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High-salinity textile wastewater is a pressing environmental concern, urgently requiring the appropriate treatment. Sustainable management of high-salinity textile wastewater via fractionation of the existing dyes and inorganic salts (NaCl) using selective separation membranes is a key approach to address this detrimental concern. Herein, tight composite ultrafiltration membranes with impressive antibacterial function were constructed using one-step co-deposition of dopamine and tobramycin on the porous substrate to fractionate the dyes and NaCl. Triggered by ammonia persulfate, the polydopamine/tobramycin coating layer imparts the fabricated composite ultrafiltration membranes with tight surface structure and narrow pore size distribution, enabling effective dyes/salts fractionation. Specifically, the tight composite ultrafiltration membrane with a molecular weight cutoff of 3692 Da experienced a > 98.0 % rejection against various reactive dyes (molecular weight: <1000 Da) with nearly complete salt transmission (<0.8 % NaCl rejection), demonstrating an effective fractionation of dyes and salts. Additionally, the incorporated tobramycin as a broad-spectrum antibiotic endowed the tight composite ultrafiltration membrane with a sufficient inhibition efficiency (i.e., 100 %) against E. coli bacteria in a short-time contact (i.e., 3 min). Thereby, the tight composite ultrafiltration membrane constructed by fast co-deposition of dopamine and tobramycin established an unparalleled platform technology for sustainable resource recovery (dyes or salts) from high-salinity textile wastewater. [Display omitted] • Tight ultrafiltration (UF) membrane with 3692 Da MWCO was designed by rapid co-deposition of dopamine and tobramycin. • Tight UF membrane had an impressive rejection of >98.0 % for various reactive dyes with >99.2 % NaCl transmission. • Tight UF membrane showed a robust stability in fractionation of dyes and salts. • Tight UF membrane yielded a 100 % inhibition efficiency against E. coli for mitigating the biofouling. [ABSTRACT FROM AUTHOR]

The hybrid membrane bioreactor - nanofiltration treatment process can be an effective approach for treating the landfill leachate, but the residual leachate concentrate highly loaded with the humic substance and salts remains an environmental concern. Herein, a loose nanofiltration membrane (molecular weight cut-off of 860 Da) was used to recover the humic substance, which can act as a key component of organic fertilizer, from the leachate concentrate. The loose nanofiltration membrane showed the high permeation fluxes and high transmissions (>94.7%) for most inorganic ions (i.e., Na+, K+, Cl−, and NO 3 −), while retaining 95.7 ± 0.3% of the humic substance, demonstrating its great potential in effective fractionation of humic substance from inorganic salts in the leachate concentrate. The operation conditions, i.e., cross-flow rates and temperatures, had more pronounced impacts on the filtration performance of the loose nanofiltration membrane. Increasing cross-flow rates from 60 to 260 L h−1 resulted in an improvement of ca. 7.3% in the humic substance rejection, mainly due to the reduced concentration polarization effect. In contrast, the solute rejection of the nanofiltration membrane was negatively dependent on the temperature. The rejection of humic substance decreased from 96.3 ± 0.3% to 92.0 ± 0.4% with increasing the temperature from 23 to 35 °C, likely due to the enlargement of the membrane pore size and enhancement in solute diffusivity. The humic substance was enriched from 1735 to 15,287 mg L−1, yielding a 91.2% recovery ratio with 85.7% desalination efficiency at a concentration factor of 9.6. The recovered HS had significantly stimulated the seed germination and growth of the green mungbean plants with no obvious phytotoxicity. These results demonstrate that loose nanofiltration can be an effective promising technology to recover the humic substance as a valuable fertilizer component towards sustainable management of the landfill leachate concentrate. Image 1 • Loose nanofiltration (NF) membrane was used for sustainable treatment of leachate concentrate. • Loose NF can effectively separate humic substance (HS) and salts in leachate concentrate. • NF concentration process can significantly enrich and harvest HS with 85.7% salt removal. • The recovered HS stimulated the plant growth, presenting a potential as water-soluble fertilizer. [ABSTRACT FROM AUTHOR]

Abstract Developing a highly efficient, cost-effective, easily scalable and sustainable cathode for oxygen reduction reaction (ORR) is a crucial challenge in terms of future "green" energy conversion technologies, e.g., microbial fuel cells (MFCs). In this study, a natural and widely available lotus leaf with intrinsically hierarchical structure was employed to serve as the single precursor to prepare the catalyst applied as the MFC cathode. The hierarchically particle-coated bio‑carbon was self-constructed from the lotus leaf, which yielded a large specific surface area, highly porous structure and superhydrophobicity via facile pyrolysis coupling hydrothermal activation by ZnCl 2 /(NH 4) 2 SO 4. Electrochemical evaluation demonstrated that these natural leaf-derived carbons have an efficient ORR activity. Specifically, the HC-900 catalyst with hydrothermal activation achieved an onset potential of −0.015 V vs. Ag/AgCl, which was comparable to the commercial Pt/C catalyst (−0.010 V vs. Ag/AgCl) and was more efficient than the DC-900 catalyst through direct pyrolysis. Furthermore, the HC-900 catalyst achieved an outstanding ORR activity via a one-step and four-electron pathway, exhibiting a potential alternative to Pt/C as electrocatalyst in ORR, due to its better long-term durability and methanol resistance. Additionally, the HC-900 catalyst was applied as an effective electrocatalytic cathode in an MFC system with a maximum power density of 511.5 ± 25.6 mW⋅m−2, exhibiting a superior energy harvesting capacity to the Pt/C cathode. Graphical abstract Unlabelled Image Highlights • Lotus leaf-based carbon (HC-900) with hierarchical micro/nanostructure was obtained. • HC-900 has a highly porous structure and super-hydrophobic property. • HC-900 has an efficient and stable ORR activity, outperforming 20 wt% Pt/C catalyst. • HC-900 can be used as effective cathode catalyst for microbial energy harvesting. [ABSTRACT FROM AUTHOR]

In digital printing, a high salt content in dye solutions is detrimental, which calls for effective strategy for dye/salt fractionation. In this study, a loose nanofiltration (NF) membrane Sepro 2A was employed to desalinate diverse dye species (2 reactive dyes and 4 cationic dyes). This membrane, with a molecular weight cutoff of 490 Da, showed consistently high rejections to all the reactive and cationic dyes (>97.7%). Operational conditions such as dye concentrations and applied pressures have limited effects on the rejection of the membrane. An integrated NF-diafiltration process, involving a pre-concentration and a diafiltration step, was specifically designed for the fractionation of dye/NaCl mixtures. This loose NF membrane showed >99.7% rejection to reactive dyes (reactive blue 2 and reactive orange 16) and ca. 99.3% salt removal with ca. 2.0% dye loss after 5.0 diavolumes. However, the NF membrane experienced a 15.9% loss to methylene blue due to the lower rejection to this model cationic dye (97.2%). The current study provides important insights into dye/salt fractionation by loose NF membranes for digital ink-jet printing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Downstream waste-to-hydrogen process can be realised with 2D material-based membrane. • Mechanism and fabrication methods of 2D material-based gas separation membrane are outlined. • 2D COFs, MOFs and carbon-based materials are reviewed for H 2 /CO 2 gas separation membranes. • Challenges and future prospect of 2D material-based membrane in waste-to-hydrogen are discussed. Waste management has become an ever-increasing global issue due to population growth and rapid globalisation. For similar reasons, the greenhouse effect caused by fossil fuel combustion, is leading to chronic climate change issues. A novel approach, the waste-to-hydrogen process, is introduced to address the concern of waste generation and climate change with an additional merit of production of a renewable, higher energy density than fossil fuels and sustainable transportation fuel, hydrogen (H 2) gas. In the downstream H 2 purifying process, membrane separation is one of the appealing options for the waste-to-hydrogen process given its low energy consumption and low operational cost. However, commercial polymeric membranes have hindered membrane separation process due to their low separation performance. By introducing novel two-dimensional materials as substitutes, the limitation of purifying using conventional membranes can potentially be solved. Herein, this article provides a comprehensive review of two-dimensional materials as alternatives to membrane technology for the gas separation of H 2 in waste-to-hydrogen downstream process. Moreover, this review article elaborates and provides some perspectives on the challenges and future potential of the waste-to-hydrogen process and the use of two-dimensional materials in membrane technology. [ABSTRACT FROM AUTHOR]

Nanofiltration (NF) membranes have been used previously for the recovery of dyes, salts, and water from textile wastewaters with high salinity. However, commercially available NF membranes have a high rejection for divalent salts (i.e., Na 2 SO 4 ), substantially reducing the salt recovery and membrane flux when treating textile wastewater containing Na 2 SO 4 . In this study, a tight ultrafiltration membrane (UH004, Microdyn-Nadir) was proposed to fractionate the dye and Na 2 SO 4 in the textile wastewater. The UH004 membrane with a molecular weight cutoff of 4700 Da provided complete passage of monovalent salts, with little rejection of Na 2 SO 4 . This significantly increases the filtrate flux that can be achieved with high-salinity wastewater since osmotic pressure and concentration polarization effects are minimized. Furthermore, the retention behavior of four different dyes was evaluated to determine the efficiency of this membrane process. This tight ultrafiltration membrane offered the high retention for direct dyes (i.e., direct red 80, direct red 23, and Congo red) and reactive blue 2. For instance, the UH004 membrane yielded >98.9% rejection for all of the dyes at a pressure of 4 bar even in the presence of 60 g L −1 Na 2 SO 4 . Subsequently, an ultrafiltration-diafiltration process was designed to separate a dye/Na 2 SO 4 aqueous mixture with 98% desalination efficiency and greater than 97% dye recovery after 5 diavolumes. These results clearly demonstrate that tight ultrafiltration membranes can be a stand-alone alternative to NF membranes for the effective fractionation of dye and Na 2 SO 4 in the direct treatment of high-salinity textile wastewater. [ABSTRACT FROM AUTHOR]

SiO 2 nanoparticles offer promising prospects as additives for the synthesis of organic–inorganic hybrid composite membranes due to their facile synthesis procedure with low cost and toxicity to aqueous systems. This requires silica nanoparticles with good monodispersity to form a regular hydrophilic surface. In this study, monodisperse silica synthesized by the Stöber method was explored as an additive in ultralow concentration for the synthesis of organic–inorganic composite membranes based on polyethersulfone, aiming at potential application in water treatment. The results indicate the polyethersulfone membrane doped with monodisperse silica has an enhanced performance. The hydrophilicity of the modified membranes was also enhanced due to the high water affinity of nano-SiO 2 , resulting in a higher permeability. However, in the high concentration interval of nano-SiO 2 , the permeability of modified membranes decreases due to pore plugging and the alteration of macrovoids in the sublayer of membranes. Simultaneously, the selectivity of the modified membranes was improved, which is an indicator for a more narrow pore size. The optimum permselectivity was obtained with the addition of 0.30% nano-silica. Additionally, the fouling resistance increased by ca. 70%. Thus, doping of nano-silica in the membranes is an alternative method to enhance permselectivity and fouling property for water treatment. [ABSTRACT FROM AUTHOR]

Membrane assisted crystallization (MACr) offers an innovative platform for crystallizing Na 2 CO 3 , allowing its reuse after CO 2 capture from flue gases by an alkaline solution ( i.e. , NaOH). In this study, the biomimetic aquaporin Inside™ membrane AIM60 was employed to enhance water removal, facilitating Na 2 CO 3 crystallization. The water channel in the active layer, comprising aquaporin proteins, and the strong wettability of membrane substrate assist a better performance. For instance, the water flux of AIM60 membrane for concentrating a 1.89 mol L −1 Na 2 CO 3 solution (osmotic pressure of 94.8 bar) in forward osmosis (FO) mode was 6.62 L m −2 h −1 and 3.25 L m −2 h −1 in pressure retarded osmosis (PRO) mode when a 5.13 mol L −1 NaCl solution (osmotic pressure of 304.9 bar) was employed as the draw solution. This demonstrates that the AIM60 FO membrane outperformed the previously reported dense reverse osmosis membrane (0.21 L m −2 h −1 in FO mode and 0.16 L m −2 h −1 in PRO mode) and a porous hydrophobic hollow fiber membrane (0.08 L m −2 h −1 ) under the same operating conditions. Crystallization utilizing the AIM60 membrane in an osmotic crystallizer was achieved without noticeable membrane scaling or degradation. Furthermore, a proper control of the supersaturation level induces crystallization of Na 2 CO 3 ·10H 2 O crystals with a purity of 99.94%. Hence, the aquaporin Inside™ FO membrane may be a promising alternative to existing methods for Na 2 CO 3 crystallization for its application in a CO 2 capture scenario. [ABSTRACT FROM AUTHOR]

Post-combustion CO 2 capture by reaction with a strong alkali such as NaOH appears a promising strategy to mitigate CO 2 emission. This study proposes bipolar membrane electrodialysis (BMED) as a technology for the reclamation of NaOH from glyphosate neutralization liquor and its subsequent use as an absorbent for CO 2 capture. The proposed method produces a NaOH solution for further reaction with CO 2 while recovering the glyphosate from the wastewater. A NaOH solution with a concentration of ∼1.45 mol L −1 and purity of ∼96.5% was obtained. Accordingly, a current efficiency of 80.8%, 76.2%, 68.7% and 69.0% at current densities of 30, 40, 50 and 60 mA cm −2 was observed, respectively. In addition, the lowest energy utilization recorded as 2.15 kW h kg −1 was obtained by the BMED process at a low current density of 30 mA cm −2 , resulting in a better performance in view of energy saving. A glyphosate recovery of ca. 98.2% was also achieved. The environmental impact of the BMED process was evaluated in terms of the amount of CO 2 emissions produced and the total amount of CO 2 captured taking into account of the CO 2 production through BMED process. The results demonstrate that a promising CO 2 capture (up to 530.65 g CO 2 kg −1 NaOH) can be only achieved if the electricity resources originate from renewable sources such as wind, hydroelectric, as well as solar photovoltaics or nuclear energy. However, the utilization of non-renewable energy resources for NaOH production by BMED process imposes a risk on producing a significant emission of CO 2 , which makes the application of BMED unviable for a CO 2 capture scenario. [ABSTRACT FROM AUTHOR]

In the textile industry, high salinity waste streams are a challenge urging for the recovery and purification of dyes and salts (e.g., NaCl), requiring a treatment going beyond the classical filtration by e.g., reverse osmosis to produce pure water. In this work, two commercial loose nanofiltration (NF) membranes (Sepro NF 6 and NF 2A, Ultura) are proposed to fractionate dye/salt aqueous mixtures. It was observed that both NF membranes have a salt rejection <33.3% in solutions with 0.1–40.0 g L −1 of NaCl at 6 bar. Furthermore, both membranes have >99.6% retention of direct dyes (direct red 80, direct red 23, and congo red), even though 40.0 g L −1 NaCl is present, indicating salt addition has no obvious impact on the dye retention. The combination of a low salt rejection and a high dye rejection indicates the feasibility for the reuse of salt from fractionation in forward osmosis and bipolar membrane electrodialysis. Application of diafiltration for an aqueous mixture containing direct red 80 (1000 ppm) and NaCl (~20 g L −1 ) by both membranes demonstrates that above 95% of NaCl is removed from aqueous mixture, and <0.9 g L −1 NaCl remains after the addition of pure water with a volume factor of 4.0 in the feed solution. At the premise of excellent diafiltration performance, concentration as the post-treatment for dye recovery expectedly indicates direct red 80 is concentrated by a factor of 4.0 for both membranes while keeping the salt concentration with a very slight increase. Over 99.9% dye retention in both diafiltration and concentration procedures yields a very high recovery since <0.045% of dye is permeated. These results indicate that loose nanofiltration membranes have potential for dye/salt fractionation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Superhydrophilic g-C 3 N 4 /SiO 2 composite membrane is prepared by vacuum filtration. • The g-C 3 N 4 /SiO 2 composite membrane has effective oil/water separation performance. • Incorporation of g-C 3 N 4 endows the composite membrane with photocatalytic self-cleaning property. • g-C 3 N 4 /SiO 2 composite membrane effectively retains and inactivates the bacteria. Conventional membrane processes, e.g., microfiltration and ultrafiltration, suffer from severe permeation flux decline and fouling during the oily wastewater treatment. The superhydrophilic surface decoration provides an important and effective strategy to address this challenge. Herein, a surperhydrophilic/underwater superoleophobic nanocomposite surface with the photocatalytic properties was constructed via one-step facile vacuum-assisted filtration of a g-C 3 N 4 nanosheet/SiO 2 nanoparticle dispersion onto a microfiltration membrane substrate. Specifically, with the intercalation of 20 mg∙L−1 SiO 2 nanoparticles into the g-C 3 N 4 nanosheets, the g-C 3 N 4 /SiO 2 composite membrane showed the superhydrophilic/underwater superoleophobic properties with an underwater oil contact angle of 170.0 ± 0.3°. Such a g-C 3 N 4 /SiO 2 composite membrane yielded a permeation flux of >1290 LMH·bar−1 with an oil rejection of >99.91% during the vacuum filtration of oil-in-water emulsions. The g-C 3 N 4 /SiO 2 composite membrane significantly outperformed the pristine microfiltration substrate that had severe fouling caused by oil blockage. Additionally, the g-C 3 N 4 /SiO 2 composite membrane not only effectively retained the E. coli bacteria through size exclusion effect, but also promoted the inactivation of bacteria via visible-light photocatalysis. Therefore, our membrane has a great promise in practical oily wastewater treatment due to its excellent separation performance and biofouling resistance. [ABSTRACT FROM AUTHOR]

Membranecontactors have been proposed as an advanced tool for CO2capture from flue gases by absorption in alkaline solutions. However,regeneration of the alkaline reagent and further CO2sequestrationare pending issues. In this paper, membrane-assisted crystallizationis proposed for crystallizing Na2CO3, whichallows its reuse, after CO2absorption from flue gases.Due to the presence of compounds other than CO2in fluegases (i.e., SO2, NOx), othercompounds (Na2SO4and NaNO3) mayinterfere with Na2CO3crystallization. Thiswas evaluated by measuring the flux through the membrane and the morphology,crystallography, and purity of the crystals. Furthermore, the presenceof NaCl possibly transferred from the osmotic solution to the feedsolution was evaluated. The experimental results indicate that thepresence of impurities decreases the flux through the membrane dueto the decrease of water activity, although there is no influenceon the overall mass transfer coefficient. The presence of Na2SO4affected the morphology of the Na2CO3crystals while NaNO3and NaCl had no apparenteffect on the crystalline products. It was confirmed that Na2CO3·10H2O was formed during the crystallization.Moreover, the purity of Na2CO3crystals reachesup to ca. 99.5%. Membrane-assisted crystallization was concluded tobe feasible in recovering CO2as a carbonate salt, whichcan possibly be reused in the industry. [ABSTRACT FROM AUTHOR]

Effective fractionation of dyes and salts (NaCl) potentially paves a new path to sustainable treatment of textile wastewater. Herein, a loose nanofiltration (NF) membrane was innovatively used as the anion conductive membrane in electrodialysis (ED) for dye and salt separation. The NF membrane with a molecular weight cut-off of 678 Da showed a sufficient retention for reactive dyes with small molecular weights (<627 Da) predominantly based on synergistic effect of steric repulsion and Donnan repulsion. Simultaneously, the NF membrane had a considerably fast transport for anions (i.e., Cl−), as its loose surface structure created extra nano-channels for ion transfer. The anion conductive loose NF membrane based ED process yielded excellent separation performance in a one-step dye/NaCl fractionation. Specifically, a 98.9% desalination efficiency was obtained by the loose NF-based ED process along with 99.4% dye recovery. Additionally, an extremely low fouling propensity was observed during a 5-cycle ED operation, as the negative surface charge of the loose NF membrane served as an intrinsic barrier to prevent the dye species from entering the membrane pores through electrostatic repulsion. This study demonstrated a desirable potential of loose NF membranes as anion conductive membranes in ED for resource recovery from highly-saline wastewater. Image 1 1. Loose nanofiltration (NF)-based electrodialysis (ED) was used for dye/salt separation 2. Loose NF membrane shows an excellent ion transport as anion conductive membrane 3. Loose NF-based ED yields 98.9% desalination efficiency and 99.4% dye recovery 4. Low fouling propensity is observed for loose NF membrane as anion conductive membrane [ABSTRACT FROM AUTHOR]

• Mussel-inspired co-deposition was used to effectively tailor the surface property of NF membrane. • The modified NF membrane yielded a molecular weight cut-off of 305 Da after 90-min co-deposition. • The modified NF membrane showed enhanced fractionation of humic substances (HS) and salts. • NF-based diafiltration enriched and purified the HS from landfill leachate concentrate for sustainability. During the disposal of highly saline wastewaters, i.e., landfill leachate concentrate, a conceptual and paradigmatic transformation from contaminant elimination to sustainable resource extraction urges for novel selective membranes. Mussel-inspired modification through dopamine self-polymerization can be a competitive alternative to tailor the membrane surface properties for enhanced permselectivity to target compounds. Herein, co-deposition of polydopamine-polyethylenimine (PEI) complex onto loose nanofiltration (NF) membranes was conducted using persulfate as trigger, which resulted in a significant alteration in membrane surface properties. Particularly, the pore size of bio-inspired NF membranes decreased, along with a reduction in molecular weight cut-off (MWCO) from 640 to 298 Da after 120-min bio-inspired coating, which yielded an enhancement in rejection of humic substances from 95.1% to 98.9% in filtration of landfill leachate concentrate. Furthermore, the charge of membrane surface was tailored to be more positive due to incorporation of positively-charged PEI, which markedly undermined the electrostatic repulsion force for enhanced salt permeation. These bio-inspired NF membranes showed a superior selectivity between humic substances and salts for their potential fractionation from the landfill leachate concentrate. Through an integrated NF-based diafiltration procedure, the concentration of humic substances was remarkably enriched from 1779.4 to 17247.1 mg·L−1 with 96.0% recovery. Additionally, 99.5% desalination efficiency was achieved, resulting in a high purity (i.e., 98.3%) for humic substances as potential organic fertilizer application. These findings suggest that the bio-inspired co-deposition is an effective strategy to tailor the surface properties of NF membranes for efficient fractionation of humic substances and salts, in view of sustainable resource recovery from the landfill leachate concentrate. [ABSTRACT FROM AUTHOR]

• Tight UF membrane with 1700 Da MWCO was designed by rapid co-deposition of PDA/PEI triggered by APS. • Tight UF membrane had an impressive rejection of >98.2% for 6 reactive dyes with >97.0% salt permeation. • Integrated UF-diafiltration enriched reactive blue 4 from 2.04 to 50.70 g·L−1 with 0.9% dye loss. • 99.95% salt removal was obtained by integrated UF-diafiltration with 8 diavolumes. • Tight UF membrane yielded a 90.6% flux recovery by water rinsing, showing a low fouling propensity. Mussel-inspired polydopamine (PDA) coating has received increasing interest in membrane modification for versatile liquid filtration applications, due to its intrinsic adhesion nature. Nevertheless, the bio-inspired PDA deposition initiated by air-oxidation is time-consuming process and generally results in an uneven and unstable coating, which compromises the membrane filtration performance. In this study, the PDA/polyethylenimine (PEI) co-deposition triggered by ammonium persulfate (APS) was conducted to fabricate the tight ultrafiltration (t-UF) membranes with 1000–5000 Da molecular weight cut-offs (MWCOs) for sustainable treatment of highly-saline textile wastewater. APS with strong oxidation capacity can rapidly induce the co-deposition of PDA/PEI layer onto hydrolyzed polyacrylonitrile (HPAN) substrate through the Michael addition or Schiff base reactions, simultaneously minimizing the covalent polymerization of dopamine for PDA aggregation. With 1.5-h coating, a smooth, compact and defect-free PDA/PEI layer with 1700 Da MWCO was evolved on the HPAN substrate, evincing a >98.2% retention for various reactive dyes (610–1000 Da molecular weights) with >97.0% permeation of inorganic salts. In addition, an integrated UF-diafiltration procedure was applied to fractionate the reactive blue 4 (RB4)/NaCl and RB4/Na 2 SO 4 mixtures, enriching the RB4 dye from ca. 2.04 to 50.70 g·L−1 with ca. 99.95% desalination efficiency and ca. 99.2% dye recovery. These results demonstrate that the bio-inspired t-UF membrane through fast PDA/PEI co-deposition is of great promise to sufficiently fractionate the dyes and salts for dye desalination and recovery, realizing the sustainable management of highly-saline textile wastewater. [ABSTRACT FROM AUTHOR]

Loose nanofiltration (NF) membranes can be used to treat textile wastewater effectively, providing an attracted avenue for resource recovery ( i.e., dye purification and salt reuse) at the premise of the integration of high dye retention and salt permeation. However, the issue of membrane fouling has to be adequately addressed in view of its practical application. In this study, superhydrophilic loose NF membranes (Sepro NF 6 and NF 2A, Ultura) were applied for textile wastewater treatment. Synthetic solutions containing dyes and NaCl were used as the feed stream of a NF unit. It was found that two factors, namely cake-enhanced concentration polarization and the formation of a dye cake layer, dramatically deteriorated the flux of NF membranes with a synergic effect. In viewpoint of realistic application, diafiltration of a binary dye/salt mixture indicates that cake-enhanced concentration polarization plays a dominant role for the low membrane flux. As the diafiltration continued, cake-enhanced concentration polarization was alleviated with a decreasing concentration of salt in the feed. At the subsequent post-concentration procedure, the formation of a dye cake layer slightly compromised the membrane flux, but the negative impact of cake-enhanced concentration polarization was negligible due to the small quantity of salt remained in the feed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rapid co-deposition of dopamine and APTS was used to construct superhydrophilic membranes. • Superhydrophilic membrane had an effective oil repellency with underwater oil contact angle of ∼163.5°. • Superhydrophilic membrane has a fast gravity-driven filtration for oil-in-water emulsions with a separation efficiency of >99.9 % • Incorporation of Cu NPs and polydopamine enables the membranes with complete antibacterial activity. Substantial discharge of industrial oily wastewater calls for an efficient and sustainable treatment for resource recovery. Superwetting membranes offer a feasible approach to fractionate oil species and water from oily wastewater for addressing this technical challenge. In this study, we proposed a useful strategy for constructing a superhydrophilic membrane with superior antibacterial properties through rapid co-deposition of dopamine and 3-aminopropyltriethoxysilane (APTS) initiated by ammonium persulfate on the Cu nanoparticles-loaded porous PVDF substrate. The resultant superhydrophilic membrane yielded an underwater oil contact angle of 163.5°, enabling a fast and robust gravity-driven filtration for various oil-in-water emulsions with a separation efficiency of >99.9 %. Additionally, incorporating of Cu nanoparticles and polydopamine endowed the superhydrophilic membrane with superior antibacterial activity (100 % inhibition efficiency against Escherichia coli), and thereby remarkably enhancing the anti-biofouling performance. This study provides a viable approach to design high-performance membranes for separation of oil-in-water emulsions, with promising applications in the industrial and environmental sectors. [ABSTRACT FROM AUTHOR]

Limited information is available on the bioaccessible fraction of trace metals in the resuspended fraction of settled bus dust in order to estimate bus drivers ' occupational exposure. In this study, 45 resuspended fraction of settled dust samples were collected from gasoline and compressed natural gas (CNG) powered buses and analyzed for trace metals and their fraction concentrations using a three-step sequential extraction procedure. Experimental results showed that zinc (Zn) had the greatest bioaccessible fraction, recorded as an average of 608.53 mg/kg, followed in order of decreasing concentration by 129.80 mg/kg lead (Pb), 56.77 mg/kg copper (Cu), 34.03 mg/kg chromium (Cr), 22.05 mg/kg nickel (Ni), 13.17 mg/kg arsenic (As) and 2.77 mg/kg cadmium (Cd). Among the three settled bus dust exposure pathways, ingestion was the main route. Total exposure hazard index (HIt) for non-carcinogenic effect trace metals was lower than the safety level of 1. The incremental lifetime cancer risk (ILCR) for drivers was estimated for trace metal exposure. Pb and Ni presented relatively high potential risks in the non-carcinogenic and potentially carcinogenic health assessment for all drivers. ILCR was in the range of 1.84E − 05 to 7.37E − 05 and 1.74E − 05 to 6.95E − 05 for gasoline and CNG buses, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The application of nanoparticles as additives in membrane synthesis for improving the resistance of membranes against fouling has triggered recent interest in new membrane types. However, most nanoparticle-enhanced membranes suffer from the tradeoff between permeability and selectivity. In this paper, nano-WS2 was explored as the additive in membrane synthesis by non-solvent induced phase separation (NIPS). Blended PES–WS2 flat-sheet membranes with the incorporation of ultra-low concentrations of nanoparticles (from 0.025% to 0.25%, WS2/PES ratio) were manufactured and investigated in terms of permeability, fouling resistance and solute rejection. Remarkably, a significant enhancement in the permeability was observed as a result of the incorporation of ultra-low fractions of nano-WS2 to the membrane structure. The optimum permeability values were obtained for modified membranes with 0.075–0.10% nanoparticle/polymer concentration ratios. In general, fouling resistance and solute rejection were significantly enhanced by the incorporation of nanoparticles into the membrane structure. Specifically, fouling resistance increased by around 50%. [Copyright &y& Elsevier]

Abstract Nanofiltration (NF) has attracted increasing interest for dye and NaCl fractionation in textile industry. However, it typically shows high rejections to divalent salts (i.e., Na 2 SO 4), compromising to effectively purify dye from dye/Na 2 SO 4 mixtures, which is crucial in digital ink-jet printing. This study used a tight ceramic ultrafiltration (UF) membrane (MWCO of 2410 Da) to desalinate diverse reactive dye species with molecular weights from 626.6 to 1205.4 Da. The UF membrane showed considerably high rejections to all the reactive dyes (> 98.12%) and nearly complete salt transmission (rejections < 0.1% and < 1.5% with 60 g L−1 NaCl and Na 2 SO 4 , respectively). Operational conditions, i.e., dye concentration, applied pressure and salt addition, have insignificant impacts on the dye rejection, due to dye aggregation. An integrated UF-diafiltration process, including pre-concentration, diafiltration and post-concentration, was designed to fractionate reactive dyes and Na 2 SO 4. The model dye, reactive blue 19, can be concentrated to 142.60 g L−1 with a purity of 99.83% in the process, since low salt rejection and high dye retention of the membrane allows for 99.88% salt removal and 2.3% dye loss after ca. 9 diavolumes. These results indicate that tight ceramic UF membranes have high potential as a state-of-the-art technology in reactive dyes and Na 2 SO 4 fractionation for digital ink-jet printing applications. Graphical abstract fx1 Highlights • Tight UF membrane is used in efficient dye purification for digital printing. • Tight UF membrane has consistently high rejection (> 98.12%) for 7 reactive dyes. • Integrated UF-diafiltration process removes 99.88% of Na 2 SO 4 with ~9 diavolumes. • Reactive blue 19 is concentrated to 142.60 g L−1 with 99.83% purity in diafiltration. • Complete flux recovery for UF membrane is obtained after NaOH/HCl cleaning. [ABSTRACT FROM AUTHOR]

Membrane wetting and fouling substantially limits application and deployment of membrane distillation process. Designing high-performance superhydrophobic membranes offers an effective solution to solve the challenge. In this work, a highly durable superhydrophobic surface (water contact angle of 170.8 ± 1.3°) was constructed via a facile and rapid spray-coating of extremely hydrophobic SiO 2 nanoparticles onto a porous polyvinylidene fluoride (PVDF) substrate for membrane distillation. The superhydrophobic membrane coated by fluorinated SiO 2 nanoparticles exhibited a superior physicochemical stability in a wide range of extreme environments (i.e., NaOH, HCl, hot water, rust water, humic acid solution, ultrasonication, and high-speed water scouring). During 8-h continuous membrane distillation desalination experiment, the coated superhydrophobic membrane experienced a consistently stable water vapor flux (ca. 19.1 kg·m−2·h−1) and desalination efficiency (99.99 %). Additionally, such a stable superhydrophobicity endowed the spray-coated PVDF membrane to overcome membrane wetting and fouling during membrane distillation of highly saline solutions containing foulants (i.e., humic acid and rust). Results reported in this study provides a useful concept and strategy in facile construction of robust superhydrophobic membranes via spray-coating for effective membrane distillation. [Display omitted] • Spray-coating of hydrophobic SiO 2 was used to fabricate superhydrophobic membranes. • Superhydrophobic membrane experienced strong physicochemical stability in harsh environment. • Superhydrophobic membrane had a superior desalination efficacy in membrane distillation. • Superhydrophobic membrane had excellent antifouling properties during membrane distillation. [ABSTRACT FROM AUTHOR]

The effect of competing ions in wastewater on the phosphate pre-concentrating efficiency by selectrodialysis was demonstrated in this study. Nitrate, bicarbonate and sulphate are three ions frequently present in wastewater. An inhibition of these ions to the phosphate concentrating efficiency was found to occur initially, but if the system runs for a longer time, the effect disappears. In the presence of nitrate, bicarbonate and sulphate, the phosphate concentrating efficiency in the product was significantly reduced from 188% to 78% after 210 min, but this could be recovered to 161% after 300 min. In addition, when operating selectrodialysis with synthetic municipal wastewater, phosphate was concentrated in the product with a twofold concentration compared to the initial concentration in the wastewater. Scaling on the cation exchange membrane and monovalent selective anion exchange membranes was observed during the selectrodialysis process when carrying out the experiment with synthetic municipal wastewater, but the membranes were almost completely recovered after a simple acid cleaning with 0.1 M HCl solution for 1 h. The present study indicates that selectrodialysis successfully concentrates phosphate from wastewater in the product stream, which makes a subsequent crystallization process viable to recover phosphate from wastewater. [ABSTRACT FROM AUTHOR]

Abstract: A promising and sustainable renewable source of phosphate was obtained through crystallization of calcium phosphate from wastewater. The aim of the present study was to evaluate the feasibility of an integrated selectrodialysis/crystallization process to recover phosphate, in which selectrodialysis was first used to pre-concentrate the phosphate before crystallization in a pellet reactor. The results of selectrodialysis show that an increase in current density, initial pH of the product, and initial feed concentration of phosphate led to an increase in phosphate concentration in the product. The desalination efficiency from wastewater was 87%, the phosphate concentration in the product can reach 16 mM with a purity of 44%, the current efficiency to transport phosphate and chloride was 26.6% for standard anion exchange membrane and 63% for monovalent selective anion exchange membrane. The optimal operational conditions for phosphate recovery with a pellet reactor were examined by changing the initial concentration, the pH and the superficial velocity. A precipitation efficiency of 82.7% of phosphate was achieved at pH 11, an inlet concentration of phosphates of 2.5 mM, a Ca/P molar ratio of 1.5 and a superficial velocity of 61 m/h. From the results, it can be concluded that the pellet reactor combined with selectrodialysis is an appropriate method to recover phosphate from wastewater as calcium phosphate, which is not only technically but also environmentally feasible, reducing water pollution, preventing eutrophication and yielding valuable and sustainable resources. [Copyright &y& Elsevier]

Highlights: [•] A zero discharge process was proposed to recover acid, base and glyphosate. [•] The recovery of glyphosate was over 96%, which is acceptable for industrial scale. [•] η for producing NaOH with 2.0molL−1 is 67% and E is 2.97kWhkg−1. [Copyright &y& Elsevier]

Effective extraction of useful resources from high-salinity textile wastewater is a critical pathway for sustainable wastewater management. In this study, an integrated loose nanofiltration-electrodialysis process was explored for simultaneous recovery of dyes, NaCl and pure water from high-salinity textile wastewater, thus closing the material loop and minimizing waste emission. Specifically, a loose nanofiltration membrane (molecular weight cutoff of ~800 Da) was proposed to fractionate the dye and NaCl in the high-salinity textile wastewater. Through a nanofiltration-diafiltration unit, including a pre-concentration stage and a constant-volume diafiltration stage, the dye could be recovered from the high-salinity textile wastewater, being enriched at a factor of ~9.0, i.e., from 2.01 to 17.9 g·L−1 with 98.4% purity. Assisted with the subsequent implementation of electrodialysis, the NaCl concentrate and pure water were effectively reclaimed from the salt-containing permeate coming from the loose nanofiltration-diafiltration. Simultaneously, the produced pure water was further recycled to the nanofiltration-diafiltration unit. This study shows the potential of the integration of loose nanofiltation-diafiltration with electrodialysis for sufficient resource extraction from high-salinity textile wastewater. [Display omitted] • Integration of loose nanofiltration (NF) with electrodialysis is proposed for textile wastewater treatment. • Loose NF-diafiltration enriches the dye from 2.01 to 17.9 g·L−1 with a purity of 98.4%. • 99.94% of salt is removed by loose NF-diafiltration with 7 diavolumes. • Subsequent electrodialysis effectively recovers water and salt from NF-diafiltration permeate. • No significant fouling of ion exchange membranes is observed in electrodialysis performance. [ABSTRACT FROM AUTHOR]

• Metal-organic coordination complex coating effectively tailors surface property of nanofiltration membrane. • The nanofiltration membrane yields a molecular weight cutoff of 297 Da after 15-s coating. • The coated nanofiltration membrane shows impressive fractionation of humic substances and salts. • Nanofiltration-diafiltration can enrich and purify humic substances from landfill leachate concentrate. Sustainable treatment of the highly saline landfill leachate concentrate for application as green fertilizer calls for effective fractionation of the existing humic substances and inorganic salts; advanced selective nanofiltration membranes are proposed for this. One-step, rapid assembly of a tannic acid-Fe3+ coordination complex is a promising strategy to endow the membranes with an enhanced nanofiltration performance. In this study, a robust and homogeneous tannic acid-Fe3+ coordination complex layer was effectively coated onto the surface of a loose nanofiltration substrate in an extremely short time (15 s). After the coating of the tannic acid-Fe3+ coordination complex layer, the nanofiltration membrane showed a significantly reduced molecule weight cutoff (i.e., reduction from 601 to 279 Da) and thus enhanced selectivity towards humic substances. Specifically, the rejection to humic substances of the coated nanofiltration membrane increased from 95.31±0.54% to 99.32±0.18% with negligible rise in salt rejection, demonstrating an enhanced fractionation efficacy for humic substances and salts. Assisted by a diafiltration operation with the coated nanofiltration membrane, humic substances in the landfill leachate concentrate were effectively purified and extracted with 96.60% recovery. Particularly, the humic substances were linearly enriched by ca. 7.8 folds (i.e., from 1837 to 13970 mg·L−1) with a purity of 98.91% for potential application as liquid fertilizer. The one-step rapid tannic acid-Fe3+ coordination complex coating exhibits an impressive efficacy to engineer advanced nanofiltration membranes that could be applied at a large scale for sustainable resource extraction from landfill leachate concentrate. [Display omitted] [ABSTRACT FROM AUTHOR]

Designing a stable and uniform hydrophilic material for separation of oil and water is strongly desired for sustainable management of oily wastewater. Herein, a stable and uniform bio-inspired coating onto the non-woven fabric substrate with superhydrophilicity and underwater superoleophobicity via rapid co-deposition of dopamine and polyethylenimine was demonstrated. Ammonium persulfate outperformed other oxidants (e.g., Cu2+-H 2 O 2 and NaIO 4) to rapidly trigger the co-deposition of dopamine and polyethylenimine for homogeneous superhydrophilic and underwater superoleophobic surface engineering. Furthermore, the co-deposition conditions, i.e., concentration of ammonium persulfate and exposure duration, have a positive dependence on the hydrophilicity and underwater oleophobicity of the coated fabric membranes. Specifically, the superhydrophilicity and underwater superoleophobicity (underwater oil contact angle of 165.4 ± 1.1°, sliding angle of 2.5 ± 0.5°) can be obtained for the coated fabric membranes at the optimal co-deposition condition (i.e., 28.5 mmol L−1 persulfate and coating duration of 7 h), showing a great potential in gravitational oil-water separation (permeation flux >115,000 L m−2 h−1; oil rejection >99.2%). Integrating with a superhydrophobic copper mesh, the oil-water mixed solution can be continuously and sufficiently separated, realizing simultaneous recovery of pure oil and water from oily wastewater. In addition, the bio-inspired coating displays a strong long-term chemical robustness and stability in extreme environments (i.e., acidic/alkaline solutions and oils). The study provides a facile, cost-effective and practical strategy in constructing superhydrophilic and underwater superoleophobic interfaces for sustainable treatment of oily wastewater. Image 1 • Mussel-inspired coating endows non-woven fabric membranes with robust superhydrophilic interface. • Persulfate have an impressive efficacy to rapidly trigger the mussel-inspired coating. • The mussel-inspired coating yields an underwater oil contact angle of 165.4 ± 1.1°. • The superhydrophilic fabric membrane has a permeation flux of >115000 L m−2 h−1 with >99.2% oil rejection. • Integrating bio-inspired fabric membrane with superhydrophobic copper mesh can continuously recover oil and water. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N 2 O) emission is an environmental problem related to composting. Recently, the electric field-assisted aerobic composting process has been found to be effective for enhancing compost maturity and mitigating N 2 O emission. However, the insertion of electrodes into the compost pile causes electrode erosion and inconvenience in practical operation. In this study, a novel alternating magnetic field-assisted aerobic composting (AMFAC) process was tested by applying an alternating magnetic field (AMF) to a conventional aerobic composting (CAC) process. The total N 2 O emission of the AMFAC process was reduced by 39.8% as compared with that of the CAC process. Furthermore, the results demonstrate that the AMF weakened the expressions of the amo A, nar G, and nir S functional genes (the maximum reductions were 96%, 83.7%, and 95.5%, respectively), whereas it enhanced the expression of the nos Z functional gene by a maximum factor of 36.5 as compared with that in CAC. A correlation analysis revealed that the nitrification and denitrification processes for N 2 O emission were suppressed in AMFAC, the main source of N 2 O emission of which was denitrification. The findings imply that AMFAC is an effective strategy for the reduction of N 2 O emission during aerobic composting. ga1 Alternating magnetic field-assisted aerobic composting. • A novel alternating magnetic field-assisted aerobic composting process has been developed. • The alternating magnetic field significantly mitigated the N 2 O emission effect. • The alternating magnetic field inhibited the expressions of the amo A, nar G, and nir S functional genes. • The alternating magnetic field promoted nos Z expression. [ABSTRACT FROM AUTHOR]

• Superhydrophobic PVDF membrane was fabricated by spray-coating of fluorinated SiO 2 NPs. • Superhydrophobic PVDF membrane had a water contact angle of 171.8 ± 1.1° and sliding angle of 1.69 ± 0.13°. • The modified PVDF membrane maintained stable superhydrophobicity under harsh conditions. • The prepared membrane has consistent separation efficiencies up to 99.88 ± 0.03% in water-in-oil emulsions over 40 cycles. • Scale-up fabrication of superhydrophobic PVDF membrane was successfully performed. Hydrophobic anti-wetting membranes have many applications, such as oily wastewater treatment via oil/water separation, desalination via membrane distillation, and carbon capture via gas-liquid membrane contactors. Herein, we used a simple and scalable method to fabricate robust superhydrophobic polyvinylidene fluoride (PVDF) based membranes by one-step spray-coating of fluorinated SiO 2 nanoparticles. The prepared PVDF membrane was systematically characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and contact angle measurements. The modified PVDF membrane had excellent superhydrophobicity with an extremely high water contact angle up to 171.8 ± 1.1° and a low sliding angle of 1.69 ± 0.13°, due to the fluorinated close-packed hydrophobic SiO 2 nanoparticles on the surface. The modified PVDF membrane maintained its relatively stable superhydrophobicity under various harsh conditions, i.e., exposure in hot water, NaOH and HCl, ultrasonication and high-speed flushing, indicating the superior robustness and stability. The prepared membrane also exhibited consistent separation efficiencies up to 99.88 ± 0.03% in water-in-oil emulsions, and superior recyclability and durability over 40 cycles. In addition, spray-coating showed its great promise in engineering various superhydrophobic surfaces on different substrates and excellent scalability in fabricating large-size membranes. This study demonstrates a facilely scalable spray-coating method for engineering robust superhydrophobic surfaces and membranes that can be potentially used for various gas, vapor and water/oil separations. [ABSTRACT FROM AUTHOR]