Practical Considerations in the Design and Use of Non-Crystalline Metal-Organic Frameworks.

The concept of non-Crystalline Metal-Organic Frameworks (MOFs) is both theoretically exciting and rich in potential applications. Since their conceptual introduction, research in this field has experienced significant growth. This review provides a comprehensive overview of the design, synthesis, and applications of non-crystalline MOFs, highlighting the current state of the art.

Engineering Superhydrophilic and Fouling-Free COF Armor for Ultrafast Oil-Water Separation.

Polymeric nanofibrous membranes are promising candidates for highly efficient oily wastewater separation, however, they suffer from irreversible membrane fouling. Herein, hydrophilic β-ketoenamine-linked covalent organic frameworks (COFs)-modified polyacrylonitrile (PAN) nanofibrous membranes (PNMs-COF) are developed, and the microstructures and hydrophilicities of the membranes are finely tailored. The hydrophilic rigid COF armor can induce the formation of hydrogen bonds with water, increase the polar component of the apparent surface tension, enhancing the driving force toward water and increasing the repulsion against oil droplets.

Elucidating the role of carbon dioxide (CO) in the transformation of hydrogen cyanide (HCN) during the regeneration of spent fluid catalytic cracking (FCC) catalysts.

The emission of hydrogen cyanide (HCN) from the industrial fluid catalytic cracking (FCC) catalyst regenerator is a concerning pollutant that is highly toxic. Yet, the underpinning rationale particularly the role of carbon dioxide (CO) and its competition with O, remains poorly understood. Through the tests of three industrial spent FCC catalysts via temperature-programmed oxidation and Chemkin simulation, this study revealed a dual role of CO in the transformation of HCN.

Assessing the Performance of Different Treatment Methods in Removing Tetracycline from Wastewater: Efficiency and Cost Evaluation.

To tackle the pollution of tetracycline (TC) in aqueous environments, a few treatment methods, including ozonation, adsorption, and photocatalytic degradation, were compared using a novel and sustainable granular activated carbon-based zinc oxide nanoparticle (ZnO@GAC) composite. The results demonstrate that the ZnO@GAC composite towards TC exhibited a high removal efficiency of 82.1% in a batch adsorption system.

In-Situ Hydrothermal Fabrication of ZnO-Loaded GAC Nanocomposite for Efficient Rhodamine B Dye Removal via Synergistic Photocatalytic and Adsorptive Performance.

In this work, zinc oxide (ZnO)/granular activated carbon (GAC) composites at different ZnO concentrations (0.25M-ZnO@GAC, 0.5M-ZnO@GAC, and 0.

Fabrication of Loose Nanofiltration Membrane by Crosslinking TEMPO-Oxidized Cellulose Nanofibers for Effective Dye/Salt Separation.

Dye/salt separation has gained increasing attention in recent years, prompting the quest to find cost-effective and environmentally friendly raw materials for synthesizing high performance nanofiltration (NF) membrane for effective dye/salt separation. Herein, a high-performance loose-structured NF membrane was fabricated via a simple vacuum filtration method using a green nanomaterial, 2,2,6,6-tetramethylpiperidine-1-oxide radical (TEMPO)-oxidized cellulose nanofiber (TOCNF), by sequentially filtrating larger-sized and finer-sized TOCNFs on a microporous substrate, followed by crosslinking with trimesoyl chloride. The resulting TCM membrane possessed a separating layer composed entirely of pure TOCNF, eliminating the need for other polymer or nanomaterial additives.

Accurate prediction of solvent flux in sub-1-nm slit-pore nanosheet membranes.

Nanosheet-based membranes have shown enormous potential for energy-efficient molecular transport and separation applications, but designing these membranes for specific separations remains a great challenge due to the lack of good understanding of fluid transport mechanisms in complex nanochannels. We synthesized reduced MXene/graphene hetero-channel membranes with sub-1-nm pores for experimental measurements and theoretical modeling of their structures and fluid transport rates. Our experiments showed that upon complete rejection of salt and organic dyes, these membranes with subnanometer channels exhibit remarkably high solvent fluxes, and their solvent transport behavior is very different from their homo-structured counterparts.

Nanoconfinement enabled non-covalently decorated MXene membranes for ion-sieving.

Covalent modification is commonly used to tune the channel size and functionality of 2D membranes. However, common synthesis strategies used to produce such modifications are known to disrupt the structure of the membranes. Herein, we report less intrusive yet equally effective non-covalent modifications on TiCT MXene membranes by a solvent treatment, where the channels are robustly decorated by protic solvents via hydrogen bond network.

Construction of 2D/0D Graphene Oxide/Copper(I) Oxide-Incorporated Titanium Dioxide Mixed-Dimensional Membranes with Ultrafast Water Transport and Enhanced Antifouling Properties.

Graphene oxide (GO) membranes are emerging for water treatment. Meanwhile, challenges remain due to membrane fouling and their instability in aqueous solutions. Herein, a novel GO-based mixed-dimensional membrane with superior antifouling and nonswelling properties was prepared by assembling two-dimensional (2D) GO nanosheets and zero-dimensional (0D) copper(I) oxide-incorporated titanium dioxide photocatalyst (CT).

Pyro-layered heterostructured nanosheet membrane for hydrogen separation.

Engineering different two-dimensional materials into heterostructured membranes with unique physiochemical properties and molecular sieving channels offers an effective way to design membranes for fast and selective gas molecule transport. Here we develop a simple and versatile pyro-layering approach to fabricate heterostructured membranes from boron nitride nanosheets as the main scaffold and graphene nanosheets derived from a chitosan precursor as the filler. The rearrangement of the graphene nanosheets adjoining the boron nitride nanosheets during the pyro-layering treatment forms precise in-plane slit-like nanochannels and a plane-to-plane spacing of ~3.

Smart utilisation of reverse solute diffusion in forward osmosis for water treatment: A mini review.

Forward osmosis (FO) has been widely studied as a promising technology in wastewater treatment, but undesirable reverse solute diffusion (RSD) is inevitable in the FO process. The RSD is generally regarded as a negative factor for the FO process, resulting in the loss of draw solutes and reduced FO efficiency. Conventional strategies to address RSD focus on reducing the amount of reverse draw solutes by fabricating high selective FO membranes and/or selecting the draw solute with low diffusion.

Understanding the membrane fouling control process at molecular level in the heated persulfate activation- membrane distillation hybrid system.

Sulfate radical (SO) based advanced oxidation is considered as a promising pretreatment strategy to degrade organic pollutants and thereby mitigate the membrane fouling in the membrane process. In this study, heat-activated persulfate (PS) activation was integrated with the membrane distillation (MD) process for the alleviation of membrane fouling in treatment of wastewater treatment plant (WWTP) secondary effluent and surface water. In-depth understanding of the molecular fate during membrane fouling control process was performed by using a non-targeted screening method of two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF-MS) coupling with multiple characterizations.

Construction of PPSU-MoS/PA-MIL-101(Cr) Membrane with Highly Enhanced Permeance and Stability for Organic Solvent Nanofiltration.

Membranes with excellent separation performance and stability are needed for organic solvent nanofiltration in industrial separation and purification processes. Here we reported a newly PPSU-MoS/PA-MIL-101(Cr) composite membrane with high permeance, good selectivity and stability. The MIL-101(Cr) was introduced in the polyamide (PA) layer via the PIP/TMC interfacial polymerization process on a microporous PPSU-MoS substrate.

Promotion effect of Ni doping on the oxygen resistance property of Fe/CeO catalyst for CO-SCR reaction: Activity test and mechanism investigation.

Catalytic reduction of NO using CO, which is usually present in the flue gas of the iron and steel industry, is considered as an economical and eco-friendly de-NO method (CO-SCR). However, the oxygen present in the flue gas will significantly inhibit the CO-SCR activity of the catalyst, thereby limiting its industrial application. Herein, catalysts based on iron and cerium oxides were prepared and modified with different metals to investigate their performance for the CO-SCR reaction in the presence of oxygen.

Remediation of poly-and perfluoroalkyl substances (PFAS) contaminated soil using gas fractionation enhanced technology.

This study investigated a gas fractionation enhanced soil washing method for poly-and perfluoroalkyl substances (PFAS) removal from contaminated soil. With the assistance of gas fractionation, PFAS removal was increased by a factor of 9, compared to the conventional soil washing method. Pre-extraction (pre-treatment) of the soil with water before gas fractionation enhanced PFAS removal from soil.

The role of lateral size of MXene nanosheets in membrane filtration of dyeing wastewater: Membrane characteristic and performance.

New two-dimensional (2D) material MXene based lamellar membranes constructed from 2D MXene nanosheets have shown promising potential for water treatment with excellent selective property and high water flux. However, the effect of lateral size of MXene nanosheets on the membrane property and performance was rarely considered. Herein, the MXene nanosheets with different lateral size (552.

Recent Advances in Catalysts and Membranes for MCH Dehydrogenation: A Mini Review.

Methylcyclohexane (MCH), one of the liquid organic hydrogen carriers (LOHCs), offers a convenient way to store, transport, and supply hydrogen. Some features of MCH such as its liquid state at ambient temperature and pressure, large hydrogen storage capacity, its well-known catalytic endothermic dehydrogenation reaction and ease at which its dehydrogenated counterpart (toluene) can be hydrogenated back to MCH and make it one of the serious contenders for the development of hydrogen storage and transportation system of the future. In addition to advances on catalysts for MCH dehydrogenation and inorganic membrane for selective and efficient separation of hydrogen, there are increasing research interests on catalytic membrane reactors (CMR) that combine a catalyst and hydrogen separation membrane together in a compact system for improved efficiency because of the shift of the equilibrium dehydrogenation reaction forwarded by the continuous removal of hydrogen from the reaction mixture.

Study of MOF incorporated dual layer membrane with enhanced removal of ammonia and per-/poly-fluoroalkyl substances (PFAS) in landfill leachate treatment.

Landfill leachate is a highly polluted and complex wastewater as it contains large amounts of organic matters, ammonia‑nitrogen, heavy metals, and per-/poly-fluoroalkyl substances (PFAS), which makes its treatment very challenging. In this paper, hydrophilic/hydrophobic dual layer membranes combining advantages of pervaporation and membrane distillation was employed to treat leachate in a direct contact membrane distillation (DCMD) configuration. An aluminum fumarate (AlFu) metal organic framework (MOF) incorporated poly(vinyl alcohol) (PVA) hydrophilic layer was coated on hydrophobic PTFE membrane to overcome the low separation efficiency of PFAS and ammonia and wetting issues encountered by the conventional hydrophobic PTFE membrane used for DCMD.

Dual Functions of a Au@AgNP-Incorporated Nanocomposite Desalination Membrane with an Enhanced Antifouling Property and Fouling Detection Via Surface-Enhanced Raman Spectroscopy.

Membrane fouling has remained a major challenge limiting the wide application of membrane technology because it reduces the efficiency and shortens the lifespan of the membrane, thus increasing the operation cost. Herein we report a novel dual-function nanocomposite membrane incorporating silver-coated gold nanoparticles (Au@AgNPs) into a sulfosuccinic acid (SSA) cross-linked poly(vinyl alcohol) (PVA) membrane for a pervaporation desalination. Compared with the control PVA membrane and PVA/SSA membrane, the Au@AgNPs/PVA/SSA membrane demonstrated a higher water flux and better salt rejection as well as an enhanced antifouling property.

Facile construction of dual heterojunction CoO@TiO/MXene hybrid with efficient and stable catalytic activity for phenol degradation with peroxymonosulfate under visible light irradiation.

Photocatalysis and peroxymonosulfate (PMS) based advanced oxidation processes (AOP) are emerging technology for the degradation of refractory organic pollutant in the field of water treatment. Here we report a novel CoO@TiO/MXene (CTM) hybrid through a facile sonication-hydrothermal method for efficient degradation of phenol via an integrated PMS activation-photocatalysis process. Benefiting from the proper position and superior suitability of the band structure, a dual interfacial charge transport channel was constructed, boosting the separation of photo-generated charge carriers and generating sufficient potential difference for redox reaction.

Evolution mechanism of transition metal in NH-SCR reaction over Mn-based bimetallic oxide catalysts: Structure-activity relationships.

The unexpected phenomenon in which different transition metals (Co, Ni and Cu) presented significant variation of participation levels as the auxiliaries in Mn-based bimetallic oxide catalysts were reported here. It is found that the Co element more easily to form Mn enriched surface bimetallic oxides with Mn than Ni and Cu, resulting in Co-MnO exhibited the best deNO activity and SO tolerance, followed by Ni-MnO and Cu-MnO. The role of different transition metal and structure-activity relationships were systematically investigated by advanced techniques including Synchrotron XAFS and in situ DRIFTs analysis.

State-of-the-Art and Opportunities for Forward Osmosis in Sewage Concentration and Wastewater Treatment.

The application of membrane technologies for wastewater treatment to recover water and nutrients from different types of wastewater can be an effective strategy to mitigate the water shortage and provide resource recovery for sustainable development of industrialisation and urbanisation. Forward osmosis (FO), driven by the osmotic pressure difference between solutions divided by a semi-permeable membrane, has been recognised as a potential energy-efficient filtration process with a low tendency for fouling and a strong ability to filtrate highly polluted wastewater. The application of FO for wastewater treatment has received significant attention in research and attracted technological effort in recent years.

Review of Transport Phenomena and Popular Modelling Approaches in Membrane Distillation.

In this paper, the transport phenomena in four common membrane distillation (MD) configurations and three popular modelling approaches are introduced. The mechanism of heat transfer on the feed side of all configurations are the same but are distinctive from each other from the membrane interface to the bulk permeate in each configuration. Based on the features of MD configurations, the mechanisms of mass and heat transfers for four configurations are reviewed together from the bulk feed to the membrane interface on the permeate but reviewed separately from the interface to the bulk permeate.

Combination of bacitracin-based flocculant and surface enhanced Raman scattering labels for flocculation, identification and sterilization of multiple bacteria in water treatment.

Bacteria, especially antibiotic-resistant bacteria, in water threaten public health in countries. Simultaneous flocculation, sterilization and identification of bacteria are great challenge in water treatment. Herein we presented a three-in-one compound through combining a novel Bacitracin-based flocculant (B-g-PAMDAC) and surface enhanced Raman scattering (SERS) labels, the modified Au@AgNPs using graphene oxide (GO) and 4-mercaptophenylboronic acid (4-MPBA).

Functionalized Carbon Nanotube-Mediated Transport in Membranes Containing Fixed-Site Carriers for Fast Pervaporation Desalination.

Facilitated transport membranes (FTMs) comprising fixed carrier agents hold considerable potential for obtaining selective and fast separation of mixed molecules in either gas or liquid state. However, diffusion through the membrane is inevitably affected by the resistance from the polymer matrix, where the carrier is absent. Herein, a poly(vinyl alcohol) (PVA)-based separating layer combining the merits of fixed-site transport agents and inorganic nanofillers was developed to reduce the transport resistance.