Mitigated membrane fouling and enhanced removal of extracellular antibiotic resistance genes from wastewater effluent via an integrated pre-coagulation and microfiltration process.

Antibiotic resistance genes (ARGs) have been regarded as an emerging pollutant in municipal wastewater treatment plant (WWTP) effluents due to their potential risk to human health and ecological safety when reused for landscape and irrigation. Conventional wastewater treatment processes generally fail to effectively reduce ARGs, especially extracellular ARGs (eARGs), which are persistent in the environment and play an important role in horizontal gene transfer via transformation. Herein, an integrated process of pre-coagulation and microfiltration was developed for removal of ARGs, especially eARGs, from wastewater effluent.

Synergistic Effect and Characterization of Graphene/Carbon Nanotubes/Polyvinyl Alcohol/Sodium Alginate Nanofibrous Membranes Formed Using Continuous Needleless Dynamic Linear Electrospinning.

In this study, a self-made continuous needleless dynamic linear electrospinning technique is employed to fabricate large-scale graphene (Gr)/carbon nanotubes (CNT)/polyvinyl alcohol (PVA)/sodium alginate (SA) nanofibrous membranes. The synergistic effect of Gr and CNT fillers in the PVA/SA membrane is explored in depth by changing the volume ratio (/) of Gr and CNT as 10:0, 8:2, 6:4, 4:6, 2:8, and 0:10. Microstructure, functional group, conductivity, and hydrophilicity of PVA/SA/Gr/CNT membranes was characterized.

Simultaneous oxidation and sorption of highly toxic Sb(III) using a dual-functional electroactive filter.

One of the topics gaining lots of recent attention is the antimony (Sb) pollution. We have designed a dual-functional electroactive filter consisting of one-dimensional (1-D) titanate nanowires and carbon nanotubes for simultaneous oxidation and sorption of Sb(III). Applying an external limited DC voltage assist the in-situ conversion of highly toxic Sb(III) to less toxic Sb(V).

Properties and Mechanism of Hydroxyapatite Coating Prepared by Electrodeposition on a Braid for Biodegradable Bone Scaffolds.

Hydroxyapatite (HA) coating is successfully prepared by electrodeposition on the surface of polyvinyl alcohol (PVA)/polylactic acid (PLA) braid which serves as a potential biodegradable bone scaffold. The surface morphology, element composition, crystallinity and chemical bonds of HA coatings at various deposition times (60, 75, 90, 105 and 120 min) are characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Average Surface roughness (Ra) of HA coating is observed by confocal microscopy.

PP/TiO Melt-Blown Membranes for Oil/Water Separation and Photocatalysis: Manufacturing Techniques and Property Evaluations.

This study aims to produce polypropylene (PP)/titanium dioxide (TiO) melt-blown membranes for oil/water separation and photocatalysis. PP and different contents of TiO are melt-blended to prepare master batches using a single screw extruder. The master batches are then fabricated into PP/TiO melt-blown membranes.

Synthesis, characterization and excellent antibacterial property of cellulose acetate reverse osmosis membrane via a two-step reaction.

In order to improve the antibacterial efficiency and spectrum of cellulose acetate reverse osmosis membrane (CA-RO), both quaternary ammonium and bromoacetyl groups were introduced into cellulose diacetate under mild conditions forming CA-RO with bi-antibacterial groups for seawater desalination. Bromoacetyl bromide and a series of tertiary amine were chosen as the modification agents respectively. The characterization results showed that both two antibacterial groups were successfully introduced with a certain density.

An All-Inorganic Colloidal Nanocrystal Flexible Polarizer.

Inorganic single crystals with anisotropic structures usually suffer from high brittleness and stiffness. Flexible polymers are used to replace inorganic crystals, but the hot-stretching-induced orientation process is tedious, and oriented molecular chains tend to revert to random coils during aging. To overcome these obstacles and using the similarities between sub-1 nm nanowires (NWs) and linear polymers, we successfully fabricated anisotropic, transparent, flexible, and stable (ATFS) NW films with great potential for optical applications through a wet-spinning method.

Highly Chemically Stable MOFs with Trifluoromethyl Groups: Effect of Position of Trifluoromethyl Groups on Chemical Stability.

Metal-organic frameworks (MOFs) are a class of advanced porous crystalline materials. However, numerous MOFs have poor chemical stability, significantly restricting their industrial application. The introduction of trifluoromethyl groups around clusters of MOFs results in a shielding effect caused by their hydrophobicity and bulkiness, thus preventing guest molecules from attacking the coordination bonds.

Minimum Connected Dominating Set Algorithms for Ad Hoc Sensor Networks.

To achieve effective communication in ad hoc sensor networks, researchers have been working on finding a minimum connected dominating set (MCDS) as a virtual backbone network in practice. Presently, many approximate algorithms have been proposed to construct MCDS, the best among which is adopting the two-stage idea, that is, to construct a maximum independent set (MIS) firstly and then realize the connectivity through the Steiner tree construction algorithm. For the first stage, this paper proposes an improved collaborative coverage algorithm for solving maximum independent set (IC-MIS), which expands the selection of the dominating point from two-hop neighbor to three-hop neighbor.

Fe-Mn-Ce oxide-modified biochar composites as efficient adsorbents for removing As(III) from water: adsorption performance and mechanisms.

In this study, a novel Fe-Mn-Ce oxide-modified biochar composite (FMCBC) was synthesized via pyrolysis to enhance the adsorption capacity of biochar (BC). Scanning electron microscopy-energy-dispersive X-ray spectroscopy confirmed that Fe, Mn, and Ce were successfully loaded onto the surface of the BC. A series of adsorption experiments showed that the FMCBC exhibited improved adsorption of As(III) in an aqueous environment.

Effects of di-n-butyl phthalate on photosynthetic performance and oxidative damage in different growth stages of wheat in cinnamon soils.

Herein, we investigated the effects of di-n-butyl phthalate (DBP) on photosynthesis, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) content, oxidative damage, and biomass accumulation of different tissues in wheat (Triticum aestivum L) planted in cinnamon soils. The photosynthetic or fluorescence parameters (except for the intercellular carbon dioxide concentration), chlorophyll content, RuBisCO content, and biomass of roots, stems, and leaves decreased at the seedling, jointing, and booting stages under the stress of DBP. Compared with the control, the content of superoxide anions and hydrogen peroxide in the roots, stems, and leaves increased with increasing DBP concentrations at the seedling, jointing, and booting stages.

Decreased cross-linking in interfacial polymerization and heteromorphic support between nanoparticles: Towards high-water and low-solute flux of hybrid forward osmosis membrane.

Realizing that one main factor affecting development of forward osmosis (FO) membrane was internal concentration polarization (ICP), graphene oxide (GO) with two-dimensional structure and oxidized carbon nanotubes (OCNTs) with one-dimensional structure were linked by oxygen-containing groups to form water channels in the polyamide layer. OCNTs and GO were used for producing reactions among oxygen-containing groups of nanoparticles and polymer chains, and oxygen-containing groups were fully exposed because GO and OCNTs restrained aggregation. Decrease of cross-linking degree for interfacial polymerization layer was confirmed due to reaction from GO/OCNTs/m-phenylene diamine/1,3,5-benzenetricarbonyl trichloride.

Fabric Composites Reinforced with Thermally Bonded and Irregularly Aligned Filaments: Preparation and Puncture Resistant Performance.

This study proposes fabric composites with improved static and dynamic puncture via increasing a friction force to restrain the slide of filaments as well as the compression and abrasion between the fibers and the puncture probe. The the bi-layered shell layers of composite fabrics are composed of aramid staple fibers and nylon staple fibers and a layer of low-melting-point polyester (LPET). The nonwoven layer consisting of recycled aramid and nylon staple fibers provides a shear effect to dissipate part of the puncture energy.

Membrane fouling control by Ca during coagulation-ultrafiltration process for algal-rich water treatment.

Seasonal algal bloom, a water supply issue worldwide, can be efficiently solved by membrane technology. However, membranes typically suffer from serious fouling, which hinders the wide application of this technology. In this study, the feasibility of adding Ca to control membrane fouling in coagulation-membrane treatment of algal-rich water was investigated.

An efficient method for noninvasive prenatal diagnosis of fetal trisomy 13, trisomy 18, and trisomy 21.

Background: Molecular size determination of circulating free fetal DNA in maternal plasma is an important detection method for noninvasive prenatal testing (NIPT). The fetal DNA molecule is the primary factor determining the overall performance of NIPT and its clinical interpretation. The proportion of cell-free fetal DNA molecules is expressed as the fetal DNA fraction in the plasma of pregnant women.

Specific K Binding Sites as CO Traps in a Porous MOF for Enhanced CO Selective Sorption.

Metal-organic frameworks (MOFs) can be fine-tuned to boost sorbent-sorbate interactions in order to improve gas sorption and separation performance, but the design of MOFs with ideal structural features for gas separation applications remains a challenge. Herein it is reported that unsaturated alkali metal sites can be immobilized in MOFs through a tetrazole based motif and that gas affinity can thereby be boosted. In the prototypal MOF of this type-NKU-521 (NKU denotes Nankai University), K cations are effectively embedded in a trinuclear Co -tetrazole coordination motif.

Microstructure and Properties of Self-Assembly Graphene Microcapsules: Effect of the pH Value.

Graphene has attracted attention in the material field of functional microcapsules because of its excellent characteristics. The content and state of graphene in shells are critical for the properties of microcapsules, which are greatly affected by the charge adsorption equilibrium. The aim of this work was to investigate the effect of pH value on the microstructure and properties of self-assembly graphene microcapsules in regard to chemical engineering.

Synthesis and Performances of Phase Change Microcapsules with a Polymer/Diatomite Hybrid Shell for Thermal Energy Storage.

The mechanical behavior of phase-change microcapsules (microPCMs) is of vital significance for practical applications in thermal energy storage. Hence, a new type of microPCMs based on an n-octadecane (C18) core and a melamine-urea-formaldehyde (MUF)/diatomite hybrid shell was developed through in situ polymerization. Based on SEM micrographs, most microPCMs exhibited a nearly spherical and smooth microstructure, with broadened particle size distributions.

Novel Bacterial Cellulose/Gelatin Hydrogels as 3D Scaffolds for Tumor Cell Culture.

Three-dimensional (3D) cells in vitro culture are becoming increasingly popular in cancer research because some important signals are lost when cells are cultured in a two-dimensional (2D) substrate. In this work, bacterial cellulose (BC)/gelatin hydrogels were successfully synthesized and were investigated as scaffolds for cancer cells in vitro culture to simulate tumor microenvironment. Their properties and ability to support normal growth of cancer cells were evaluated.

Multi-Jet Electrospinning with Auxiliary Electrode: The Influence of Solution Properties.

Multiple jets ejection in electrospinning has been a major approach to achieving a high production rate of ultrafine fibers, also known as nanofibers. This work studies the effect of solution parameters-including dielectric constant, polarity, conductivity and surface tension-on the jet number and jet evolution in the auxiliary electrode electrospinning approach. The results show that it is easier to generate 2⁻6 jets with short stable jet length (1.

Reactive Pad-Steam Dyeing of Cotton Fabric Modified with Cationic P(St-BA-VBT) Nanospheres.

The Poly[Styrene-Butyl acrylate-(P-vinylbenzyl trimethyl ammonium chloride)] P(St-BA-VBT) nanospheres with N⁺(CH₃)₃ functional groups were successfully prepared and applied to modify cotton fabrics using a pad-dry process. The obtained cationic cotton fabrics were dyed with pad-steam dyeing with reactive dye. The results show that the appropriate concentration of nanospheres was 4 g/L.

Properties and Fabrication of PA66/Surface-Modified Multi-Walled Nanotubes Composite Fibers by Ball Milling and Melt-Spinning.

PA66/surface-modified multi-walled carbon nanotubes (MWNTs) composite fibers with a better dispersion and a stronger interfacial interaction between MWNTs and polyamide 66 (PA66) matrix were fabricated via the method of ball milling and melt-spinning. The effects of unmodified (U-MWNTs), acid-modified (MWNTs-COOH) and sodium dodecyl benzenesulfonate-modified MWNTs (MWNTs-SDBS) on the physical mechanical and thermal properties of PA66 were investigated. The results show that, the surface modified nanotube can provide homogeneous dispersion and there is a strong interfacial bonding between PA66 and MWNTs-COOH.

Effects of Fatty Acid Anhydride on the Structure and Thermal Properties of Cellulose-g-Polyoxyethylene (2) Hexadecyl Ether.

Cellulose was premodified by short-chain fatty acid anhydrides, such as acetic anhydride (CA), propionic anhydride (CP), and butyric anhydride (CB), followed by grafting of polyoxyethylene (2) hexadecyl ether (E₂C) using toluene-2,4-diisocyanate as a coupling agent. The feeding molar ratio of E₂C and the anhydroglucose unit (AGU) was fixed at 4:1, and then a series of CA-g-E₂C, CP-g-E₂C, and CB-g-E₂C copolymers were successfully prepared. The structures and properties of the copolymers were characterized using FTIR (fourier transform infrared spectra), ¹H-NMR (Proton nuclear magnetic resonance), DSC (Differential scanning calorimeter), POM (polarized light microscopy), TGA (thermogravimetric analysis) and WAXD (wide-angle X-ray diffraction).

Novel Ultrafine Fibrous Poly(tetrafluoroethylene) Hollow Fiber Membrane Fabricated by Electrospinning.

Novel poly(tetrafluoroethylene) (PTFE) hollow fiber membranes were successfully fabricated by electrospinning, with ultrafine fibrous PTFE membranes as separation layers, while a porous glassfiber braided tube served as the supporting matrix. During this process, PTFE/poly(vinylalcohol) (PVA) ultrafine fibrous membranes were electrospun while covering the porous glassfiber braided tube; then, the nascent PTFE/PVA hollow fiber membrane was obtained. In the following sintering process, the spinning carrier PVA decomposed; meanwhile, the ultrafine fibrous PTFE membrane shrank inward so as to further integrate with the supporting matrix.

Novel Dual-Component Microencapsulated Hydrophobic Amine and Microencapsulated Isocyanate Used for Self-Healing Anti-Corrosion Coating.

Dual component microencapsulated hydrophobic amine and microencapsulated isocyanate were designed and fabricated for self-healing anti-corrosion coating. In this system, novel hydrophobic polyaspartic acid ester (PAE) and isophorone diisocyanate (IPDI) were microencapsulated respectively with melamine-formaldehyde (MF) as shell via in situ polymerization. To reduce the reaction activity between shell-forming MF prepolymer and PAE, another self-healing agent tung oil (TO) was dissolved in PAE and subsequently employed as core material.