Enhanced Desulfurization Performance of ZIF-8/PEG MMMs: Effect of ZIF-8 Particle Size.

Constructing efficient and continuous transport pathways in membranes is a promising and challenging way to achieve the desired performance in the pervaporation process. The incorporation of various metal-organic frameworks (MOFs) into polymer membranes provided selective and fast transport channels and enhanced the separation performance of polymeric membranes. Particle size and surface properties are strongly related to the random distribution and possible agglomeration of MOFs particles, which may lead to poor connectivity between adjacent MOFs-based nanoparticles and result in low-efficiency molecular transport in the membrane.

GO-Based Membranes for Desalination.

Graphene oxide (GO), owing to its atomic thickness and tunable physicochemical properties, exhibits fascinating properties in membrane separation fields, especially in water treatment applications (due to unimpeded permeation of water through graphene-based membranes). Particularly, GO-based membranes used for desalination via pervaporation or nanofiltration have been widely investigated with respect to membrane design and preparation. However, the precise construction of transport pathways, facile fabrication of large-area GO-based membranes (GOMs), and robust stability in desalination applications are the main challenges restricting the industrial application of GOMs.

Electron structure modulation and bicarbonate surrounding enhance Fenton-like reactions performance of Co-Co PBA.

Although several strategies have been developed to improve the efficiency of heterogeneous Fenton-like reactions, investigating the relationship among the electronic properties of the catalyst surface, the complex water matrix and catalytic activity remains challenges. Herein, the electron density of the active site Co(II) in Co Prussian blue analogs (Co-PBAs) is proved to be modulated by the anion source method. The elevated electron density of Co(II) and the higher metallicity of the catalyst lead to an increase in electron transport efficiency as revealed by X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FT-IR), and density functional theory (DFT) calculations.

Preparation of lignosulfonate-based nanofiltration membranes with improved water desalination performance.

Pulping and papermaking generate large amounts of waste in the form of lignosulfonates which have limited valorized applications so far. Herein, we report a novel lignosulfonate-based nanofiltration membrane, prepared by using polyethylenimine (PEI) and sodium lignosulfonate (SL) via a layer-by-layer (LbL) self-assembly. As a low-cost and renewable natural polyelectrolyte, SL is selected to replace the synthetic polyelectrolyte commonly used in the conventional LbL fabrication for composite membranes.

Humic Acid Removal from Water with PAC-Al: Effect of Calcium and Kaolin and the Action Mechanisms.

Polyaluminum chloride with a dominant species of Al (PAC-Al) was prepared in laboratory and used for humic acid (HA) removal from water. The action properties and mechanisms of PAC-Al, HA, calcium, and kaolin were tested and discussed. The results showed that the existence of calcium or kaolin contributed to the HA removal when the PAC-Al dosage was deficient and had no obvious effect when the amount of PAC-Al was sufficient.

Poly(vinyl alcohol)-Modified Membranes by TiCT for Ethanol Dehydration via Pervaporation.

In this paper, PVA/TiCT mixed matrix membranes (MMMs) were prepared by mixing the synthesized TiCT with the PVA matrix, and the pervaporation (PV) performance of the ethanol-water binary system was tested. The morphology, structural properties, and surface characteristics of the membranes were investigated by scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, degree of swelling, and water contact angle. The PVA/TiCT MMMs exhibit excellent compatibility and swelling resistance.

High-poly-aluminum chloride sulfate coagulants and their coagulation performances for removal of humic acid.

High-poly-aluminum chloride sulfate (HPACS) coagulants with different [SO ]/[Al] molar ratio () were prepared and proved to have high coagulation efficiency for the removal of humic acid and strong stability for storage and application. The results showed that the higher the SO addition, the bigger the aluminum polymerization particles and the more the polymerization Al existed in the prepared HPACS coagulants. The HPACS exhibited higher coagulation efficiency, a better aging stability and stronger resistance to the change of pH and Ca concentration of raw water than the polyaluminum chloride (PAC) and poly-aluminum chloride sulfate (PACS) reported before.

Improved Desulfurization Performance of Polyethyleneglycol Membrane by Incorporating Metal Organic Framework CuBTC.

In this paper, copper benzene-1,3,5-tricarboxylate (CuBTC) was incorporated into polyethylenglyol (PEG) to prepare a mixed matrix membrane (MMM) for pervaporation desulfurization. The characterization results showed that the prepared CuBTC particles had an ideal octahedral shape and micropores. The Cu in CuBTC interacts with thiophene via π-complexation, thus enhancing the separation performance of the hybrid membranes.

Exploiting Giant-Pore Systems of Nanosized MIL-101 in PDMS Matrix for Facilitated Reverse-Selective Hydrocarbon Transport.

Membrane gas separation offers high energy efficiency, easy operation, and reduced environmental impacts for vast hydrocarbon recovery in the petrochemical industry. However, the recovery of real light hydrocarbon mixtures (e.g.

Preparation of graphene oxide/poly(vinyl alcohol) composite membrane and pervaporation performance for ethanol dehydration.

Although poly(vinyl alcohol) (PVA) membranes are widely used in solvent dehydration by pervaporation, the separation factor is rather limited. Considering this, novel PVA mixed matrix membranes with graphene oxide (GO) nanosheets were prepared. poly(acrylonitrile) ultrafiltration (PAN) membrane was used as support layer.

Preparation of SGO-modified nanofiltration membrane and its application in SO and Cl separation in salt treatment.

The lack of fresh water in the world makes the search for an effective method to decontaminate water an urgent priority. An important step is to remove different multivalent ions in salt treatment. Nanofiltration (NF) has been used for treating water containing different kinds of salts.

Performance of a pervaporation system for the separation of an ethanol-water mixture using fractional condensation.

Polydimethylsiloxane (PDMS)/polyvinylidene fluoride (PVDF) composite membranes were fabricated and subsequently applied in ethanol recovery from an ethanol-water mixture by pervaporation (PV) using fractional condensation. The effects of feed temperature and feed flow velocity on the pervaporative properties of PDMS/PVDF composite membranes were investigated. Scanning electron microscopy (SEM) results showed that PDMS was coated uniformly on the surface of porous PVDF substrate, and the PDMS separation layer was dense with a thickness of 1.

Drinking water treatment using a submerged internal-circulation membrane coagulation reactor coupled with permanganate oxidation.

A submerged internal circulating membrane coagulation reactor (MCR) was used to treat surface water to produce drinking water. Polyaluminum chloride (PACl) was used as coagulant, and a hydrophilic polyvinylidene fluoride (PVDF) submerged hollow fiber microfiltration membrane was employed. The influences of trans-membrane pressure (TMP), zeta potential (ZP) of the suspended particles in raw water, and KMnO dosing on water flux and the removal of turbidity and organic matter were systematically investigated.

Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties.

In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM), contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies.

Layer-by-Layer Fabrication of High-Performance Polyamide/ZIF-8 Nanocomposite Membrane for Nanofiltration Applications.

The conventional blending fabrication for thin-film nanocomposite (TFN) membranes is to disperse porous fillers in aqueous/organic phases prior to interfacial polymerization, and the aggregation of fillers may lead to the significant decrease in membrane performance. To overcome this limitation, we proposed a novel layer-by-layer (LBL) fabrication to prepare a polyamide (PA)/ZIF-8 nanocomposite membrane with a multilayer structure: a porous substrate, a ZIF-8 interlayer, and a PA coating layer. The PA/ZIF-8 (LBL) membrane for nanofiltration applications was prepared by growing an interlayer of ZIF-8 nanoparticles on an ultrafiltration membrane through in situ growth and then coating it with an ultrathin PA layer through interfacial polymerization.

Coagulation pretreatment of highly concentrated acrylonitrile wastewater from petrochemical plants.

Acrylonitrile (AN) wastewater is a heavily polluted and a likely hazardous liquid that is generated during the production of AN. Several chemical methods for the pretreatment of AN wastewater are available in laboratory scale. However, the harsh reaction conditions and high operational cost make these methods undesirable.

Preparation of poly(phthalazinone-ether-sulfone) sponge-like ultrafiltration membrane.

Poly(phthalazinone-ether-sulfone) (PPES) polymer is a relatively newly developed material with a bis(4-fluorodiphenyl) sulfone group. The formation of the PPES membrane by wet-phase inversion can proceed according to a slow or fast gelation method. These formation mechanisms were studied experimentally.

Enhanced pervaporation performance of multi-layer PDMS/PVDF composite membrane for ethanol recovery from aqueous solution.

Multi-layer PDMS/PVDF composite membrane with an alternative PDMS/PVDF/non-woven-fiber/PVDF/PDMS configuration was prepared in this paper. The porous PVDF substrate was obtained by casting PVDF solution on both sides of non-woven fiber with immersion precipitation phase inversion method. Polydimethylsiloxane (PDMS) was then cured by phenyltrimethoxylsilane (PTMOS) and coated onto the surface of porous PVDF substrate one layer by the other to obtain multi-layer PDMS/PVDF composite membrane.

Pervaporation separation of thiophene-heptane mixtures with polydimethylsiloxane (PDMS) membrane for desulfurization.

Cross-linked polydimethylsiloxane (PDMS)-polyetherimide (PEI) composite membranes were prepared, in which asymmetric microporous PEI membrane prepared with phase inversion method was acted as the microporous supporting layer in the flat-plate composite membrane. Membrane characterization was conducted by Fourier transform infrared and scanning electronic microscopy analysis. The composite membranes were employed in pervaporation separation of n-heptane-thiophene mixtures.

[Measurement of diffusion coefficients of polar solvent and nonpolar solvent at infinite dilution in polyethylene].

Gas chromatography is a new, fast, accurate and convenient technique to study the correlation of small molecule solvents and polymer membrane materials. It can measure many parameters of dissolution and diffusing characters of a small molecule in a polymer. The retention times and the peak widths at half-height of five small molecule solvents (n-hexane, n-heptane, n-decane, ethanol and water) in the stationary phase of polyethylene were measured.