main impurity in ethanol and has the potential to cause the serious damage for people's health, acetaldehyde was removed with high removal (above 99.99 %) from ethanol through a novel strategy of "waste to value" with the present acid catalyst at the ambient temperature, in which acetaldehyde was converted to a much safer chemical of acetal that owns a pleasant odor and is permitted to be used as the fragrance in food. The remaining acetaldehyde could be controlled to a very low and much safer level of below 0.01 ppm with a wide range of initial concentration. [ABSTRACT FROM AUTHOR]

An improved electrokinetic (EK) process for the removal of copper and nickel from municipal sludge was investigated using a custom-made experimental setup. Optimal parameters were identified as an HNO 3 electrolyte concentration of 0.200 mol/L in the anode chamber; NaNO 3 electrolyte concentrations of 0.800 mol/L in the heavy-metals and cathode chambers; and a current density of 2.0 mA/cm 2 . Adjustment of the sludge pH to 3.8 before treatment clearly increased the current efficiency (CE) and decreased the specific energy consumption (SEC) of the process. Under the optimal conditions in EK systems equipped with two and three sludge chambers, the removal efficiencies for copper and nickel were 51.5–82.9% and 46.6–75.1%, respectively, after 132 h. The results of a sequential extraction procedure revealed that the binding states of the metals in the sludge were changed from difficult-to-extract to more easily extractable states after the EK process. Energy consumption calculations showed that the CE increased to 137.8% and the SEC decreased to 2.39 kWh/kg of metals removed when three sludge chambers were equipped in the EK system. A mechanistic analysis of the current method demonstrated that it can be regarded as an effective technique for removing metals from municipal sludge. [ABSTRACT FROM AUTHOR]

Two novel nanocomposites have been designed and synthesized using simple and green functionalization of nanosilica sorbent with nanopolyaniline and crosslinked nanopolyaniline, [Sil-Phy-NPANI] and [Sil-Phy-CrossNPANI]. The images of scanning electron microscopy (SEM) and high resolution transmission electron microscope (HR-TEM) confirmed the immobilization process and particle size in the range of 7.14–23.91 nm. The two novel nano-structured silica composites have been further confirmed and evaluated by determination of surface area, Fourier transform-infrared (FT-IR) study and thermal gravimetric analysis (TGA). The sorption characteristics of [Sil-Phy-NPANI] and [Sil-Phy-CrossNPANI] versus nanosilica were compared toward Cu(II), Cd(II), Hg(II) and Pb(II) ions and investigated by the batch technique in presence of different pH values, contact times, composite dosages, initial metal ion concentrations and interfering ions. The optimum sorption conditions of these metal ions were identified in pH 6.0 or 7.0 as a result of complexation or ion exchange of the metal ions by surface amine and/or hydroxyl groups. The highest metal capacity values of Cu(II), Pb(II), Hg(II) and Cd(II) were characterized in the ranges 1650–1700, 900–1450, 800–1050 and 600–1350 μmol g −1 , respectively. Fast equilibrium time was obtained (15–20 min) for sorption of the target metal ions. The sorption behaviors of metal ions by [Sil-Phy-NPANI] and [Sil-Phy-CrossNPANI] were reflected by Langmuir and Freundlich isotherm models. The designed nanocomposites were successfully applied for adsorptive removal of Cu(II), Cd(II), Hg(II) and Pb(II) from drinking tap water, sea water and wastewater samples with excellent recovery values. [ABSTRACT FROM AUTHOR]

Though previous studies have focused on the removal of polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (OPAHs) in wastewater treatment plants, there is a lack of information on the transformation from PAHs to OPAHs during the activated sludge treatment. In this study, a batch experiment was carried out to simulate the aerobic biological treatment process, and the fungi species was detected by high-throughput sequencing. In the result, the transformation from PAHs (anthracene) to OPAHs (anthraquinone) was confirmed. A higher temperature (25 °C/35 °C) and higher initial concentration (5.0 μg/L) of anthracene promoted the formation of anthraquinone, compared with a lower temperature (10 °C) and lower initial concentration (0.5 μg/L). The relevant functional fungi for the transformation were detectable in the activated sludge ( Candida_parapsilosis , Candida_tropicalis and Bjerkandera -sp), confirming the biotransformation. After 168 h, anthraquinone was totally biodegraded, indicating that activated sludge treatment was satisfactory for PAHs removal from the aspect of the biodegradation of the intermediate OPAHs. Furthermore, the possible factors influencing the biodegradation of both PAHs and OPAHs were also determined. The lower molecular weight compounds were more easily biodegraded than the higher ones. The temperature around 25 °C was more appropriate for compounds removal than 35 °C or 10 °C, because the microbial species were more plentiful in activated sludge at 25 °C. Different initial concentrations (0.5 μg/L, 5.0 μg/L) did not significantly influence the removal efficiency. However, the compounds we added to the samples could be more easily removed than those inherent in the samples, probably resulting from the stronger combination of the inherent compounds with the dissolved organic matters. The results from the batch experiment could be valid indicators for the effect of real wastewater treatment process. [ABSTRACT FROM AUTHOR]

Rejection behavior of five kinds of phthalate acid ester (PAEs) including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di-n-octyl phthalate (DnOP) and diethylhexyl phthalate (DEHP) from water sources using lab-fabricated hollow fiber nanofiltration (NF) membranes were investigated. Adsorption kinetic behaviors of PAEs were studied as well as the different operation parameters on the rejection of PAEs. The results showed that the times in which PAEs reach saturation adsorption on membrane surface are different. The equilibrium time increased with the molecular weight of the PAE increase. After the PAE reached adsorption equilibrium, the rejection rates of DMP, DEP, DBP, DnOP and DEHP by NF membranes were 82.3%, 86.7%, 91.5%, 95.1% and 95.4%, respectively. The influence of operation parameters including the operation pressure, pH, ionic strength, and temperature on PAE rejection behaviors were also studied. [ABSTRACT FROM AUTHOR]

A novel preconditioning process using the combined effect of acoustic agglomeration and vapor condensation for fine particles removal with high efficiency was presented. The effect of operation parameters on the enlargement and removal of fine particles were investigated experimentally. Particle size distribution and number concentration with and without external fields were measured by Electrical Low Pressure Impactor (ELPI). The results showed that the stage removal efficiency of fine particles was about 10–23% by acoustic agglomeration only with sound pressure level (SPL) of 150 dB. However, it was significantly improved by the combined effect of acoustic agglomeration and vapor condensation, reaching up to 53–80% with a SPL of 150 dB and supersaturation degree ( S ) of 1.2. Fine particle entrainment factor in acoustic field increased with the supersaturation degree, as well as the removal efficiency. While the supersaturation degree was lower than 1.0, the removal efficiency was extremely low, and increased slightly with the supersaturation degree. However, removal efficiency increased with the supersaturation degree rapidly when the supersaturation degree was higher than 1, which was improved by about 50% as the supersaturation degree increased from 1.0 to 1.4. The coupling external fields cannot be formed when the supersaturation degree was lower than the critical one, resulting in low removal efficiency. Removal efficiency was increased substantially to 63% in the supersaturation degree of 1.2, even in a low SPL of 130 dB. It indicates that high removal efficiency can be obtained in the combined effect of acoustic agglomeration and vapor condensational growth even in low intensity acoustic field. [ABSTRACT FROM AUTHOR]

The SO 3 removal properties were investigated in the wet flue gas desulfurization (WFGD) system. The relationship of the aerosol emission properties and the SO 3 concentration in the flue gas was explored experimentally based on the ammonia desulfurization system. The impacts of the operating parameters, such as the liquid-to-gas ratio (L/G), the flue gas temperature, the superficial velocity, and the particle concentration in the flue gas on the SO 3 removal efficiency were studied. The results showed that when the SO 3 concentration in the flue gas increased, the aerosol emission concentration was higher although the aerosol sizes became smaller within the measurement range of the electrical low pressure impactor (ELPI). When the SO 3 concentration was 12 mg/Nm 3 and 47 mg/Nm 3 , respectively, the aerosols emitted from the WFGD system showed the similar morphologies. Under the same operating conditions, the SO 3 removal efficiencies in the ammonia-based WFGD system were higher than those in the limestone–gypsum WFGD system, both of which rose with the increase of SO 3 concentrations. In the ammonia-based WFGD, the SO 3 removal efficiency would be improved when the L/G and the particle concentration in the flue gas were raised and the flue gas temperature and the superficial velocity were reduced. Two SO 3 removal mechanisms were proposed in the ammonia-based WFGD processes. One was the collision trap mechanism and the other was the heterogeneous reaction mechanism. The sulfuric acid aerosols formed though the quenching process of hot flue gas were measured to be mainly submicron particles. For the removal of these particles, the Brownian diffusion was proved to be the predominant removal mechanism in the collision trap processes, rather than the inertial impaction. [ABSTRACT FROM AUTHOR]

Chemical reduction technology based on nanoscale zerovalent iron (NZVI) is an effective method for in-situ remediation of Cr(VI)-polluted water. However, it is difficult to overcome the associated surface passivation during the reaction process, thus losing the reduction reactivity. In this study, a novel system based on the NZVI/graphene nanosheets (NZVI/GNS) is constructed for the effective removal of Cr(VI) in water. Immobilization of NZVI onto graphene improves the stability of the NZVI, while graphene coupling facilitates the electron transfer in the NZVI and retards the surface passivation of the NZVI, thus enhancing the performance of the NZVI toward Cr(VI) removal. The NZVI/GNS exhibits significantly higher activity toward Cr(VI) removal than that of bare NZVI. The Cr(VI) removal efficiency is closely correlated to the graphene amounts in the NZVI/GNS. Based on X-ray photoelectron spectroscopy (XPS) and steady-state polarization measurements, the mechanism of Cr(VI) reduction reaction with the NZVI/GNS has been unraveled as well. [ABSTRACT FROM AUTHOR]

Novel hybrid strong anion exchange porous carbon fibers (HACAX) were synthesized and evaluated for adsorption of low concentrations of Cr(VI) at natural pH. Positive surface charge due to pyridinium groups enables HACAX to adsorb Cr(V) rapidly and with high capacity. HACAX showed stable and regenerable performance for adsorbing and converting Cr(VI) into Cr(III) with no change in pH, which is attributed to the catalytic activity of surface oxygen functional groups. [ABSTRACT FROM AUTHOR]

We report on the facile, reliable fabrication of novel magnetic cucurbit[6]uril/graphene oxide (CB[6]/GO/Fe 3 O 4 ) composite by using an in-situ co-precipitation method, for which the formation process and possible formation mechanism were also investigated. Moreover, the composite was used as an adsorbent for the removal of uranium(VI) from aqueous solution. Herein, GO nanosheets were chosen as a substrate to immobilize CB[6] and Fe 3 O 4 . During the co-precipitation of Fe 3 O 4 nanoparticles on surface of GO nanosheets, CB[6] molecules was fixed through hydrogen bonding simultaneously. The as-prepared composite exhibited a high efficiency of magnetic separability, competitive adsorption performance and acceptable reusability and stability for U(VI) removal, indicating a potential application in uranium-bearing wastewater treatment. [ABSTRACT FROM AUTHOR]