Preparation of SA-g-(PAA-co-PDMC) polyampholytic superabsorbent polymer and its application to the anionic dye adsorption removal from effluents

"Seaweed Structure" design for solid gel electrolyte with hydroxide ion conductivity enabling flexible zinc air batteries

The construction of solid-state electrolytes for flexible zinc-air batteries is extremely challenging. A flexible and highly conductive solid electrolyte designed with a "seaweed structure" is reported in this work. Sodium alginate serves as the backbone to form a robust network structure, and the grafted quaternary ammonium groups provide channels for rapid ion transport, achieving excellent flexibility and hydroxide conductivity. The conductivity of the modified electrolyte membrane (QASA) is 5.23 × 10-2 S cm-1 at room temperature and reaches up to 8.51 × 10-2 S cm-1 at 75 °C. In the QASA based battery, bending at any angle is realized, and the power density is up to 57.28 mW cm-2. This work provides a new way to prepare high conductivity, green solid-state zinc-air batteries, and opens up a research line of thought for flexible energy storage materials.

Studying removal of anionic dye by prepared highly adsorbent surface hydrogel nanocomposite as an applicable for aqueous solution

In this study, a Sodium alginate-g-poly (acrylamide-clay)/TiO2 hydrogel nanocomposite [SA-g-p(AM-Bn)/TiO2] was synthesized using the biopolymer sodium alginate (SA), acrylamide (AM), and bentonite clay (Bn) as hybrid materials embedded with titanium dioxide nanoparticles (TiO2NPs) for the removal of toxic Congo Red (CR) dye from an aqueous solution. The [SA-g-p(AM-Bn)/TiO2] nanocomposite has been described on the basis of thermal stability, morphological analysis, estimation of functional group, and crystalline/amorphous character by TGA, EFSEM/EDX, TEM, FT-IR, and XRD analysis, respectively. The effects of operational parameters toward the CR dye adsorption on [SA-g-p(AM-Bn)/TiO2], including contact time, adsorbent dosage, initial concentration, initial pH, and temperature were investigated. The maximum adsorption efficiency was found to be 185.12 mg/g for [SA-g-p(AM-Bn)/TiO2] in 100 mg/L of solution CR at pH 6.0 within 1 h. The equilibrium isotherms, kinetics, and thermodynamics parameters of adsorption were examined, and results showed that the isotherm fitted the Freundlich model and the kinetics adsorption model of CR followed pseudo-first-order, thus indicating physisorption of anionic-CR onto the sorbent due to the development of an electrostatic attraction bond. Thermodynamic parameters for [SA-g-p(AM-Bn)/TiO2] have values (ΔG and ΔH) reflecting the spontaneous and endothermic nature of the adsorption processes. Moreover, [SA-g-p(AM-Bn)/TiO2] presented outstanding excellent reusability and recyclability with a relatively best removal percentage as compared to [SA-g-p(AM-Bn)] and suggested their applicability towards the textile industry and water purification purposes.

Stimuli-Responsive Ion Adsorbents for Sustainable Separation Applications

Stimuli-responsive ion absorbents (SRIAs) with reversible ion adsorption and desorption properties have recently attracted immense attention due to their outstanding functionalities for sustainable separation applications. Over the past decade, a series of SRIAs that respond to single or multiple external stimuli (e.g., pH, gas, temperature, light, magnetic, and voltage) have been reported to achieve excellent ion adsorption capacity and selectivity while simultaneously allowing for their reusability. In contrast to traditional adsorbents that are mainly regenerated through chemical additives, SRIAs allow for reduced chemical and even chemical-free regeneration capacities, thereby enabling environmentally friendly and energy-efficient separation technologies. In this review, we systematically summarize the materials and strategies reported to date for synthesizing single-, dual-, and multiresponsive ion adsorbents. Following a discourse on the fundamental mechanisms that govern their adsorption and desorption under various external stimuli, we provide a concise discussion of the regeneration capacity and application of these responsive ion adsorbents for sustainable water desalination, toxic ion removal, and valuable ion extract and recovery. Finally, we discuss the challenges in developing and deploying these promising multifunctional responsive ion adsorbents together with strategies to overcome these limitations and provide prospects for their future.

Preparation of Polyoxometalate-Based Composite by Solidification of Highly Active Cobalt-Containing Polytungstate on Polymeric Ionic Liquid for the Efficient Isolation of Proteinase K

A novel porous polyoxometalate (POM)-based composite (Co₄PW-PDDVAC) was prepared via the solidification of water-soluble polytungstate (Co₄PW) on the polymeric ionic liquid dimethyldodecyl-4-polyethylene benzyl ammonium chloride (PDDVAC) via a cation-exchange reaction. The solidification was confirmed by EDS, SEM, FT-IR, TGA, and so on. The strong covalent coordination and hydrogen-bonding interaction between the highly active Co²⁺ of the Co₄PW and the aspartic acid residues of proteinase K endowed the obtained Co₄PW-PDDVAC composite with excellent proteinase K adsorption properties. Thermodynamic investigations indicate that the adsorption behavior of proteinase K was consistent with the linear Langmuir isothermal model, giving an adsorption capacity as high as 1428 mg g^-1. The Co₄PW-PDDVAC composite was applied in the selective isolation of highly active proteinase K from Tritirachium album Limber crude enzyme fluid.

Environmentally friendly hydrogel: A review of classification, preparation and application in agriculture

Superabsorbent hydrogel (SH) is three-dimensional (3D) cross-linked hydrophilic polymer that can absorb and retain large quantities of water or other aqueous solutions. SH is made of water-affinity monomers and is widely used in biomedicine, wastewater treatment, hygiene and slow-release fertilizers (SRFs). This article focused on the preparation methods of SH, superabsorbent hydrogel composite and the application of SH in agriculture. By selecting various synthetic technologies and cross-linking agents, a series of chemical cross-linking or physical networks can be designed and tailored to meet specific applications. In view of the excellent characteristics of water absorption, biodegradability, water retention and slow-release capacity, SH occupies a dominant position in the SRFs market. In this work, the agricultural application of SH in double coated SRFs and nutrients carriers is also discussed. Some mechanisms related to the nutrient release were analyzed by mathematical models. In addition, some agronomic benefits of using superabsorbent hydrogels in improving water absorption, water holding capacity and increasing crop yields were also discussed. Although SH has certain shortcomings, from the perspective of long-term development, it will further show great potential in sustainable agriculture.

Simultaneous adsorption and oxidation of Sb(III) from water by the pH-sensitive superabsorbent polymer hydrogel incorporated with Fe-Mn binary oxides composite

In this work, the superabsorbent polymer hydrogel (SPH) of Poly(potassium acrylate-co-acrylamide (PPAA)) incorporated with Fe-Mn binary oxides (FMBOs) was synthesized and used for the removal of Sb(III) from water. Characterization analysis proved that FMBO₃ was successfully encapsulated into the SPH. The Fe/Mn oxide species in the composite SPH comprised FeO(OH), Fe₂O₃, MnO(OH), and MnO₂. The functional groups including N-H, -OH, carboxy as well as Fe atoms were confirmed adsorption sites through ligand exchange and inner-sphere complexes formation. Mn oxides can partially oxidize Sb(III) to Sb(V). Compared with the pseudo-first-order model, the pseudo-second-order model could better describe the adsorption kinetics. And the swelling degree of the composite SPH had a positive impact on the removal rate. The Langmuir-Freundlich model was the most suitable isotherm model to analyze the experimental data. According to thermodynamic parameters, the adsorption process was a spontaneous exothermic reaction. The maximum adsorption capacity of the composite SPH for Sb(III) could be up to 105.59 mg/g at 288 K. In addition, a stable removal rate can be achieved over a wide pH range of 3-10, with little metal leaching even under acidic conditions. Furthermore, coexisting ions and DOM displayed an insignificant influence on the adsorption of Sb(III).

Kinetic and thermodynamic studies of the biosorption of Cr (VI) in aqueous solutions by Agaricus campestris

In the present study, biomass of Agaricus campestris was tested to evaluate its effectivity as a biosorbent for the removal of Cr (VI) ions from aqueous solutions. The influence of various process parameters such as pH, temperature, contact time, biosorbent dosage and desorption were studied. Pseudo-first order, pseudo-second order, Ritchies and intraparticle diffusion model were used to present the adsorption kinetics. Results obtained indicate that the adsorption process is fast and spontaneous within the first 60 min. The experimental data supports pseudo-second order model. The sorption data conformed well to the Langmuir isotherm model. The maximum adsorption capacity (q _max) onto A. campestris was 56.21 mg g^-1 for Cr(VI) at 45°C when 0.1 g biomass was used. In addition, the mean values of thermodynamic parameters of standard free energy (ΔG⁰= -1.635 kJ mol^-1 at 45°C), standard enthalpy (ΔH⁰= -9.582 kJ mol^-1) and standard entropy (ΔS⁰= -24.992 J mol^-1K^-1) of the adsorption mechanism were determined.

Study on Seed Emergence and Seedling Growth of Artemisia Desertorum with Superabsorbent Polymers

In this study, the emergence rate, emergence potential, root length, stem length, water consumption, and biomass around a root system were used as evaluation indexes, and we used the laboratory-prepared super absorbent resin watermelon rind (WMR)-p (AA-co-DAAM) (superabsorbent polymer 1-SAP₁), WMR-p (AA-co-DAAM)/palygorskite (PGS) (SAP₂) in a laboratory and commercially available water-retaining agents (SAP_RX and SAP_HDB) to assist the emergence of Artemisiadesertorum seeds and seedling growth; then, their water absorption and thermal stability were discussed. The results showed that the thermal stability of an SAP prepared in the laboratory and the water consumption during seed emergence, root length, and stem length after emergence were better than those of an SAP purchased on the market, and this information could help to promote the emergence and seedling growth of Artemisiadesertorum. While enhancing the drought resistance of plants, using a laboratory-produced SAP can effectively reduce the number of artificial irrigations.

Effective Decolorization of Rhodamine B by a Ti Foam-Based Photocatalytic Membrane Reactor

In this study, a Ti foam-based photocatalytic membrane reactor (PMR) was constructed for rhodamine B (RhB) wastewater decolorization. Ti foam was chosen as a membrane and visible-light-driven C₃N₄ was chosen as a photocatalyst. The results showed that the decolorization efficiency could be up to 100% with a flow rate of 6.93 mL/min when the PMR was applied in the treatment of a 30 mg/L RhB solution and the concentration of C₃N₄ was 1 g/L. pH played an important role in the decolorization performance of the PMR. Alkalinity was not conducive to the decolorization of RhB in the PMR, which was mainly due to the property that RhB was difficult to dissolve in an alkaline solution. Membrane fouling was mainly caused by a C₃N₄ photocatalyst, while the effect of RhB on membrane fouling was negligible. Membrane fouling could be retarded when the PMR was applied for RhB treatment under visible-light irradiation, which was because of photoinduced hydrophilicity of C₃N₄. The membrane flux could be restored to its initial values after simple ultrasonic cleaning and backwashing. This was due to the large difference between the pore size of Ti foam and the particle size of C₃N₄ and the super hydrophilicity of Ti foam and C₃N₄.

Synthesis, characterization and flocculation performance of a novel sodium alginate-based flocculant

In this study, a natural polymer-based organic flocculant (sodium alginate-methacrylatoethyl trimethyl ammonium chloride, SA-PDMC) was synthesized by graft copolymerization. The optimum preparation procedures were determined by single factor experiments. The flocculation behaviors of SA-PDMC were investigated in humic acid (HA) and kaolin suspension considering the effects of flocculant doses and initial pH. The results indicated that charge neutralization and bridging action played an important role in the removals of HA and kaolin. Also, SA-PDMC performed well in a wide pH range of 5.0-10.0. Besides, SA-PDMC, as polyaluminium (PAC) aid, was investigated in the lake water treatment. The ratio of PAC and SA-PDMC was optimized through response surface methodology based on a central composite design. Results showed that SA-PDMC and PAC have a strong synergy, under optimal conditions SA-PDMC can reduce the dose of PAC by 40 % while ensuring the water quality.

Synthesis and characteristics of a novel dust suppressant with good weatherability for controlling dust in open coal yards

This study aims to synthesize a dust suppressant for controlling coal dust pollution in open yards using natural polymers. Guided by graft copolymerization theory, potassium persulfate acts as an initiator to excite the free radicals of collagen and sodium alginate, allowing them to combine with acrylic acid and acrylamide to form a new polymer. The TG curve indicates that the thermal stability of the polymer is superior to that of the raw material. Scanning electron microscope (SEM) images show that the product can reduce the generation of dust by bonding the pulverized coal. With CCD method, when the monomer concentration increases in a certain range, the cohesive ability of the product to coal increases first and then decreases. Initiators and crosslinkers showed the same pattern. A series of performance experiments show that the product has a dust suppression rate of 98.7% at a wind speed of 14 m/s, and maintain one of 94.5% at a wind speed of 8 m/s after a rainstorm. In addition, there was no significant loss in dust suppression performance and compressive strength of the solidified layer after wind and rain. Sunlight, low temperature, and high temperature have little influence on the dust suppression effect of the product, which indicates that the product has better weather resistance and helps to suppress dust for a longer time in open air conditions.

Synthesis of anionic ionic liquids@TpBd-(SO3)2 for the selective adsorption of cationic dyes with superior capacity

Anionic ionic liquids@covalent organic materials for the selective adsorption of cationic dyes.

One-pot synthesis of multi-functional and environmental friendly tannic acid polymer with Fe3+ and formaldehyde as double crosslinking agents for selective removal of cation pollutants

A novel multi-functional and environmental friendly tannic acid polymer (Fe³⁺-TA-HCHO) with Fe³⁺ and formaldehyde as double crosslinking agents together with cysteine as heteroatom source was prepared by a one-pot hydrothermal method. Characterization with transmission electron microscope (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR), and elemental analysis demonstrated that the Fe³⁺-TA-HCHO possessed uniform structure and particle size as well as plentiful functional groups. The resulted Fe³⁺-TA-HCHO material as a adsorbent to remove methylene blue, sunset yellow, Pb²⁺, Hg²⁺, and AsO₃^3- from water. The results suggested that Fe³⁺-TA-HCHO polymer (pHpzc is 2.33) showed different adsorption properties for anionic pollutants (sunset yellow and AsO₃^3-) and cationic pollutants (methylene blue, Pb²⁺, and Hg²⁺). The material exhibited remarkable selectivity for adsorption and separation of pollutants. The maximum adsorption capacities calculated from Langmuir model for methylene blue, Pb²⁺, and Hg²⁺ were 154.32, 819.67, and 699.30 mg g^-1, respectively. This is the first time that tannic acid polymer is synthesized by double crosslinking method, which not only developed a promising adsorbent for selective removal of cation pollutants, but also opened up a new avenue for synthesis and application of tannic acid polymer.

The Adsorption of Methylene Blue by an Amphiphilic Block Co-Poly(Arylene Ether Nitrile) Microsphere-Based Adsorbent: Kinetic, Isotherm, Thermodynamic and Mechanistic Studies

Dye pollution is a serious problem in modern society. We desired to develop an efficient adsorbent for the decontamination of discharged dyes. In this work, the polymeric microspheres derived from a kind of amphiphilic block of co-poly(arylene ether nitrile) (B-b-S-P) were prepared on the basis of “oil-in-water” (O/W) microemulsion method. The B-b-S-P microspheres were found competent to remove the cationic dye, methylene blue (MB); and various influential factors, such as contact time, initial concentration, solution pH and temperature were investigated. Results indicated that the maximum adsorption capacity of B-b-S-P microspheres for MB was 119.84 mg/g at 25 °C in neutral conditions. Adsorption kinetics and isotherm dates were well fitted to a pseudo-second-order kinetic model and the Langmuir isotherm model, and thermodynamic parameters implied that the adsorption process was endothermic. The B-b-S-P microspheres also exhibited a highly selective adsorption for cationic dye MB, even in the presence of anionic dye methyl orange (MO). In addition, the possible adsorption mechanism was studied, suggesting that the electrostatic interaction and π–π interaction could be the main force in the adsorption process.

The Fabrication of Calcium Alginate Beads as a Green Sorbent for Selective Recovery of Cu(Ⅱ) from Metal Mixtures

Calcium alginate (CA) beads as a green sorbent were easily fabricated in this study using sodium alginate crosslinking with CaCl2, and the crosslinking pathway was the exchange between the sodium ion of α-L-guluronic acid and Ca(II). The experimental study was conducted on Cu(II), Cd(II), Ni(II) and Zn(II) as the model heavy metals and the concentration was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The characterization and sorption behavior of the CA beads were analyzed in detail via using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The adsorption experiments demonstrated that the CA beads exhibited a high removal efficiency for the selective adsorption of Cu(II) from the tetra metallic mixture solution and an excellent adsorption capacity of the heavy metals separately. According to the isotherm studies, the maximum uptake of Cu(II) could reach 107.53 mg/g, which was significantly higher than the other three heavy metal ions in the tetra metallic mixture solution. Additionally, after five cycles of adsorption and desorption, the uptake rate of Cu(II) on CA beads was maintained at 92%. According to the properties mentioned above, this material was assumed to be applied to reduce heavy metal pollution or recover valuable metals from waste water.

Construction of magnetic lignin-based adsorbent and its adsorption properties for dyes

The magnetic lignin-based adsorbent (Fe₃O₄/C-ACLS) has been successfully prepared and applied to adsorbing azo dyes Congo red, Titan yellow and Eriochrome blue black R. The samples were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray powder diffraction (XRD), vibration sample magnetometer (VSM), Raman spectroscopy and elemental analysis. In the process of adsorption, five kinds of influencing factors and recycling regeneration were discussed, and the adsorption mechanisms such as kinetics, isotherm, thermodynamics were explored. The results show that Fe₃O₄/C-ACLS can remove 98%, 92% and 99% of Congo red, Titan yellow and Eriochrome blue black R, respectively. Under the same conditions, the removal rate was 87%, 84% and 88% after 5 times adsorption cycle, respectively. Pseudo-first-order, pseudo-second-order kinetics, Elovich model and intraparticle diffusion model were studied, and the results show that the adsorption process conforms to pseudo-second-order kinetics model, and the diffusion rate is controlled by many steps. The results of isotherm model and thermodynamics show that the adsorption process is consistent with Langmuir model and is mainly a spontaneous chemical endothermic process of monolayer.

Fuzzy Optimization on the Synthesis of Chitosan-Graft-Polyacrylic Acid with Montmorillonite as Filler Material: A Case Study

In this paper, the synthesis of a chitosan–montmorillonite nanocomposite material grafted with acrylic acid is presented based on its function in a case study analysis. Fuzzy optimization is used for a multi-criteria decision analysis to determine the best desirable swelling capacity (Y_Q) of the material synthesis at its lowest possible variable cost. For Y_Q, the integrating the result’s cumulative uncertainty is an essential element to investigate the feasibility of the developed model equation. The Pareto set analysis is able to set the appropriate boundary limits for Y_Q and the variable cost. Two case studies are presented in determining the lowest possible cost: Case 1 for maximum Y_Q, and Case 2 for minimum Y_Q. These boundary limits were used in the fuzzy optimization to determine its global optimum results that achieved the overall satisfaction ratings of 67.2% (Case 1) and 52.3% (Case 2). The synthesis of the polyacrylic acid/chitosan material for Case 1 resulted in 305 g/g Y_Q and 10.8 USD/kg, while Case 2 resulted in 97 g/g Y_Q and 12.3 USD/kg. Thus, the fuzzy optimization approach proves to be a practical method for examining the best possible compromise solution based on the desired function to adequately synthesize a material.

Bioinspired catecholamine/starch composites as superadsorbent for the environmental remediation

Focusing on the encouraging properties of starch-based composite materials, starch‑g‑(acrylic acid‑co‑acrylamide) superabsorbent was synthesized using solution polymerization method, and then the catecholamine functional groups were introduced on to pore surface of the absorbent via oxidative polymerization of dopamine (DA). The adsorbent was optimized in terms of the monomers' mass ratio and synthesis conditions, and characterized by different characterization techniques. The polydopamine (PDA) coating thickness was estimated using transmission electron microscopy (TEM) image and it was found to be 83 nm. The bimodal mesoporous adsorbent with 5914.66% swelling ratio bearing micropores with a specific surface area of 2.8031 m² g^-1 was used for the adsorption of methylene blue (MB) as a model water pollutant dye. The maximum adsorption capacity was obtained 2276 mg g^-1 at pH 9 and within 100 min. The adsorbent with unprecedented super high adsorption capacity can be encouraging from different environmental remediation points of view.

Extracellular polymeric substances (EPS) modulate adsorption isotherms between biochar and 2,2',4,4'-tetrabromodiphenyl ether

Extracellular polymeric substances (EPS), chars and persistent organic pollutants (POPs) frequently coexist in the environment. However, a knowledge gap exists regarding their interactions. Therefore, we applied 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) as a model POP to investigate the influence of bovine serum albumin (BSA) and sodium alginate (SA) - representing protein and polysaccharide components of EPS - on POP adsorption to biochars. Surface activities of tested biochars were characterised using nuclear magnetic resonance, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The adsorption capacities of BDE-47 on biochars were significantly improved by both EPS analogues: BSA at concentrations of only 5 mg L^-1 and SA at 80 mg L^-1 at c_e = 1 S_w BDE-47 concentration. However, 80 mg L^-1 BSA decreased the BDE-47 adsorption capacities on biochars at the tested BDE-47 concentrations. Chemisorption and pore filling mechanisms appeared to dominate the adsorption process of BDE-47 on maize straw and wheat straw biochars. After adding BSA (or SA), a hydrophobic partition effect was found to best explain the adsorption process and linearity of adsorption was enhanced. These results progress our understanding of bioavailability and migration of POPs: especially relevant to the water industry and biochar/EPS facilitated removal of these contaminants.

Preparation of Sulfonated Poly(arylene ether nitrile)-Based Adsorbent as a Highly Selective and Efficient Adsorbent for Cationic Dyes

In this work, a highly selective and efficient polymer adsorbent inspired by a water-soluble sulfonated poly(arylene ether nitrile) (SPEN) was successfully synthesized. Due to the distinct structure of functional carboxyl, sulfonic acid and rigid benzene rings, a facile aluminium (III) ions crosslinking method was employed to fabricate the SPEN-based adsorbents (SPEN-Al). Among the three adsorbents, SPEN-Al-2 exhibited superior adsorption capacities with uniform morphology. Subsequently, the SPEN-Al-2 was selected as the adsorbent for three cationic dyes (rhodamine B (Rh B), neutral red (NR), methylene blue (MB)) and three anionic dyes (orange G (OG), methyl orange (MO), acid fuchsin (AF)), respectively, demonstrating that the adsorbent possessing excellent selectivity toward cationic dyes. Moreover, the dye's adsorption selectivity of SPEN-Al-2 was further certificated in a binary cationic-anionic dyes mixtures (MB/OG and MB/MO) system. Taking MB as a dye model, a series of factors (contact time, concentration, temperature and pH) and adsorption models were systematically investigated in dye adsorption experiments. Results indicated that the adsorption was endothermic and the maximum adsorption capacity of SPEN-Al-2 could reach up to 877.5 mg/g; pseudo-second-model and Langmuir model were fitted to the adsorption kinetics and equilibrium isotherm, respectively, manifesting that SPEN-Al adsorbent was promising in the dyes removing field.

Multifunctional negatively-charged poly (ether sulfone) nanofibrous membrane for water remediation

Multifunctional materials, which can effectively and simultaneously remove various water-soluble contaminants like dyes and heavy metal ions, and separate oil from water, are urgent to meet increasing challenges on wastewater remediation. Herein, a cross-linked poly (acrylic acid) (PAA) modified poly (ether sulfone) nanofibrous membrane (NFM) was fabricated by a facile in-situ pre-reaction followed by electrospinning. The as-prepared NFM showed excellent hydrophilicity and underwater lipophobicity, therefore expressed excellent water permeability with high water flux (about 5142 L m² h^-1). As a result, under solely driven by gravity, the NFM was capable to separate emulsified oil/water emulsion and a wide range of oil/water mixtures. Moreover, repeating separation tests indicated that the NFM had great long-term sustainability even after ten separation cycles. In addition, due to the introduction of PAA and the large surface-to-volume ratio, the NFM also expressed rapid adsorption capacity for cationic dyes as well as heavy metal ions; thus could simultaneously remove these contaminants during the oil/water separation process. Furthermore, the NFM could be also decorated by Ag NPs to endow the membranes with remarkable antibacterial ability against both E. coli and S. aureus. Our findings strongly suggested that the multifunctional NFM may have great potential in treating complicated wastewater.

Identify the Active Phase of Fe–CN Composites for Oxidation Removal of Rhodamine B with H2O2

Fe-containing carbon nitrides (Fe–CN) prepared with various CN precursors, including dicyandiamide, melamine, guanidine hydrochloride and urea, were characterized by X-ray diffraction, thermal gravimetric analysis, N2 physisorption, transmission electron microscopy, X-ray photoelectron spectroscopy and atomic emission spectrometer measurements, and used as catalysts to catalyze the rhodamine B oxidation with H2O2 as oxidant. Characteristic results showed that Fe–CN exhibits different compositions, properties and catalytic performances if different CN precursors are used. The Fe–CN prepared from dicyandiamide contains mainly CN phase and certain amounts of surface Fe2O3 phase, exhibits the best activity; while that prepared from urea contains mainly Fe2O3 phase and few amounts of CN phase, exhibits the worst activity. Contrasting experiments conducted under light irradiation, with a supported Fe/CN_D catalyst, and that using a washed catalyst, suggested that the surface Fe2O3 is the active site of the reaction.

Effects of eco-friendly carbohydrate-based superabsorbent polymers on seed germination and seedling growth of maize

Desertification is the degradation of land in arid and semi-arid areas. Nowadays, lack of water and desertification are extreme problems for plant survival and growth in the arid and semi-arid areas of the world. It becomes increasingly important as to how to let the plant absorb moisture more effectively for keeping growth strong. We synthesized superabsorbent polymers (SAPs) with carbohydrate and characterized them by Fourier transform infrared spectra analyses, scanning electron microscopy and thermogravimetric/differential thermal analyses. Then, a completely randomized experiment was conducted to assess the effect of carbohydrate-based SAPs on seed germination and seedling growth of maize in an artificial climate chest. The results showed that adding an appropriate amount of SAPs could improve root length, shoot length, total biomass, germination potential and germination rate. It indicates that this SAP is not toxic to plants and can promote seed germination, and at the same time provides a possibility of replacing other substrates.

Adsorption behavior and mechanism of β-cyclodextrin–styrene-based polymer for cationic dyes

These figures show that the cyclodextrin polymer was synthesized successfully and possessed good thermal stability.