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The use of recycling materials from demolished concrete as raw material for structural application represents an opportunity for decreasing the consumption of primary raw materials and waste generation, thus increasing global sustainability. However, this potential is nowadays not fully exploited due to standards limitations and concerns from the construction industry about the negative effect of the recycled sand in the fresh and hardened concrete performance. Thus, most of the recycled sand produced is only reused as roadbed or dumped in the landfill, whereas the recycled coarse aggregate is commonly downcycled when used for lower‐grade applications. This paper presents an overview of the quality properties of recycled materials obtained through advanced recycling technologies designed to separate high‐quality sand and coarse aggregates from hardened cement paste in demolished concrete. The study focuses on evaluating the selective separation technologies implemented in various industrial pilots and examining how the properties of recycled sands and aggregates compare to those of virgin materials of good quality, and their impact on performance. The test results indicate that there is a strong link between recycled sand quality and its effect on workability and strength development of cement‐based materials. This study also identifies critical aggregate parameters based on which one can come up with realistic replacement levels of natural with recycled sands and aggregate without compromising performance in fresh and hardened state. Our intention is to provide sufficient evidence to specifiers and designers that good quality recycled sands can be used in larger amounts in structural concrete. [ABSTRACT FROM AUTHOR]

The current state of separation technology often neglects the multidimensional nature of real particle systems, which are distributed not only in terms of size, but also in terms of other properties, such as surface charge. Therefore, the aim of this study is to experimentally investigate the applicability of magnetic seeded filtration as a multidimensional separation process. Magnetic seed particles are added to a multisubstance suspension, and a selective heteroagglomeration with the nonmagnetic target particles is induced, allowing for an easy subsequent magnetic separation. The results show that high separation efficiencies can be achieved and that the parameters pH and ionic strength govern the agglomeration process. Selective separation based on surface charge was observed, but undesirable heteroagglomeration processes between the target particles lead to a loss of selectivity. Particle size was clearly identified as a second relevant separation feature, and its partially opposite influence on collision frequency and collision efficiency was discussed. Finally, experimental data of multidimensional separation are presented, in which a size-distributed two-substance suspension is separated into defined size and material fractions in a single process step. This study highlights the need for multidimensional evaluation in general and the potential of magnetic seeded filtration as a promising separation technique. [ABSTRACT FROM AUTHOR]

High‐performance membranes are critical to membrane separation technology. In recent years, 2D covalent organic frameworks (2D COFs) have attracted extensive attention in the field of membrane separation due to their high porosity, ordered channels, and fine‐tuned pore sizes, which are considered as excellent candidate to solve the trade‐off between membrane selectivity and permeability. Herein, two kinds of ionic 2D COFs with different charge properties (termed as iCOFs) are integrated into polyacrylonitrile (PAN) substrates to form two composite membranes (PAN@iCOFs) with excellent selective perfluoroalkyl substances (PFASs) separation performance with high solvent permeability and good mechanical properties. The as‐prepared PAN@iCOFs composite membranes can selectively reject more than 99.0% of positively and negatively charged PFASs in wastewater while maintaining good stability and recyclability. [ABSTRACT FROM AUTHOR]

In recent years, the environmental contamination and ecological poisons of antibiotics have possessed great challenges for human health. Versatile methods have been developed in enhanced demand for high-efficiency selective removal of tetracycline (TET), in which molecularly imprinted composite membranes (MICMs) have gained wide attention for selective separation of TET due to their preferable selective recognition and separation performance. Herein, we described a simple two-step method for developing the MICMs by using TET as a template molecule, acrylamide (AM) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker, and azo-bis-isobutryronitrile (AIBN) as an initiator. Based on ample rebinding sites and strong affinity force, the as-prepared MICMs possessed high rebinding capacity (20.15 mg/g) for adsorbing TET. The superior relative selectivity coefficients could also be achieved, which facilitated for TET adsorbed and separated. These results might be due to the design of tailor-made recognition sites for binding TET in the final application. The as-obtained MICMs showed potential applications for selective recognition and separation of TET from environmental contamination. [ABSTRACT FROM AUTHOR]

[Display omitted] This study presents an efficient amine infused hydrogels-based CO 2 separation technology from H 2 /CO 2 and N 2 /CO 2 gas mixtures. The amine-infused hydrogels (AIHs) prepared by mixing aqueous amine solution with dried hydrogel particles were exposed to the gas mixtures in static condition, then the absorption capacity of AIHs along with the initial uptake rate were obtained from the experimental data. Although the concentration of amines was less than 30 wt% for aqueous solutions, it was increased up to 45 wt% for AIHs and the absorption capacity increased from 0.4630 to 0.5046 mol CO 2 /mol amine for N 2 /CO 2 gas mixture. By varying the types of amines, the highest absorption capacity was obtained with the 45 wt% monoethanolamine AIHs (MEA-AIHs), 0.505 mol CO 2 /mol amine, as well as the initial uptake rate of 0.513 mmol CO 2 /min. Diethanolamine AIHs (DEA-AIHs) showed good absorption capacity close to the MEA-AIHs, but the initial uptake rate was low. Compared to those DEA-AIHs, MDEA-AIHs showed less absorption capacity, but higher initial uptake rate. The addition of piperazine (PZ) into the MDEA-AIHs did not improve the CO 2 absorption performance, but its positive effect was confirmed for the aqueous solution. Moreover, the presence of NO in gas mixture proved to degrade the performance of AIHs with up to 26.7 % reduction in absorption. When applying AIHs for H 2 /CO 2 gas mixtures, both the absorption capacity and initial uptake rate were increased significantly, possibly due to high CO 2 concentration and high partial pressure. MEA-AIHs showed higher initial uptake rate, but MDEA-AIHs showed better absorption capacity. The obtained results in this work suggest that AIHs can be applicable for post-combustion capture as well as for CO 2 capture for blue hydrogen production. [ABSTRACT FROM AUTHOR]

Previously, we investigated imprinted silica films templated by cellulose nanocrystals for the selective adsorption of rare earth ions from acidic systems, but the cost of organosilane limits the application of silica film adsorbents. Considering the cost and outstanding properties of cellulose, converting this renewable biological resource into an adsorbent material is a vital step towards sustainable development. One-step fabrication of imprinted mesoporous cellulose nanocrystals films (IMCFs) was implemented via ionic imprinting technology and they were applied to efficiently and selectively separate neodymium ions [Nd(III)]. Transmission photographs clearly demonstrated there is a highly ordered mesoporous structure after removal of silicon source. Nitrogen adsorption measurements showed two obtained materials possess high specific surface area, providing a good premise for efficient separation. When employed as absorbents, the maximum adsorption capacity of IMCFs is almost three folds than that of NIMCFs, reaching 18.22 mg g−1. The distribution coefficient of IMCFs for Nd(III) reached 435.46 mL g−1, much higher than other interfering ions. Repeatability tests showed IMCFs retained 81.55% of initial adsorption capacity after five adsorption cycles. In summary, this work presents a new avenue to construct imprinted mesoporous cellulose nanocrystals films for separation of rare earth ions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel method was proposed to extract REEs from rare-earth concentrate. • REEs were selectively enriched to single rare earth oxide fluoride at 1473–1773 K. • Selective separation of rare earth oxide fluoride was conducted in super gravity. • High-purity Re-rich phase with high ReO content was attained and characterized. Abstract The Bayan Obo rare-earth concentrate was obtained through mineral processing and massively disposed at the tailing dams. For efficient extraction of the rare earth elements (REEs) from the rare-earth concentrate, a novel approach was proposed to selectively enrich and separate REEs as rare earth oxide fluoride ([Ce,La,Pr,Nd]OF) phase under super gravity. Firstly, the mineral reconstruction behavior of the rare-earth concentrate revealed that REEs were selectively enriched into the rare earth oxide fluoride phase with the temperature's rising to 1473 K–1773 K under a reductive atmosphere. Subsequently, selective separation of the rare earth oxide fluoride phase was conducted under super gravity at the enriching temperature range, where the REEs were enriched as the single Re-rich phase while other minerals formed the molten slag. Accordingly, high-purity rare earth oxide fluoride phase with a high ∑ReO content of 90.35 wt.% was efficiently separated from the rare-earth concentrate under super gravity at 1773 K with G = 1000 for 10 min, which was accurately characterized for the first time to supplement some lacking data for the Re-rich phase. In addition, this manuscript provided a novel physical separation method for mineral processing. [ABSTRACT FROM AUTHOR]

In view of the difficulties in separating similar metals from acidic wastewater, a new process is proposed to selectively separate metals by controlling potential. In this study, the effects of solution potential on precipitation ratio and separation efficiency were investigated. The potential was controlled by adding sodium sulfide or xanthate and was monitored by an MT320-SpH instrument with a Pt electrode and a calomel electrode. E -pH diagrams of Me-S-H 2 O system were plotted through thermodynamic calculations. The results revealed that with the drop of solution potential, the metal precipitation ratios increased. Cu 2+ , Co 2+ , and Zn 2+ can be selectively separated and completely precipitated under controlling potential at 330 mV, 125 mV and 30 mV, respectively. Mn 2+ could be recovered by carbonate precipitation from the residual solution after Zn removal. The precipitation ratios of Cu 2+ , Co 2+ , Zn 2+ , and Mn 2+ were as high as 99%. [ABSTRACT FROM AUTHOR]

Abstract: In this study, a highly sensitive and selective sample pretreatment procedure using molecularly imprinted silica nanoparticles was developed for the extraction and determination of quercetin in red wine samples coupled with high‐performance liquid chromatography with ultraviolet detection. The imprinted silica nanoparticles were prepared in the presence of N‐acryoyl‐ l‐aspartic acid (functional monomer), quercetin (template), azobisisobutyronitrile (initiator) and methylene bisacrylamide (cross‐linker) and methanol/water (porogen) via surface‐initiated reversible addition‐fragmentation chain transfer polymerization. Surface characterization was performed and several imprinting parameters were investigated, and the results indicated that adsorption of quercetin on the imprinted silica nanoparticles followed a pseudo‐first‐order adsorption isotherm with a maximum adsorption capacity at 26.4 mg/g within 60 min. The imprinted silica nanoparticles also showed satisfactory selectivity towards quercetin as compared with its structural analogues. Moreover, the imprinted nanoparticles preserved their recognition ability even after five adsorption–desorption cycles. Meanwhile, the nanoparticles were successfully applied to selective extraction of quercetin from red wine with a high recovery (99.7–100.4%). The limit of detection was calculated to be 0.058 μg/mL with a correlation coefficient 0.9996 in the range of 0.2–50 μg/mL. As a result, the developed selective extraction method using molecular imprinting technology simplifies the sample pretreatment procedure before determination of quercetin in real samples. [ABSTRACT FROM AUTHOR]

Abstract: Magnetic molecularly imprinted nanoparticles were prepared through surface‐initiated reversible addition fragmentation chain transfer polymerization by using metronidazole as a template. The molecularly imprinted magnetic nanoparticles were characterized by attenuated total reflection Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, transmission electron microscopy, X‐ray diffraction, and vibrating sample magnetometry. The adsorption characteristics were also investigated and the kinetics of the adsorption of metronidazole on the imprinted nanoparticles were described by the second‐order kinetic model with the short equilibrium adsorption time (30 min). The adsorption isotherm was well matched with the Langmuir isotherm in which the maximum adsorption capacity was calculated to be 40.1 mg/g. Furthermore, the imprinted magnetic nanoparticles showed good selectivity as well as reusability even after six adsorption–desorption cycles. The imprinted magnetic nanoparticles were used as a sorbent for the selective separation of metronidazole from human serum. The recoveries of metronidazole from human serum changed between 97.5 and 99.8% and showed similar sensitivity as an enzyme‐linked immunoassay method. Therefore, the molecularly imprinted magnetic nanoparticles might have potential application for the selective and reliable separation of metronidazole from biological fluids in clinical applications. [ABSTRACT FROM AUTHOR]

Microalgae represent the most promising new source of biomass for the world’s growing demands. However, the biomass productivity and quality is significantly decreased by the presence of bacteria or other invading microalgae species in the cultures. We therefore report a low-cost spiral-microchannel that can effectively separate and purify Tetraselmis suecica (lipid-rich microalgae) cultures from Phaeodactylum tricornutum (invasive diatom). Fluorescent polystyrene-microbeads of 6 μm and 10 μm diameters were first used as surrogate particles to optimize the microchannel design by mimicking the microalgae cell behaviour. Using the optimum flowrate, up to 95% of the P. tricornutum cells were separated from the culture without affecting the cell viability. This study shows, for the first time, the potential of inertial microfluidics to sort microalgae species with minimal size difference. Additionally, this approach can also be applied as a pre-sorting technique for water quality analysis. [ABSTRACT FROM AUTHOR]

Selective separation of mono- and multi-valent ions has important applications in water reuse, desalination, and salt production. Innovative monovalent permselective cation-exchange membrane CR671 was developed by modifying the normal grade membrane CR67 with polyethyleneimine coating. Bench- and pilot-scale electrodialysis experiments were conducted at a brackish groundwater desalination facility to investigate desalination performance and ion selectivity using the CR671 and CR67 under different operating conditions. Both normal grade (CR67 and AR204) and selective (CR671 and AR112B) membranes achieved same desalting efficiency. Na-selectivity in terms of relative transport number using sodium as the standard ion was affected significantly by current density and linear velocity for the normal grade membranes while the selective membranes exhibited stable good Na-selectivity. The Na-selectivity of the CR671 was demonstrated up to 9 and 5 times better than the CR67 during pilot- and bench-scale electrodialysis, respectively. Hydraulic retention time and electrodialysis stack staging had minor impact on Na-selectivity at high current density. With the same hydraulic conditions, overall desalination behavior and ion selectivity were highly comparable between bench- and pilot-scale electrodialysis. It infers that bench-scale testing results can be used to simulate and project desalination performance and ion selectivity of pilot- and potentially full-scale electrodialysis applications. [ABSTRACT FROM AUTHOR]

A novel pyridine based polymer (PAPY) bearing typical bis(2-pyridylmethyl)amine and additional amino groups was newly prepared with much lower cost (46.5 USD/kg) than commercial resins with bis(2-pyridylmethyl)amine functional groups such as M4195 and TP220 (134.6 USD/kg). PAPY is a weakly basic resin with polymethacrylate–divinylbenzene matrix. Due to the relatively more hydrophilic matrix and more modified functional groups, PAPY owned the highest selectivity for nickel from high-concentration cobalt solutions even under highly acidic condition (pH ∼ 2). The highest separation factor of 129.2 ( C 0, Ni / C 0, Co  = 1:5000) could be achieved for Ni(II) versus Co(II) with PAPY, which is 100.1%, 53.6% more than those with M4195 and TP220, respectively. Because of the stronger deprotonation ability and the higher chelation binding energy, Ni(II) could form the more stable structure of two five-member rings in solid phase than Co(II). This may be the predominant mechanisms for the highly efficient separation between Ni(II) and Co(II). More attractively, Co(II) could speed up the initial adsorption rate of Ni(II) by 16.30% due to the affinity of functional groups and the electrostatic repulsion of Co(II). Far more high-purity cobalt (>99.99%) could be obtained by PAPY in the dynamic tests. With good regeneration and reusability, PAPY possesses great potential in the green and economical preparation of high-purity cobalt. [ABSTRACT FROM AUTHOR]

In this work, the extraction selectivity on Cu(II) against other impurity metal ions is greatly improved with 2-ethylhexyl 4-pyridinecarboxylate ester (L II ) as a synergist where dinonylnaphthalene sulfonic acid (HDNNS) was used as an extractant. To illuminate the synergistic extraction mechanism, a model complex of Cu(II) with nahpthalene-2-sulfonic acid (HNS) and n-hexyl 4-pyridinecarboxylate ester (L I ) was synthesized and characterized by single crystal X-ray diffraction, elemental analysis, thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and electrospray ionization mass spectrometry (ESI-MS), respectively. The crystal structure analysis indicates that the molecular structure of the Cu(II) model complex is determined as [Cu(NS) 2 (L I ) 2 (H 2 O) 4 ], where Cu(II) is directly coordinated with two deprotonated HNS, two monodentate L I and two water molecules to form a twisted octahedral configuration. Furthermore, in order to provide parallels to actual solvent extraction, the extracted Cu(II) complex in the non-polar organic phase was also prepared and studied using FT-IR and ESI-MS. Compared with the spectra of both the Cu(II) model complex and the extracted Cu(II) complex, it could be inferred that the extracted Cu(II) complex probably has an identical coordination configuration with the Cu(II) model complex, and the inner coordination sphere of Cu(II) might be occupied with N atoms from pyridine ring in two L II molecules, O atoms from two water molecules and O atoms of two deprotonated HDNNS molecules, respectively. The microscopic mechanism on the selective extraction of Cu(II) was proposed. [ABSTRACT FROM AUTHOR]

It is always difficult to separate scandium from yttrium and lanthanides due to their similar physicochemical properties. In this work, a selective separation strategy for Sc (III) from yttrium and lanthanides in aqueous solution was developed by using ionic liquids 1-alkylcarboxylic acid-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([(CH 2 ) n COOHmin][Tf 2 N]) (n = 3, 5, 7) as extractants and 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C n mim][Tf 2 N]) (n = 4, 6, 8, 10) ionic liquids as diluents. The extraction parameters such as phase valume ratio, equilibrium time, pH value of the aqueous phase, alkyl chain length of the extractants and diluents, and system temperature were investigated systematically. It was shown that the extraction efficiency of Sc (III) increased with the increase of aqueous phase pH value, and was as high as 99.5% at pH 4.2. Sc (III) could be extracted selectively from yttrium and lanthanides by simple tuning of pH value of the aqueous phase, and the separation factor was 10 3 . After the extraction, stripping of Sc (III) from the ionic liquids was attempted by using dilute aqueous HNO 3 . In addition, an ion exchange mechanism of the proton of extractants and the cation of the diluents was proposed from a series of control experiments. Since both the proton of the extractants and cation of the diluents participated in the extraction process, amount of the ionic liquids transferred to water phase can be greatly reduced compared with the cation exchange based metal extraction using only ionic liquid extractants. [ABSTRACT FROM AUTHOR]

Separation of glyoxylic acid from unpurified multicomponent technological mixtures, resulting in the process of direct oxidation of glyoxal, and preparation of sodium glyoxylate are developed. The mixtures are treated with an optimal amount of CaCO3,which has to be prespecified by acidic–basic titration of the technological mixtures. Both separation of glyoxylic acid and preparation of sodium glyoxylate take place owing to ionic exchange reactions: calcium glyoxylate is easily converted into glyoxylic acid by action of oxalic acid. Reaction with Na2CO3leads to the formation of sodium glyoxylate. [ABSTRACT FROM AUTHOR]

Aluminum is an impure element in acidic solutions obtained from gallium sources. Therefore, the selective separation of gallium from aluminum, using cupferron as a ligand (chelating agent) and sodium dodecyl sulfate as an anionic collector was investigated by flotation. The effect of the solution pH, the molar ratio of cupferron to gallium, the collector concentration, the impeller speed, the conditioning time and the flotation time on the selective separation of Ga(III) from Al(III) were studied. The results indicate that the chelating agent cupferron, efficiently separated gallium from aluminum, owing to the higher chelating strength of the interaction between Ga(III) and cupferron. The Ga(III)-cupferron complexes, formed in the presence and absence of SDS, were spectroscopically confirmed and characterized by Fourier transform infrared (FTIR), UV–visible spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX). The bonding of cupferron with Ga(III) was considered to be as a bidentate ligand, and gallium formed 1:1.5 complexes with cupferron in aqueous solution. The separation mechanism of flotation was proposed owing to the formation of a physical interaction between the Ga(III)-cupferron complex and SDS. [ABSTRACT FROM AUTHOR]

For highly sensitive determination of trace-level compounds in environmental, biological, and food samples, a selective separation and concentration are usually required with a removal of contaminants before quantitative detection by spectroscopic detection techniques, such as mass spectrometry. In the last few decades, molecularly imprinted adsorbents have widely contributed to the separation and concentration in liquid-phase separations. In this study, the latest preparation procedures, such as the use of surface modifications, inorganic substrates, and monolithic materials, in the molecular imprinting techniques are summarized. Recent achievements of practical quantitative determination in a variety of fields by new methodological protocols with molecular imprinting are also reported. [ABSTRACT FROM AUTHOR]

Novel molecularly imprinted polystyrene nanospheres composite alumina membranes (MIPS/CAM) were prepared by modifying the alumina membranes with MIPS nanospheres via microemulsion polymerization method. The as-prepared MIPS/CAM were characterized by Raman spectra, SEM, and UV–vis techniques. The particle sizes of MIPS nanospheres ranging from 25.3 to 112.5 nm over MIPS/CAM could be tuned by controlling the surfactant amount and the adding rate of oil phase into water phase. The flux study showed that the MIPS/CAM possessed good porosity. The selective recognition of phenol over MIPS/CAM was much higher than that over the NIPS/CAM. The phenol adsorption amount and the selectivity coefficients of MIPS/CAM to phenol ( α ′ phenol/SA ) increased with decreasing the particle sizes of MIPS nanospheres. The MIPS/CAM showed good recovery performance of phenol from industrial SA effluent. [ABSTRACT FROM AUTHOR]

Zinc is one of the impure elements in acidic solutions obtained from gallium sources; therefore, flotation studies were performed to investigate the removal of Ga(III) from Zn(II) using sodium dodecyl sulfate (SDS) as an anionic surface-active agent. In this study, the effect of different pH values on the percentage removal of Ga(III) and Zn(II) was studied. It was observed that the distribution of hydrolysis species and change in pH, had a significant effect upon the separation of Ga(III) from Zn(II). Also, the selective separation of Ga(III) was dependent on the recovery of water from the froth. The results showed that the optimal selective separation could be obtained at low pH values when the species of Ga 3+ was predominant and the precipitation of Ga(III) was at a minimum. The effect of pH on the characterization of the sublate (insoluble complexes formed in scum layer) and the complexation of SDS with hydrolysis species were studied by scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. In order to obtain more information about the mechanism of selective separation, the interaction of Ga(III) and Zn(II) with SDS was investigated using turbidity technique. [ABSTRACT FROM AUTHOR]

In this paper, selective separation of the isomeric compounds geraniol and nerol, based on the preferential affinity of β-cyclodextrin (β-CD) for geraniol was investigated. To demonstrate the potential application of β-CD for separation of geraiol from nerol, the structure of the inclusion complexes was characterized with various physico-chemical techniques. The selective noncovalent binding property of β-CD was confirmed by quantum-chemical calculations. For the mixture, which contains 50 wt% of geraniol and nerol, respectively, 96% of geraniol in complex can be obtained, and the similar separation efficiency was found after use for three times. [ABSTRACT FROM AUTHOR]

Magnetic nanocomposites have been well recognized as promising candidates for enzyme immobilization, DNA extraction, targeted drug delivery, and removal of various metal ions. In this paper, dedoped Fe 3 O 4 /PPy nanocomposite has been obtained by simple ammonia-washing of the newly-formed Fe 3 O 4 nanoferrofluid/PPy derived from in situ polymerization approach. The magnetic nanocomposite is characterized with XRD, FT-IR, TEM, BET, zeta potential, and magnetometry techniques, and further tested in the role of separating Ag(I) from mixed metal-ion solutions containing Ag(I), Mg(II), Cu(II), Zn(II), As(III), and Pb(II). The adsorption of Ag(I) upon dedoped Fe 3 O 4 /PPy is an endothermic and spontaneous chemisorption process, ensuring rapid separation of Ag(I) from aqueous solution. The maximum adsorption capacity of Ag(I) upon dedoped Fe 3 O 4 /PPy is 143.3 mg g −1 . The total adsorption process preferably follows the Langmuir model and the pseudo-second order kinetics. Mg(II), Cu(II), Zn(II), and As(III) have minor effects whereas Pb(II) has a relatively remarkable effect on selective separation of Ag(I) from solutions. The magnetic nanocomposite is featured with superparamagnetism, a multicore–shell structure, a soft-base surface, excellent reusability, and a high anti-interfering ability for selective separation of Ag(I) from multiionic solutions, presenting a promising candidate for practical application in selective separation of Ag(I) from silver-containing emissions. [ABSTRACT FROM AUTHOR]

Non-ferrous smelting dust, especially lead-smelting dust (LSD), contains percent levels of indium and thus constitutes a novel indium resource. The main difficulty in recovering indium from LSD is the coexisting presence of lead and zinc. In this study, a unique indium separation process was designed, combining techniques that involve washing with a chelant, leaching with acid and precipitation as hydroxide. The majority of the Pb in the LSD was selectively separated during chelant-assisted washing with ethylenediaminedisuccinate (EDDS), while the residual Pb was diminished through an acid leaching treatment with a mixed solution of sulfuric acid and hydrochloric acid. The chelant washing step also ensures a decrease in the raw LSD weight at a ratio of approximately 82% due to the removal of lead and counterions such as sulfate, and the washing step also minimizes the consumption of corrosive acids in the subsequent step. Selective indium separation from LSD is further complicated by the similarity of the behavior of zinc during the acid leaching step. Therefore, hydroxide precipitation at pH 5 has been introduced as the final step, ensuring the maintenance of zinc as a soluble species in the supernatant and the selective separation of indium (∼88%) as a hydroxide precipitate. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate a new kind of surface imprinted smart polymer by using methacrylic acid (MAA) as function monomer, attapulgite as the support material, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, and 2, 2’-azobisisobutyronitrile (AIBN) as initiator to prepare Cu(II)-imprinted microgels. The results showed that the prepared imprinted microgels have a high affinity for Cu2+over Ca2+and Mg2+, and the adsorption equilibrium data fitted Freundlich isotherm model well. In addition, Cu(II)-imprinted smart microgels had pH sensitivity to control the selection recognition property. Besides, It is suggested that the Cu(II)-imprinted microgels was a material that was efficient, low-cost, and could be reused five times with about 15% regeneration loss. [ABSTRACT FROM AUTHOR]

• A new finding and method for selective separation of different REEs was proposed. • Different REEs could be selectively enriched into various RE-phases, respectively. • High-purity RE-phases containing different REEs were separated by super gravity. • High-purity RE-phases were characterized to supplement the missing crystal information. The significant increase in global consumption of rare earth elements (REEs) has attracted more attention to the separation of REEs from complex rare-earth systems. Bayan Obo ore is the world's largest rare-earth deposit, where REEs are mainly transfered to RE-concentrate which contains various species of REEs (mainly includes lanthanide: Ce, La, Pr, and Nd). This study reported a new finding and technology for selective separation of different REEs from Bayan Obo RE-concentrate system. The basic data on phase transformation of different REEs in CaO-SiO 2 -CaF 2 -P 2 O 5 -Fe 3 O 4 -RE 2 O 3 systems were reported, and firstly found that different REEs of Ce, La, Pr and Nd could be selectively enriched into cerium oxide, lanthanum ferrate, praseodymium apatite and neodymium apatite, respectively. A novel technology of separating RE-phases via super gravity was proposed, various high-purity RE-phases containing different REEs were separated and characterized, and the crystal information missing in the current database were supplemented. [ABSTRACT FROM AUTHOR]

The development of energy-efficient processes for selective separation of p-xylene from mixtures with its isomers is of vital importance in the petrochemical industries. Current industrial practice uses BaX zeolite that has high adsorption selectivity for p-xylene. Finding para-selective structures is challenging. With state-of-the-art simulation methodologies we systematically screened a wide variety of zeolites and metal-organic frameworks (MOFs). Our investigations highlight the crucial importance of the channel dimension on the separation. MAF-X8 is particularly noteworthy because the channel dimensions and geometry allow 'commensurate stacking' which we exploit as a separation mechanism at saturation conditions. Due to a significantly improved capacity compared to BaX, the cycle times for p-xylene with MAF-X8 are found to be about a factor of 4.5 longer. This is expected to result in significant process improvements. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new metal–organic framework (ZJU-61) was synthesized. [•] ZJU-61 displays three different types of pore apertures. [•] ZJU-61 exhibited the highest C2H2/CH4 separation selectivity of 74.4. [Copyright &y& Elsevier]

Cross-linked membrane of zirconium tri-ethylene tetra-amine (ZrTETA-55) was prepared by sol-gel method using poly (vinyl alcohol) (PVA) in aqueous media for selective separation of Cu2+. Developed ZrTETA-55 hybrid membrane exhibited good thermal, mechanical, and chemical stabilities, which are essential parameters for its durability. ZrTETA-55 hybrid membrane was used as an adsorbent for selective adsorption of Cu2+, and the effect of time, temperature, pH, adsorbent dose, and adsorbate concentration were investigated. The adsorption process followed the pseudo-first and pseudo-second-order kinetic models which were also evaluated. The equilibrium adsorption obeyed the Langmuir and Freundlich isotherms. The thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were calculated. From thermodynamic data, it was found that the adsorption process was endothermic and spontaneous. The maximum adsorption of Cu2+ions was found to be ∼74% at pH 7 and indicated that the developed material could be effectively utilized for the selective separation of Cu2+in the presence of other bi-valent ions in industrial effluents. Supplemental materials are available for this article. Go to the publisher's online edition ofSeparation Science & Technologyto view the supplemental file. [ABSTRACT FROM AUTHOR]

The filtration membranes for selective separating mixture of fluids or particles are of great importance to numerous fields, ranging from pharmaceutical industries, automotive industry, and chemical engineering to individual protection. However, current membranes are difficult to simultaneously attained high separation efficiency, high flux, and easy to scale up, which have restricted their practical applications. Herein, we have prepared the neuron-like polyurethane nanofibrous materials with numerous cavities among fibers and beads. The resultant membranes exhibited underoil superhydrophobicity (163°), extremely low adhesion force (1.13 μN), and sliding angle (1.7°). The superwettability, small pore size, high porosity, and interconnected pore channel endowed the membranes with good separation performance towards water-in-oil emulsions, including high separation efficiency of 99.44%, permeation flux of 3874 L m−2 h−1, and good reusability in 15 cycles. In addition, the neuron-like PU nanofibrous membranes presented intriguing waterproof performance with water vapor transmission rate of 10592.3 g m−2 d−1. Furthermore, the neuron-like PU nanofibrous membranes exhibited superior separation performance towards both sodium chloride and oily aerosol particles with filtration efficiency >99.99%, pressure drop of ∼90 Pa, and quality factor value > 0.1. The good selective separation performance of prepared PU nanofibrous membranes paves a way for fabricating filters for the separation of air/particles, oil/particles, emulsions, and water/moisture in different fields. [Display omitted] • The robust neuron-like PU nanofibrous membranes were fabricated by electrospinning • The PU nanofibrous membranes exhibited superwettability to water and oil. • The membranes exhibited intriguing separation performance towards W/O emulsions. • The membrane presented good waterproof and air/oily aerosols filtration performance. [ABSTRACT FROM AUTHOR]

With the continuous improvement of technological level, the potential of rare earth elements (REEs) called "industrial gold" in various fields has been continuously explored, and some rare earth elements are regarded as very valuable additives in the high-tech field. With the rapid development of the rare earth industry in recent years, the demand for REEs has continued to rise. Because neighboring rare earth elements have extremely similar physical and chemical properties, in industrial applications, the purity of rare earth elements has high requirements, so the separation between rare earth elements is particularly important. Over time, people have developed a variety of techniques for the separation and recovery of rare earth elements, commonly used including chemical precipitation, ion exchange, solvent extraction, membrane separation, and adsorption, etc. At present, there are few reports on the comprehensive progress of all separation and purification technologies for a single rare earth element. This article mainly summarizes the latest developments in the separation of rare earth elements, evaluates the advantages and disadvantages of various process technologies, and prospects the development prospects of rare earth element separation technologies. [Display omitted] • Latest developments in separation technologies of single rare earth elements were reviewed. • Different technologies commonly used in rare earth separation at present were briefly evaluated. • Adsorption method in the separation of rare earth elements was mainly introduced. • Challenges faced by the current rare earth separation technologies were also put forwarded. [ABSTRACT FROM AUTHOR]

Abstract: Organic–inorganic hybrid cation-exchange membranes (CEMs) were chemically modified by in situ polymerization of aniline in acidic medium using FeCl3 as an oxidizing agent. The presence of polyaniline (PANI) on the surface and inside membrane matrix was confirmed from PANI coating density and scanning electron microscopy. Membranes were characterized in details by estimating water uptake, ion-exchange capacity, fixed ion concentration, counter-ion transport number and membrane conductivity. The values of Na+ transport number across the membranes were unchanged, whereas the values of Zn2+ and Al3+ transport number were decreased after modification with PANI. The dense nature of PANI modified membranes was evaluated through an electro-osmotic study. The selectivity of PANI modified membranes towards Na+, Zn2+ and Al3+ ions was investigated by electrodialysis using single or binary mixture of electrolyte solutions (Na+/Zn2+ and Na+/Al3+). The current and separation efficiencies of CEM and PANI modified membrane (CEM/PANI-120) for Na+, Zn2+ and Al3+ were determined at varied applied current densities and electrolyte solution feed concentrations. The obtained values of current and separation efficiencies for CEM/PANI-120 membrane suggested the suitability of PANI modified membrane in electrodialysis selective separation of Na+ from the binary mixture (Na+/Zn2+ and Na+/Al3+) in aqueous solutions. [Copyright &y& Elsevier]

The performance of continuous cross-flow micellar enhanced ultrafiltration (MEUF) is evaluated for the selective separation of nickel (Ni2+) and cobalt (Co2+) from the aqueous stream using anionic surfactant sodiumdodecyl sulfate (SDS) and the mixture of the anionic and nonionic surfactant (SDS+TritonX-100) with the addition of iminodiacetic acid (IDA) as a chelating agent. Operating parameters like operating time (upto 100 min), cross flow rate (100–175 mL/min.), pH of the feed solution (3-6), molar concentration ratio of the chelating agent to metals (C/M ratio, 0.5–2.5), and molar concentration ratio of the surfactant to metals (S/M ratio, 5–9) were studied to investigate the effectiveness of the process on selective separation. For the single surfactant system at all empirically selected parameters, 92% Ni2+in the permeate and 94% Co2+in the retentate was achieved whereas for the mixed surfactant system 93% Ni2+in permeate and 84% Co2+in retentate was achieved. Flux variation for single and mixed surfactant system was studied. Flux observed for the single surfactant system was 36 L/m2.h and for the mixed surfactant system was 31.5 L/m2.h. Flux measurement also indicates insignificant fouling of the membrane. [ABSTRACT FROM PUBLISHER]

Abstract: This work is focused on the study of the electrodeposition stage of a combined polymer-supported ultrafiltration (PSU)–electrodeposition process for the recovery and selective separation of Cu/Zn mixtures. With this aim, the electrodeposition of Cu/Zn mixtures was evaluated in the presence of ethoxylated polyethylenimine, a polymer that has exhibited good performance in PSU processes in previous studies and whose performance has been fully characterised in the literature. It was determined that at pH values equal to or less than 4, macromolecular complexes formed with both Cu and Zn are weak and electrodeposition can take place very efficiently, with the deposition of copper being strongly favoured. For values of the applied electrical charge equal or greater than 0.1 A h dm−3, the purity of the copper deposit is greater than 99% for the range of Cu/Zn molar ratios between 1 and infinity. Next, long-term experiments in continuous mode showed that the average deposition rate was close to the maximum rate achieved when operating in discontinuous mode and that the electrodeposition process does not negatively affect the performance of the polymer in the PSU processes. [Copyright &y& Elsevier]

A method for the selective separation of polychlorinated naphthalene (PCNs), hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA) in complex matrices was developed. In the present study, the type of sorbents and the volume and composition of eluting solvents were investigated in detail. Under the optimal conditions, the recoveries of PCNs, HBCDs and TBBPA in different fractions were determined with liquid/gas chromatography tandem mass spectrometry (LC or GC-MS/MS), which was nearly close to 100%. To investigate the feasibility of the developed method, it was applied to isolate target compounds from spiked soil extracts. PCNs, HBCDs and TBBPA could be subsequently eluted with hexane, hexane/dichloromethane (1:1), and hexane/dichloromethane (1:3), and the recoveries of the analysts from three fractions were satisfactory (70.9%-107%) with the exception of γ-HBCD at low levels. The results indicated that the method exhibited good performance for the selective separation of PCNs, HBCDs and TBBPA and showed great potential in sample pretreatment in terms of alleviating influence from different class of impurities to some extent. [ABSTRACT FROM AUTHOR]

Abstract: A single-step selective separation of two food additives was investigated using alcohol-salt aqueous two-phase systems (ATPS). The selective partitioning of two of the most used additives from a processed food waste material, vanillin and l-ascorbic acid, was successfully accomplished. The results obtained prove that alcohol-salt ATPS can be easily applied as cheaper processes for the selective recovery of valuable chemical products from food wastes and other sources. As a first approach, the phase diagrams of ATPS composed of different alcohol+inorganic salt+water were determined at 298 (±1)K and atmospheric pressure. The influence of methanol, ethanol, 1-propanol, and 2-propanol and K3PO4, K2HPO4 or KH2PO4/K2HPO4 in the design of the phase diagrams was addressed. After the evaluation of the phase diagrams behaviour, the influence of the phase forming constituents was assessed towards the partition coefficients and recovery percentages of vanillin and l-ascorbic acid among the coexisting phases. Both model systems and real processed food waste materials were employed. Using these ATPS as partitioning systems it is possible to recover and separate vanillin, which migrates for the alcohol-rich phase, from l-ascorbic acid, which preferentially partitions for the salt-rich phase. [Copyright &y& Elsevier]

Abstract: Special attention has been given to the separation and recovery of VII-group elements, Tc and Re, in relation to the partitioning of high-level liquid waste (HLLW) generated from the nuclear fuel reprocessing process. In this study, a tertiary amine (tri-n-octylamine, TOA), which is effective for the extraction of oxoanions, was encapsulated in Ca and H-types of alginate xerogel polymers (CaALG, HALG). The uptake behaviors of TcO4-and ReO4− (substitute of Tc) in the presence of HNO3 were examined by batch method using TOA-xerogel microcapsules (TOA-CaALG, TOA-HALG). The uptake of TcO4- in the presence of 0.1M HNO3 was readily attained within 5h, and a relatively large uptake(%) above 90% was obtained. The uptake(%) of Re(VII) for TOA-CaALG in the presence of 0.01∼0.1M HNO3 was estimated to be about 90%, while gradually decreasing with HNO3 concentration, indicating that the extraction of HNO3 with TOA became dominant in this process: R3NH+NO3 (o) + ReO4 (aq) ↔ R3NH+ReO4 (o) + NO3 (aq). The order of the uptake(%) for different oxoanions in the presence of 0.01∼5M HNO3 was Re(VII) > Zr(IV)> Se(VI) > Mo(VI) > Te(VI). The elution study of Tc(VII) revealed 95% and 99% of recovery with 5M and 7M HNO3, respectively. The chromatographic separation of Re(VII) from simulated HLLW (28 components of waste solution, SW-11E, JAEA) as well as from mixed solution was accomplished by the stepwise elution techniques using a column packed with TOA-MCs. The Re(VII) ions were effectively eluted with 5M HNO3, and a relatively large recovery(%) of 98.60% was obtained. Other elements were eluted with H2O and 2M HNO3. Thus the TOA-xerogel microcapsules are effective for the selective separation of Tc(VII) from HLLW. [Copyright &y& Elsevier]

The affinity of Chelex-100 for radium has been investigated as a function of pH and salinity compared to the Chelex-100 affinity for uranium to assess possible application of the resin for the selective separation of the two naturally occurring radionuclides from aqueous solutions. According to the experimental data the maximum chemical recovery of Chelex-100 is observed for uranium at pH 5 and for radium at pH 3 indicating a pH controlled selectivity of the resin for the two radionuclides. Moreover, the effect of salinity on the chemical recovery of radium is significant, resulting in a dramatic decrease of the former with increasing salinity. On the other hand, there is almost no effect of the salinity on the chemical recovery of uranium, indicating the higher affinity of Chelex-100 for uranium, which could be attributed to the formation of inner-sphere complexes of U(VI) with the iminoacetic moieties of the resin. The method has been successfully applied for the uranium separation from a radionuclide mixture. [ABSTRACT FROM AUTHOR]

Fullerenes, among other carbon nanostructures, are very promising as potential components for the development of nanodevices and nanomachines. One of the current hurdles in developing such devices is obtaining components/molecules of the same size in sufficient quantity. Typically, when carbon nanostructures are synthesized, a distribution of sizes is generated. Therefore, an efficient separation technique is needed. A computational model that could identify suitable separation materials would be of considerable value. Herein, we apply the AM1-FS1 method, an empirically corrected version of the AM1 Hamiltonian, to study the complexation of eight different fullerenes by four different polycyclic aromatic hydrocarbon nanorings. We find (not unexpectedly) that the diameter of the nanoring governs the expected guest; however, two different size fullerenes may adopt conformations with a common diameter, eliminating selectivity. Therefore, selective separation of fullerenes is a conformation problem, with increasing prevalence as the size of the fullerenes increase. [ABSTRACT FROM AUTHOR]

Results are reported from a study of the effect of the antimonate content of sulfides on oxidation activity, pH, and oxidation-reduction potential ( E) in bacterial oxidation. A comparison is made between the bacterial-oxidation parameters of selective arsenic and antimony concentrates and a collective sulfide concentrate. The study results show that the kinetics of bacterial oxidation of the arsenic concentrate can be improved significantly by performing flotation in accordance with a new flow scheme that extracts antimonate from gold-bearing sulfide ore as a separate concentrate. [ABSTRACT FROM AUTHOR]

Abstract: An ion imprinted membrane with a porous polyvinylidene fluoride (PVDF) support was prepared by surface ionic imprinting technology. Ion imprinted membranes possess artificial recognition sites, which are able to specifically rebind a target ion in the presence of other similar compounds. In this study, Ni(II) ion imprinted membrane (IIM) was synthesized by copolymerization of Ni(II) ion (or without it for non-imprinted membrane) and dithizone as chelating ligand in the presence of methacrylic acid (MAA), ethyleneglycol dimethacrylate (EGDMA) as monomer and cross-linker, respectively using 2,2-azobisisobutyronitrile (AIBN) as initiator. Dithizone was selected as complex agent to show the capability of using a non-special ligand for synthesis of selective ion imprinted membrane. The affecting parameter such as pH and concentration of Ni2+ ion solution on the loading capacity of membrane were investigated. To obtain the maximum adsorption efficiency of Ni, pH of the sample solution should be carefully adjusted at 8. In addition, the effect of imprinting technique on the selective recognition of Ni(II) ion towards Co(II) ions through the modified imprinted membrane was studied in the permeation experiments. The results of permeation and adsorption experiment indicated that, the Ni(II) ion imprinted membrane has the ability of specificity and recognition towards the imprinted nickel ion compared to the non-imprinted polymer membrane. The separation factor (α) of the imprinted membrane for the Ni2+ ion versus Co2+ ions was 2.6, whereas the non-imprinted and control membrane (without dithizone ligand) did not show any selectivity. [Copyright &y& Elsevier]

In this work, ionic liquids/water distribution ratios (D) of azo dyes, including 1-(phenylazo)-2-naphthol, 1-(2-pyridylazo)-2-naphthol, 4-(nitrophenylazo)resorcinol, 4-(2-pyridylazo) resorcinol, and 2-(4-dimethylaminophenylazo) benzoic acid, have been determined experimentally. It was found that the D values are highly influenced by the pH of the water phase and the type of salts added. They increase with increasing alkyl chain length on the cations of the ionic liquids, and the anionic effect follows the order [BF4]- > [PF6]-. Possible extraction mechanism and selective separation of some azo dyes are also investigated. The results suggest that ionic liquids have potential applications in the removal and selective separation of azo dyes from water. [ABSTRACT FROM AUTHOR]

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A composite cation exchange material acetonitrile stannic(IV) selenite was prepared under different experimental conditions. The ion exchange capacity of the material was improved from 0.75 to 1.83 meq g-1 in comparison to its inorganic counterpart, stannic selenite. The material was characterized on the basis of X-ray, TGA, FTIR, and SEM studies. Ion-exchange capacity, pH titration, elution behavior, and distribution studies were also carried out to determine the preliminary ion-exchange properties of the material. Furthermore, it was investigated that this ion exchange material has a good reusability after 8 times regeneration. The sorption behavior of metal ions was studied in nonionic surfactants namely triton x-100 and tween. On the basis of distribution coefficient studies, several binary separations of metal ions viz- Pb2+-Th4+, Ni2+-Th4+, Ni2+-Zn2+, Cu2+-Ce4+, Al3+-Bi3+, and Al3+Zn2+ was achieved on the packed column of this ion exchange material. The practical applicability of this cation-exchanger was demonstrated in the separation of Th4+ from a synthetic mixture of Th4+, Ca2+, Sr2+, Ni2+, and Mg2+ as well as Cu2+ and Zn2+ from a brass alloy sample. Thus, all the studies suggest that acetonitrile stannic(IV) selenite has excellent potential for the removal of metal ionic pollutant species from aqueous media effectively. [ABSTRACT FROM AUTHOR]

surface-imprinted mesoporous sorbent for Pb(II) ion was synthesized by the post-synthesis method. The material was characterized by transmission electron microscopy and nitrogen adsorption-desorption isotherms. The adsorption by the material was studied by batch experiments with respect to effects of pH value, contact time, kinetics, and adsorption isotherms. Both the pseudo-second-order kinetic model and the Langmuir model fit the experimental data well. Compared to other imprints for Pb(II), to the traditional sorbents and to the non-imprinted polymer, the new sorbent displays fast kinetics and higher selectivity. Pb(II) ion can be desorbed from the imprint with 2 M hydrochloric acid with high efficiency. The sorbent was applied to the selective separation and determination of Pb(II) in water and sediment samples with satisfactory results. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Selective separation of Cu(II) ions from aqueous solution was accomplished with a new type of ion-imprinted silica nanotube membrane. A study on its capability for adsorption and selective recognition showed that best selectivity coefficient over Zn(II) ion was over 150, which is much higher than those of control silica nanotube membranes. The largest relative selectivity coefficient over Zn(II) was >200. The new membrane also possess a fast kinetics for the removal of Cu(II) from aqueous solution, an equilibrium period of <30 min, and suitability for repeated use. Hence, the new membrane acts as an effective material for highly selective preconcentration and separation of Cu(II) ion. [ABSTRACT FROM AUTHOR]

Abstract: Selective fine particle separation is a key unit operation in the mineral and related industries. In flotation, the capture of fine particles by bubbles is inefficient due to their low mass and momentum, which result in low particle–bubble collision efficiency. We demonstrate that it is possible to selectively separate a mixture of very fine hydrophobic graphite and hydrophilic quartz particles by direct contact with an air–water interface without a particle–bubble collision step involved. We demonstrate that it is possible to scale-up the process from a simple batch to a continuous process. Good selective separation of graphite from quartz gangue could be obtained under continuous conditions. [Copyright &y& Elsevier]

Abstract: Copper (II) ion-imprinted porous polymethacrylate micro-particles were prepared. Two functional monomers, methacrylic acid and vinyl pyridine, formed a complex with the template copper ion through ionic interactions. The self-assembled copper/monomer complex was polymerized in the presence of an ethylene glycol dimethacrylate cross-linker by a suspension method. After the imprinting sites were provided through removal of the template, the micro-porous particles, of approximate size 200μm, were obtained for batch and column separation applications. The chemical structure and morphology of the Cu(II)-imprinted micro-porous particles were analyzed using FTIR, SEM, and BET. The adsorption capacity and adsorption kinetics of the imprinted beads for the template Cu(II) ion were significantly affected by particle size, copper ion concentration, pH, and flow rate of the feed solution. The imprinted particles showed high selectivity for the copper ion over other metal ions such as Ni and Zn. The selectivity of the present imprinted polymers for the copper ion was at least 10 times as high as those from commercial sources. [Copyright &y& Elsevier]

Abstract: Daidzein-imprinted poly(methacrylamide-co-acrylic acid) composite membranes with different ratios of methacrylamide (MAM) versus acrylic acid (AA) were prepared via UV initiated photo-copolymerization on the commercial filter paper with ethylene glycol dimethacrylate (EGDMA) as cross-linker and mixed cellulose ester as agglutinant. Infra-red (IR) spectroscopy and scanning electron microscope (SEM) were used to visualize the surface of the membranes. Binding and recognising properties of the imprinted composite membranes to daidzein and its analogues genistein were evaluated by static adsorption experiment. It was found that the daidzein-imprinted membranes showed high selectivity to daidzein, with the highest selectivity when the composite membrane with the ratio of MAM vs AA as 4:1. The results suggested that the molecularly imprinted composite membranes were potentially useful for daidzein enrichment. [Copyright &y& Elsevier]

Abstract: Submicron-size Fe3O4@silica core/shell microspheres were prepared by sol–gel method. Through coating inert silica shell and adjusting the thickness, the dispersibility of magnetic microspheres in water was greatly improved. The resultant Fe3O4@silica microspheres with controllable saturation magnetization between 34.3emu/g and 47.3emu/g were superparamagnetic. All as-prepared magnetic composite microspheres possessed fleetly magnetic responsivity. The PAA-modified Fe3O4@silica microspheres were used for selective adsorption and separation of lysozyme, and the experimental results showed that the maximum binding capacity is about 127mg/g. After surface modification of Fe3O4@silica with polyacrylic acid (PAA) flexible chains, the binding capacity of Fe3O4@silica-g-PAA microspheres for lysozyme were 22 times as much as that of pure Fe3O4@silica microspheres at the same pH condition. [Copyright &y& Elsevier]

Abstract: Complexation–ultrafiltration process was investigated to separate selectively Hg(II) and Cd(II) from binary metal solutions by using poly (acrylic acid) sodium salt as a complexing agent. Effects of operating parameters on selective separation factors (β Cd/Hg) of the both metals have been examined in detail. Results indicated that loading rate, pH, concentration of salt added and low-molecular competitive complexing agent affect significantly β Cd/Hg value. Further, a concentration experiment was carried out according to the previous optimum parameters. Rejection coefficient of mercury is close to 1, while that of cadmium is about 0.1. The experiment was characterized by good effectiveness, and enabled the rapid linear increase of mercury concentration and very slow increase of cadmium concentration in the retentate. Then, a diafiltration technique was applied to separate further the both metals. Cadmium concentration in the retentate declines sharply with the diafiltration volume, whereas for mercury it is the contrary. [Copyright &y& Elsevier]