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In this study, the ability of the highly scalable metal-organic framework (MOF) CALF-20 to adsorb polar and non-polar gases at low pressure was investigated using grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations. The results from the simulated adsorption isotherms revealed that the highest loading was achieved for SO2 and Cl2, while the lowest loading was found for F2 molecules. The analysis of interaction energies indicated that SO2 molecules were able to form the strongest adsorbent-adsorbate interactions and had a tight molecular packing due to their polarity and angular structure. Additionally, Cl2 gas was found to be highly adsorbed due to its large van der Waals surface and strong chemical affinity in CALF-20 pores. MD simulations showed that SO2 and Cl2 had the lowest mobility inside CALF-20 pores. The values of the Henry coefficient and isosteric heat of adsorption confirmed that CALF-20 could selectively adsorb SO2 and Cl2. Based on the results, it was concluded that CALF-20 is a suitable adsorbent for SO2 and Cl2 but not for F2. This research emphasizes the importance of molecular size, geometry, and polarity in determining the suitability of a porous material as an adsorbent for specific adsorbates. [ABSTRACT FROM AUTHOR]

BACKGROUND: The presence of phenolic compounds in sunflower is well reported in the literature; however, knowledge is scarce when it comes to the composition of other secondary metabolites in this species and their by-products. This work evaluated, for the first time, the phytochemical composition of sunflower meal produced in Brazil. A combination of mixture design and central composite rotatable design 2³ models was then applied to maximize the recovery of bioactive compounds using ecologically friendly solvents and concentrating by applying activated carbon, a sustainable adsorbent. The product of this extraction-concentration was also evaluated by an untargeted metabolomic approach using ultra-performance liquid chromatography coupled to mass spectrometry. RESULTS: A diverse and abundant profile of phenolic compounds was obtained from Brazilian sunflower meal: in total, 51 natural products were tentatively identified, 35 of which for the first time in sunflower. The sorption capacity of the activated charcoal, in the optimized process conditions, was effective in the separation and concentration of minority secondary metabolites. The ecofriendly extract proved to be enriched in plumberoside, p-coumaric acid, and alkaloids. CONCLUSIONS: Investigation of the phytochemical profile of sunflower meal produced in Brazil pointed to several secondary metabolites reported for the first time in sunflower samples, including phenolic compounds, alkaloids, and terpenes. The use of activated charcoal in an alkaline medium as an adsorbent for the concentration of these phytochemicals, from an aqueous extract, generated a potentially cost-effective, ecofriendly extract, enriched in minor metabolites, indicating a possible innovative way to selectively obtain these compounds from sunflower meal. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel adsorbent with dual sulfur sites was successfully synthesized via in-situ method. • High density of sulfurs was introduced both in the ligand and in the inorganic cluster. • DUT-67-SH exhibits a large adsorption capacity and rapid kinetics for Hg(II) ion. • Strong chemical bonding interaction contributes to the effective adsorption. Highly efficient removal of mercury ion (Hg2+) from aqueous solution is a serious concern. Herein, a novel metal–organic framework (MOF) containing dual sulfur sites was successfully constructed via an in-situ method. Different with previous reports, thiophene and thiol sites were simultaneously introduced via organic linker and inorganic cluster, resulting in high-density sulfur sites. The composition and porosity of the newly synthesized DUT-67-SH (DUT, Dresden University of Technology) were systematically characterized. Based on abundant sulfur sites and strong host–guest interaction, DUT-67-SH exhibits a high adsorption capacity (370.2 mg g−1) and rapid adsorption kinetics (∼3 min for equilibrium). Excellent separation selectivity, regenerability, and applicability under wide acidic pH range were further confirmed. Mechanism analysis suggests that the chemical bonding between sulfurs and Hg2+ is the main driven force. Thus, our work demonstrates that DUT-67-SH is a potential adsorbent for Hg2+, and more importantly, provides a new insight for introducing high-density sulfur sites in MOFs. [ABSTRACT FROM AUTHOR]

Organic pollutants pose a serious threat to water environment, thus it is essential to develop high-performance adsorbent to remove them from wastewater. Herein, nitrogen-doped magnetic porous carbon (M-PLAC) with three-dimensional porous structure was synthesized from lignin to adsorb methylene blue (MB) and tetracycline (TC) in wastewater. The calculated equilibrium adsorption amount by M-PLAC for MB and TC was 645.52 and 1306.00 mg/g, respectively. The adsorption of MB and TC on M-PLAC conformed to the pseudo-second-order kinetic model. The removal of MB by M-PLAC showed fast and efficient characteristics and exhibited high selectivity for TC in a binary system. In addition, M-PLAC was suitable for a variety of complex water environments and had good regeneration performance, demonstrating potential advantages in practical wastewater treatment. The organic pollutant adsorption by M-PLAC was attributed to electrostatic interaction, hole filling effect, hydrogen bonding, and the π-π interaction. [ABSTRACT FROM AUTHOR]

The solvothermal reactions of CoCl2 ⋅ 6H2O, 3,5‐pyridinedicarboxylic acid (H2L) and isonicotinic acid (HL1)/3‐amino isonicotinic acid (HL2)/3‐chloro isonicotinic acid (HL3) successfully led to three tfz‐d topological pillar‐layer [Co4(μ‐F)2(COO)6(NC5H4)4] cluster‐based MOFs, namely, [Co4(μ‐F)2(L)2(L1)2 ⋅ 2DMA] ⋅ DMA ⋅ 2H2O (SNNU‐Bai76, SNNU‐Bai=Shaanxi Normal University Bai's group), [Co4(μ‐F)2(L)2(L2)2 ⋅ 2H2O] ⋅ 2DMA ⋅ 2H2O (SNNU‐Bai77) and [Co4(μ‐F)2(L)2(L3)2 ⋅ 2H2O] ⋅ 2DMF ⋅ 2H2O (SNNU‐Bai78). With the 2D pore channels in SNNU‐Bai76 and SNNU‐Bai77 being tuned to the 1D pore channel in SNNU‐Bai78, C3H8 and C2H6 adsorption uptakes are apparently improved and the IAST selectivities of C3H8/CH4 and C2H6/CH4 almost remain, which indicate that SNNU‐Bai78 may be one potential separation material for the pipeline natural gas purification. These were further confirmed by the breakthrough experiments for the simulated pipeline natural gas (C3H8/C2H6/CH4 : 5/10/85 gas mixture) of three isostructural MOFs. Furthermore, GCMC simulations revealed that due to one of the pore channels blocked by Cl atoms in a couple of 3‐chloro isonicotinic acid with the changed conformation as the pillar, the pore wall of the formed 1D pore channel in SNNU‐Bai78 may interact with the adsorbed C3H8 or C2H6 molecule more strongly, for which more atoms of framework at the new adsorption site will interact with the adsorbed gas molecule by more intermolecular interactions. This was also evidenced by the increased binding energies, being consistent with the tuning of adsorption enthalpies for C3H8 and C2H6 gas molecules, and the reduced C3H8 and C2H6 gas diffusion coefficients in SNNU‐Bai78. Very interestingly, this work is the first example of finely tuning the pore connectivity of MOFs toward strengthened host–guest interactions for the gas adsorption and separation. [ABSTRACT FROM AUTHOR]

[Display omitted] • N -doped carbon scaffold as adsorbent matrix with highly exposed N adsorption sites. • Impregnation method offsets N loss due to annealing and magnetizes the adsorbent. • Imprinting modification confers adsorbent phenol selective adsorption capacity. • Adsorbent exhibits superior adsorption capacity owing to advantage balance strategy. • Pyridinic N is an essential factor in phenol adsorption. Producing a desirable adsorbent with strong affinity adsorption sites, excellent selectivity properties, and the ability to easily separate solid from liquid for the removal of phenol to a permissible level remains a great challenge in wastewater treatment. Herein, an N -doped magnetic carbon skeleton is presented as a porous adsorbent matrix. Importantly, the pore volume and specific surface area of the adsorbent matrix can be meticulously tuned by adjusting the thermal treatment condition, while dispersing and immobilizing the N fraction. This would ultimately result in an N -rich matrix structure with flexible mass transfer channel. The imprinted modification generates a large number of phenol-shaped geometrical cavities on the matrix. This helps to activate the phenol recognition "awareness" of N -active sites and greatly endows the adsorbent with selective adsorption property. Due to the advantageous balance between the hierarchical porous adsorbent matrix with uniformly distributed N -active sites and the imprinted polymer, the adsorbent has a superior adsorption capacity of 995.2 mg g−1 and selective recognition (K d = 3.92, 3.78; HQ, PTBP) towards phenol. It outperforms previously reported adsorbents. In addition, its easy magnetic separation property makes the adsorbent to have excellent reusability. The adsorbent presents a promising potential for separating pollutants from wastewater and it sheds light on the design of an efficient comprehensive adsorbent. [ABSTRACT FROM AUTHOR]

Herein, dithiocarbamate-modified biochar (BC-HDTC) was successfully synthesized with nitric acid (HNO3), thionyl chloride (SOCl2), branched PEI and carbon disulfide (CS2). The effective anchoring of amine and dithiocarbamate groups onto the surface of the biochar was proven by SEM, FTIR, XPS, N2 adsorption–desorption experiment. The batch experiments demonstrated BC-HDTC can selectively remove 98% Pb(II) within multi-metals solution when pH = 5, T = 30 °C. The impact of variations on the BC-HDTC were researched (pH, contact duration, Pb(II) original concentration).The sorption kinetics (pseudo-first-order, pseudo-second-order, intra-particle diffusion model) and isotherm modeling (Langmuir, Freundlich, and tempkin models) of Pb(II) on BC-HDTC were investigated. The adsorption process was depicted to attain equilibrium in less than 20 min and to fit the Langmuir isotherms and pseudo-2nd-order kinetics satisfactorily. The complexation of functional groups of HDTC (amine/imine and dithiocarbamate) with Pb(II) as well as the ion exchange between Na(I) and Pb(II) are the main adsorption mechanisms. Pb(II) onto BC-HDTC was endothermic and spontaneous, according to thermodynamic parameters. After 4 consecutive adsorption-desorption cycles, Pb removal efficiency of BC- HDTC remained over 90%. This work revealed the significant potential for Pb(II) contamination of BC-HDTC, a valuable and reusable adsorbent. [ABSTRACT FROM AUTHOR]

The high‐performance polymer para‐aramid (PPTA) is discovered to gel too soon during the polymerization process, resulting in poor processing performance. In this work, a homogeneous polymer solution containing heterocyclic para‐aramid (HPPTA) was successfully synthesized by introducing 2,4‐aminophenyl‐5‐aminobenzimidazole groups into the molecular chains of PPTA, and then HPPTA aerogel was prepared using a supercritical drying technique that took advantage of the HPPTA solution's excellent property of slow gelation. When the HPPTA polymer mass fraction was 1 wt%, the aerogel had the lowest density of 0.086 g cm−3 with a BET specific surface area of 376.59 m2 g−1. The HPPTA‐2 aerogel had better adsorption performance for anionic dye methyl orange, with a maximum adsorption capacity of 319.47 mol g−1; however, its adsorption capacity for cationic dye methylene blue and neutral dye dimethyl yellow was very low, at only 19.68 and 0 mol g−1, respectively. The selective adsorption ability of HPPTA aerogel made it a simple and scalable platform for removing anionic dyes from water solutions. Furthermore, the HPPTA aerogel has outstanding thermal properties for thermal insulation applications in severe environments due to the synergistic effect of the 3D porous structure inside the aerogel and the exceptional thermal stability of the HPPTA. [ABSTRACT FROM AUTHOR]

The removal of impurity gases (N2, CO2) in natural gas is critical to the efficient use of natural gas. In this work, the selective adsorption for N2 and CO2 over CH4 on MIL‐100 (M) (M=4Cr, 10Cr, 6Fe, 1In, 1Sc, 3V) is studied by density functional theory (DFT) calculations. The calculated adsorption energy of the large‐size cluster model (LC) of MIL‐100 (M) shows that the 4MIL‐100 (4Cr) is the best at the refinement of natural gas due to the lower adsorption energy of CH4 (−2.58 kJ/mol) in comparison with that of N2 (−21.49 kJ/mol) and CO2 (−23.82 kJ/mol). 1MIL‐100 (1Sc) and 1MIL‐100 (6Fe) can also achieve selective adsorption and follows the order 4MIL‐100 (4Cr)>1MIL‐100 (1Sc)>1MIL‐100 (6Fe). In the research of the selective adsorption mechanism of MIL‐100 (M) (M=4Cr, 1Sc, 6Fe), the independent gradient model (IGM) indicates that these outstanding adsorbents interact with CO2 and N2 mainly through the electrostatic attractive interaction, while the van der Walls interaction dominates in the interaction with CH4. The atomic Projected Density of State (PDOS) further confirms that CH4 contributes least to the intermolecular interaction than that of CO2 and N2. Through the scrutiny of molecular orbitals, it is found that electrons transfer from the gas molecule to the metal site in the adsorption of CO2 and N2. Not only does the type of the metallic orbitals, but also the delocalization of the involved orbitals determines the selective adsorption performance of MIL‐100. Both Cr and Sc share their dz2 ${{d}_{{z}^{2}}}$ orbitals with the gases, making 1MIL‐100 (1Sc) another potential effective separator for CH4. Additionally, the comparison of adsorption energy and PDOS shows that the introduction of ligands such as benzene impedes the electron donation from gas molecules (CO2, N2) to the metal site, indicating electron‐withdrawing ligands will further favor the adsorption. [ABSTRACT FROM AUTHOR]

Nanozymes have advantages over natural enzymes in terms of efficiency, stability, and economy. MVSM (Mixed Valence State MOF) is a nano‐oxidase with uricase‐like activity that may catalyze uric acid (UA) in the body into allantoin and H2O2 to treat gout and hyperuricemia by substituting natural uricase. However, it cannot specifically identify and choose UA. To increase the selectivity and affinity of MVSM for UA, the composite material MVSM@MIP is innovatively synthesized using a new synthetic approach termed the "two‐step synthesis method," which may prevent UA from being oxidized by MVSM during manufacture in this study. At the same time, this study also provides experimental proof of the effective creation of the material, the advantages of the "two‐step synthesis approach," and the high selectivity and affinity of MVSM@MIP for UA. Based on these findings, the suggested technique may be used to effectively catalyze uric acid in human urine with high activity. [ABSTRACT FROM AUTHOR]

A novel hydrophilic As(V) ion-imprinted cryogel (IIC) was green prepared by cryogelation in aqueous environment which was coincident with the adsorption condition and can improve the specific recognition performance. The methacrylamido propyl trimethyl ammonium chloride (MPTAC) was selected as the functional monomer and the saturated adsorption capacity of the prepared IIC and NIC were 55.0 mg/g and 29.4 mg/g, and with high imprinting factor of 1.87. Additionally, the prepared IIC showed admirable reusability and high selectivity, and the recovery was in the range 81.2–97.9% with RSD range of 1.9–4.3%, which was similar to the value obtained by hydride generation atomic absorption spectrometry. IIC can be used as solid material for colorimetric detection at the ultraviolet wavelength of 858 nm without color interference of material matrix, in the range 5–200 μg/L (R2 = 0.990) with a detection limit of 0.970 µg/L. Obviously, this synthetic strategy provides a simple, efficient, and green method for the preparation of water-compatible ion-imprinted polymers providing selective separation and detection of trace As(V) in real complex samples. [ABSTRACT FROM AUTHOR]

Five types of mesoporous silica‐based adsorbents were prepared by rationally implementing five diverse amine‐containing functional units into the mesoporous SBA‐15 structures. The prepared materials were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption−desorption isotherms and thermogravimetric analysis. Among the five adsorbents, the ethylenediamine functionalized SBA‐15, namely, AAPTMS‐SBA‐15, achieved the complete adsorption of Congo red (CR) at pH 6.0, with the maximum adsorption capacity of 4608 mg/g. The AAPTMS‐SBA‐15 material was used effectively for CR adsorption from the individual and binary dye aqueous solutions, indicating that AAPTMS‐SBA‐15 can selectively remove and separate CR from wastewater. The hydrogen bonding interactions between AAPTMS‐SBA‐15 and CR were beneficial to the high selectivity and excellent adsorption capacity of AAPTMS‐SBA‐15 toward CR. Moreover, the selective adsorption and efficient separation of CR realized the recovery and reusability of AAPTMS‐SBA‐15 and CR, which can not only avoid secondary environmental pollution, but also save economic costs. [ABSTRACT FROM AUTHOR]

Dyes are usual contaminants in aqueous solution. Some of them are carcinogenic and toxic. Hydroxyl‐carboxyl bifunctional hyper‐crosslinked polymers (HCHCP) carrying hydroxyl and carboxyl groups on their surface were fabricated for methylene blue (MB) adsorption by Friedel‐Crafts alkylation, using 3,4‐dihydroxyphenylacetic acid as a monomer. The maximum adsorption amount of MB was 751.88 mg g−1 according to the Langmuir isotherm model. The adsorption kinetics results demonstrated that the adsorption of MB followed the pseudo‐second‐order kinetic mode. In addition, the results of selective adsorption displayed that the HCHCP could separate MB from Acid Red 91 and methyl orange. Thus, HCHCP are promising adsorbents for cationic dyes. [ABSTRACT FROM AUTHOR]

Carbon micro/nanosphere-based surface molecularly imprinted adsorption material (SMIP@CS) has shown broad application prospects in the field of organic compound adsorption removal and recovery from liquid-phase environmental systems since it can meet all the separation requirements of high efficiency, deep level, identified selectivity, non-destructiveness, and recyclability. In this review, typical SMIP@CS materials applied in eco-environment field in past decade are reviewed. The general preparation methods and evaluation indices of SMIP@CS are summarized. Furthermore, by exploring the relationship between the matrix materials' pore structures and adsorption properties of SMIP@CS towards organic compounds, the adsorption mechanism of SMIP@CS is deduced and confirmed. This work provides some theoretical support and practical experience for further research on imprinting matrix screening, imprinting method designing, and adsorption performance improving.

Magnetic lignin nanoparticles (MLNs) were prepared by inducing their self-assembly through lignin regeneration in the [ N -methyl-2-pyrrolidone][C1–C4 carboxylic acid] ionic liquids ([NMP]ILs), which are low-cost protic ionic liquid. [NMP]ILs are self-assembling solvent that can enhance the adsorption capacity of MLNs to a greater degree than tetrahydrofuran or H 2 O. Additionally, the anion types of [NMP]IL greatly influence the physiochemical properties of MLNs. The MLNs prepared through self-assembly with [NMP][formate] (MLN/[NMP][For]) exhibited a higher maximum adsorption capacity (134.53 mg/g) than the [NMP]ILs of C2–C4 carboxylate anions. MLN/[NMP][For] demonstrated stable adsorption within a pH range of 6–10 or at high salt concentrations (0.01–0.5 mol/L), retaining over 80 % of its regeneration efficiency after 5 cycles. In addition, MLN/[NMP][For] selectively removed cationic dyes in mixed binary anionic–cationic dye solutions. This work demonstrated the feasibility of preparing magnetic biosorbents with good selectivity and stability though regeneration and by adjusting the anions of ionic liquids. • MLNs were prepared by self-assembly through lignin regeneration in [NMP]ILs. • The anion types of [NMP]ILs greatly influenced the adsorption properties of MLNs. • The fitted maximum adsorption capacity of MB dye reached 134.53 mg/g. • The MLN/[NMP][For] could selectively remove cationic dyes in mixed dye solutions. • The adsorption mechanism was investigated by the structural characterizations. [ABSTRACT FROM AUTHOR]

The resource of trace lead (Pb2+) from wastewater bearing intricate components is imperative for sustainable progression of the lead-acid battery industry. Herein, we fabricated a tannic acid-based covalent polymeric hydrogel (TA@PMAM) with antimicrobial properties and stability via facile Michael addition reaction. The incorporation of tannic acid (TA) through robust covalent bond leads to a stable porous 3D covalent polymer network with almost no loss of mechanical properties even after 20 compression cycles. Batch adsorption experiments of TA@PMAM revealed an extraordinary adsorption capacity of Pb2+(Qe =196.6 mg/g), achieving 87.2 % of Pb2+ adsorption within the first 5 min owing to porous structure, numerous adsorption sites and good hydrophilicity. Moreover, TA@PMAM demonstrated a strong affinity for Pb2+ in the presence of the interfere metal ions (Cu2+, Co2+, Mn2+ etc.) due to the carbonyl and phenolic hydroxyl that can specifically pair with Pb2+. Stable adsorption properties of TA@PMAM were confirmed in fixed bed column adsorption experiment using lead-acid batteries wastewater, retaining 79.56 % of initial adsorption capacity even after 10 times' reuse. Besides, TA@PMAM possesses a broad spectrum of antimicrobial properties. This study sheds novel light on the design and fabrication of adsorbent, which holds great potential for commercialization in recovering lead from battery industrial wastewater. [Display omitted] • Stable tannic acid-based covalent crosslinked 3D network is facilely fabricated. • High selectivity of Pb2+ is due to its specific pairing with carbonyl and hydroxyl. • TA@PMAM features anti-interference, reusability and broad-spectrum antimicrobial. • Calculations and cycling experiments confirm the robust attachment of TA. [ABSTRACT FROM AUTHOR]

A novel quinoline and cholesterol based organogelator G1 has been successfully synthesized and characterized. G1 could form stable organogels in ethanol, n -propanol, n -butanol, isobutanol, acetone and ethyl acetate (EA), and the concentration-dependent 1HNMR revealed that hydrogen bonding, π-π stacking and van der Walls interaction were the main driving force to form organogels via the self-assembly of G1. Furthermore, the G1 -EA gel realized selective adsorption properties for cationic dyes, such as malachite green (MG), brilliant green (BG), rhodamine B (RB) and crystal violet (CV). The results revealed that at pH = 9.90, c 0 = 18 mg·L−1, the adsorption process of G1 -EA gel for MG reached equilibrium in 7 h, and the removal rate was 99.13 %. The selective adsorption experiments of the G1 -EA gel indicated that the cationic dyes (MG and BG) were efficiently adsorbed out of the mixed dyes solutions. Also, the adsorption isotherm and the adsorption kinetics for the adsorption process were investigated, the results suggested that the Freundlich equation and the quasi-second-order kinetic model were more appropriate to describe the adsorption process. [Display omitted] • A novel quinoline and cholesterol based gelator G1 has been successfully synthesized. • The G1 -EA gel showed excellent selective adsorption properties for cationic dyes. • The selective adsorption experiments showed the cationic dyes were efficiently adsorbed in the mixed dyes solutions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Trace Hg2+ detection was achieved with a novel PVA-MPTMS-coated optical fiber sensor. • The sensitivity of the sensor can reach 17.5 nm/μM in the concentration range of 0–1000 nM. • The LOD of the sensor is 3.42 nM, which is lower than the WHO standard for drinking water. • The response time of this sensor is as rapid as 90 s. • Specific adsorption mechanism of Hg2+ based on density functional theory. A highly sensitive, selective, and well-repeatable optical fiber sensor was proposed for trace measurement of Hg2+ concentration in the water environment based on Mach-Zehnder interference. The proposed structure was prepared by splicing a piece of thin core fiber (TCF) between multimode fibers (MMF) to form MMF-TCF-MMF. A novel sensitive film 3-mercaptopropyl-trimethoxysilane (MPTMS) modified polyvinyl alcohol (PVA) has been designed and synthesized, and uniformly coated on the surface of TCF. The specific combination of Hg2+ with PVA-MPTMS sensitive film can change the effective refractive index of the coating mode, enabling the measurement of Hg2+ concentration by tracking the interference spectra. The results show that the sensitivity of the PVA-MPTMS-coated sensor can achieve 17.5 nm/μM with a detection limit of 3.42 nM in the concentration range of 0–1000 nM. The sensor represents excellent repeatability and stability and a rapid response time of roughly 90 s. Meanwhile, the proposed sensor shows a specific recognition of Hg2+ and is unaffected by many other interfering metal ions in the water, which corresponds well with the binding energy calculated by the density functional theory (DFT). The sensor for Hg2+ detection exhibits compact structure, rapid response, high selectivity and repeatability, showing promising potential applications in the field of environmental monitoring. [ABSTRACT FROM AUTHOR]

With a decline in high-grade molybdenum reserves, the development of other types of molybdenum resources have received increasing attention. Vanadium shale is a multi-metal shale and fine-grained sedimentary rock comprising small grains and various minerals. After leaching and extracting vanadium, the solution often contains a low concentration of molybdenum. However, because of the low molybdenum concentration, many processing plants treat it as an acidic wastewater, which wastes molybdenum resources and carries the risk of environmental pollution. The leaching process of vanadium shale mostly involves high-temperature and high-pressure operations, which greatly increase the content of impurity ions such as aluminium and phosphorus in the pregnant leach solution. These impurity ions increase the difficulty in separating and recovering molybdenum. In this study, the adsorption and separation of molybdenum at leach liquor of low molybdenum concentration were investigated. The effects of different factors such as: (i) pH of feed solution, (ii) adsorption time, and (iii) presence of impurity ions, aluminium and phosphorus, on the adsorption and separation of molybdenum using five different anion-exchange resins, D201, D296, D301, D314, and D301R, were investigated. The static adsorption and desorption test results showed a molybdenum adsorption capacity of 222 mg/g at pH = 1.5 by the D301 resin. The desorption efficiency using 20% NH₄OH was 96.1%. The adsorption efficiencies of aluminium and phosphorus were 1.31% and 3.10%, respectively. This is a better choice for separating molybdenum from complex solutions. The experimental results from spectra and theoretical calculations showed that the -NH group of D301 resin was combined with the O atoms of MoO 3 ·3H 2 O, Al(SO 4) 2 −, and H 2 PO 4 − by electrostatic attraction. The binding energies of these three species were − 311 kJ/mol, −231 kJ/mol, and − 62.0 kJ/mol respectively, indicating that D301 resin preferentially adsorbed MoO 3 ·3H 2 O. Based on the above results, the D301 resin can adsorb molybdenum(VI) in complex solutions under low pH conditions, and this study is expected to promote the comprehensive recovery of valuable metals from vanadium shale. • D301 resin has high adsorption capacity and selectivity for low concentration Mo in acid solution. • The main existing form of low concentration Mo in acidic solution was MoO 3 ·3H 2 O. • The N H group in D301 resin was the adsorption site and bound to Mo O in MoO 3 ·3H 2 O. • The tendency of D301 resin to preferentially adsorb Mo was higher than that of Al and P. [ABSTRACT FROM AUTHOR]

The recycling of biomass from agriculture and forestry wastes can realize high-value utilization of waste and preparation of new biosorbent material for dyeing wastewater purification. In this study, the natural luffa vine (LV) waste, with abundant pore structure and high lignin content, was used to develop a novel LV-derived activated biochar (LVAC) with high adsorption capacity and superior selectivity toward methylene blue (MB) from wastewater through a simple one-step carbonization method. The obtained LVAC possessed big pore volume (0.6455 cm3·g−1) and large specific surface area (1075.17 m2·g−1). Importantly, benefiting from the multi-level porous structure and abundant exposed active sites, LVAC demonstrated a large adsorption capacity of 559.11 mg·g−1 toward MB, surpassing that of the majority of previously reported activated carbon. The behavior characteristics of MB adsorption fitted both Freundlich model and pseudo-second order (PSO) model, which was mostly ascribed to the synergistic effect among pore-filling, hydrogen bonds, electrostatic interactions, and π–π interactions. The removal efficiency of LVAC toward MB remained 83 % after eight adsorption–desorption cycles, indicating its excellent recyclability. This study demonstrates the significant potential of LVAC as a candidate for efficient MB removal. [Display omitted] • Activated biochar (LVAC) with multi-level porous structure was fabricated using waste luffa vine as raw material. • LVAC had large pore volume and high specific surface area (1075.17 m2×g−1). • LVAC exhibited excellent adsorption capacity (559.11 mg×g−1) and selectivity toward methylene blue. • Adsorption mechanism was associated with π–π interaction, electrostatic interaction and hydrogen bonding. [ABSTRACT FROM AUTHOR]

[Display omitted] • An amino-functionalized COF was synthesized via a thiol-ene click reaction. • The COF TAPT-DVA-NH 2 showed a significantly enhanced affinity toward DCF. • Rapid kinetics, large adsorption capacity and good recyclability were obtained. • Adsorption was driven by electrostatic, π-π, hydrophobic and hydrogen bond interactions. The presence of diclofenac sodium (DCF) is widespread in environmental waters, leading to issues for ecosystems and human health. Hence, the removal of DCF from aquatic environments is crucial. This study innovatively designed and proposed an urchin-like covalent organic framework (COFs) with affinity groups to enhance its selective adsorption capacity for DCF. As a proof-of-concept, an amine-functionalized COF (TAPT-DVA-NH 2) was synthesized via the thiol-ene click reaction between vinyl-COF (TAPT-DVA) and cysteamine for the purpose of adsorbing DCF from water. The adsorption kinetics, isotherms, the influences of pH, ionic strength, and regeneration of TAPT-DVA-NH 2 for DCF were investigated thoroughly. The synthesized COF TAPT-DVA-NH 2 exhibited exceptionally rapid and efficient DCF capture. The rate constant k 2 was 0.0196 g/mg/min, and the maximum adsorption capacity could reach approximately 398.4 mg/g. The exceptional adsorption performance of COF TAPT-DVA-NH 2 was attributed to electrostatic, π-π, hydrophobic and hydrogen bond interactions. The adsorption efficiency of DCF on COF TAPT-DVA-NH 2 remained above 95 % even after five regeneration cycles. In addition, the self-made adsorbent efficiently adsorbed DCF from real environmental water samples. Thus, this highly efficient and recyclable adsorbent holds significant potential for DCF removal from aquatic environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • One-step synthesis of monoporous silica hollow spheres by microemulsion method. • Single porous silica hollow spheres loaded with microorganisms and encapsulated with nanoscale silica to form a μm-scale core–shell structure bioreactor. • The core–shell structure bioreactor has excellent oil–water separation and emulsion breaking ability, as well as high biodegradability. Highly efficient elimination and disposal of oils and organic contaminants from water is of great importance for the sustainable development of modern society. In this work, micron-sized "single pore" silica hollow spheres (SHMs) bioreactors were prepared using (W/O/W) ternary-phase microemulsion, and the size of pores was adjusted to the concept of "single-pore" composite microorganism bioreactor, preparation of single-pore silica hollow spheres with an average pore size of 8.572 μm, which enables the SHMs bioreactors to load microorganisms for oils biodegradation. The outer layer was sprayed with a layer of silica nanoparticles with a diameter of 500 nm produced by silane hydrolysis, which encapsulated the inner "single-pore" SHMs to form a core–shell structure (M/Microbe@SHMs). This micro-nano core–shell structure exhibits superhydrophobicity and superlipophilicity, which gives it excellent selective adsorption capacity. Interestingly, M/Microbe@SHMs have excellent emulsion-breaking effects in oil–water separation. In addition to the simultaneous oil/water separation ability, the adsorbed oil and grease can be subsequently degraded to CO 2 and H 2 O by microorganisms' action in the inner layer of M/Microbe@SHMs. Based on this excellent selective adsorption and oil/water separation capacity, while one-step in-situ biodegradation, our microbial bioreactor may have a potential for a wide range of practical applications in wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • M-TzDha-COF with β-diketone was prepared by grafting of Meldrum's acid. • M-TzDha-COF retains porous crystalline structure with high thermal stability. • M-TzDha-COF can selectively adsorb methylene blue. • Adsorption behavior includes both chemisorption and physical adsorption. • M-TzDha-COF can be recycled and reused. In this paper, M-TzDha-COF composed of 4,4′,4″-(1,3,5-triazine-2,4,6-triyl) trianiline (Tz) and 2,5-dihydroxy-1,4-benzenedicarboxaldehyde (Dha) was synthesized by grafting carboxyl groups onto COF framework via the solvent-free esterification. M-TzDha-COF retains the porous structure and has good crystallinity and high thermal stability. M-TzDha-COF exhibits selective adsorption and efficient removal of methylene blue dye with the maximum adsorption capacity of 95 mg·g−1. M-TzDha-COF can adsorb methylene blue rapidly and maintain high adsorption efficiency after several cyclic applications. The adsorption of methylene blue on M-TzDha-COF is consistent with the pseudo-second-order adsorption kinetic model and Langmuir adsorption model. Adsorption is caused by three interactions: π-π stacking between the triazine group and methylene blue, electrostatic interaction between the carboxyl group and the methylene blue cationic portion, and hydrogen bonding interaction. Fast kinetics, high adsorption capacity and good reusability make carboxyl functionalized COF have great potential in removing methylene blue dye from water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Branched aminated lignin-based hydrogels (BALH) were successfully fabricated. • Hydrogel has tunable pores and surface charge depending on the lignin and PEI ratio. • The adsorption capacity for MO reached approximately 900–930 mg/g. • BALH can selectively adsorb cationic/anionic dyes. • BALH maintain high removal efficiency after 10 recycles and continuous adsorption. This study introduces a branched aminated lignin-based hydrogel (BALH) designed for the efficient removal of ionic dye pollutants from wastewater. BALH was fabricated using lignin and branched polyethylenimine with poly(ethylene glycol) diglycidyl ether as a crosslinker. BALH exhibited enhanced chemical durability and physical stability; it formed a robust three-dimensional network through polyelectrolyte complexation and chemical crosslinking. BALH demonstrated superior adsorption capacities for both cationic methylene blue and anionic methyl orange (MO) compared to traditional kraft lignin. The adsorption capacity for MO reached approximately 900–930 mg/g, following a pseudo-second-order kinetic model and the Langmuir isotherm model, indicating chemisorption and homogeneous monolayer adsorption. Thermodynamic studies revealed the spontaneous endothermic nature of the adsorption process. Remarkably, BALH maintained a high removal efficiency even after 10 adsorption and desorption cycles, and continuous adsorption experiments confirmed its practical effectiveness. Because of its ultrahigh dye-removal capacity, structural stability, recyclability, and ease of separation, BALH is a promising candidate for scalable wastewater treatment solutions. The study of lignin modification may also offer innovative systems for modifying and cross-linking lignin. [ABSTRACT FROM AUTHOR]

A critical consideration in the application of phytoremediation to remediate sludge soil contaminated with heavy metals is the potential for leaching risks that prevail prior to the efficient uptake of these metals by plants. The most cost-effective method is to use heavy metal stabilizers with selective adsorption. A novel amide-based COF material (COF-TH) has been synthesized as a heavy metal stabilizer for Pb. COF-TH exhibits significant selectivity for Pb in five-metal-mixed solutions, with a distribution coefficient K D as high as 3279 mL·g–1, which was more than 7.3 times that of other heavy metals. The maximum adsorption capacity of COF-TH for Pb was 189 mg·g–1. The adsorption fitted Langmuir model and intra-particle diffusion model, and satisfied pseudo-second-order kinetic model. The excellent selectivity and adsorption performance originate from the complexation between abundant amide groups and Pb ions. Pot experiments and leaching assays confirm that COF-TH decreased Pb leachate concentrations by 77.8 % without significantly decreasing total phytoextracted amounts of other heavy metals, due to the high selectivity of COF-TH to Pb. Additionally, its positive impact on plant growth and microbial diversity makes it a promising soil remediation agent. This investigation offers a novel approach to mitigate the leaching risk of a specific heavy metal Pb during sludge land application by integrating soil phytoremediation with stabilization techniques. [Display omitted] • A novel amide-based COF material (COF-TH) is synthesized by solvent method. • COF-TH has a good selective adsorption for Pb due to its rich amide groups. • COF-TH significantly reduces the leaching risk of Pb in polluted soil. • COF-TH does not affect soil microbial diversity and promotes the plant growth. • COF-TH does not mitigate the phytoextraction of other non-target heavy metals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Selective Fe-La-CS composite microspheres were prepared. • It has selective adsorption properties in a wide pH range of 3–9. • The structure–activity relationship and adsorption mechanism between Fe-La-CS composite microspheres and arsenate were elucidated. In this study, an Fe-La-CS adsorbent with a reticulated structure was prepared by an in situ method, which was able to adsorb arsenate efficiently over a wide pH range of 3–11. The incorporation of iron and lanthanum ions broadened the tolerant pH range of the adsorbent compared with chitosan beads (CS). Arsenic was mainly present in the pH range of 3–9 as two forms, H 2 AsO 4 − and HAsO 4 2−. Calculations using the density-functional theory (DFT) showed that in the Ligand interactions and electrostatic interactions dominate in the pH range, with surface precipitation, and hydrogen bonding interactions playing a facilitating role. The background ions mainly compete with arsenic adsorption for electrostatic interaction sites. However, due to the different valence states of the background ions, the competition intensity is different. Such as low valence state representative ions Na+, K+ competitiveness is weak, and arsenic competition adsorption first occupy different adsorption sites, therefore, from the quantum chemistry and molecular dynamics point of view of Na+, K+ on arsenic adsorption almost no effect. Cl−, SO42− will have some influence on arsenic adsorption because of the same charge with arsenic, but the charged amount is smaller than arsenic and the molecular structure is different from that of arsenic, so the influence is not very big. In summary, the material design of Fe-La-CS adsorbent has great potential and theoretical significance for selective purification of heavy metal wastewater at wide pH. [ABSTRACT FROM AUTHOR]

[Display omitted] • Petal-Like LaCO 3 OH on biochar efficiently captures low concentration phosphorus. • New adsorbent shows superior pH tolerance compared to other biochars. • La-BC has an excellent selective adsorption for phosphorus in water. • The mechanisms in low and high concentration phosphorus adsorption were deciphered. Effectively managing phosphorus (P) concentrations in waterbody is essential to curb eutrophication. In this study, we employed wetland plant Canna indica straw to create biochar and synthesized a distinctive two-dimensional (2D) petal-shaped LaCO 3 OH biochar adsorbent (La-BC). This novel material exhibited outstanding adsorption capabilities for capturing low-concentration P, surpassing unmodified BC by 2–4 times. La-BC showed a rapid adsorption capacity, achieving 97.01 % to 99.10 % removal efficiency within 10 h for 0.5 mg/L and 1.0 mg/L P concentrations. Its maximum P adsorption capacity was recorded at 129.4 mg/g. Considering both environmental safety and P removal efficiency, the optimal pH range for La-BC is 4.0 to 11.0. Adsorption experiments have demonstrated that the adsorption mechanism involves electrostatic attraction and ligand exchange under acidic conditions, with ligand exchange predominating in alkaline environments. Density Functional Theory (DFT) demonstrated that the absolute value of adsorption energy (E ads) is as followed: HPO 4 2− (2.43) > H 2 PO 4 − (2.27) > humic acid (0.613), indicates that La-BC preferentially saturated adsorbs HPO 4 2−, H 2 PO 4 − and then adsorbs humic acid (HA). When the concentration of HA reaches 50 mg/L, which is 50–100 times higher than the P, the removal rate of P by La-BC decreases slightly, but it is still higher than 90 %. La-BC exhibits excellent adsorption selectivity towards P, with no interference from co-existing anions (Cl−, NO 3 –, SO 4 2−, CO 3 2–) in water. Our findings provided a highly efficient, pH-stable, and promising biochar-based solution for the removal of low concentrations of P. [ABSTRACT FROM AUTHOR]

[Display omitted] • Polymeric ionic liquid (PIL) is chemically bonded into the micropores of GAC through radical polymerization. • PIL modification significantly increases positively-charged imidazole N and adsorption energy towards perchlorate. • PIL-GAC shows high selective adsorption capacity of 300.05 mg/g within the pH range of 4–10. • Perchlorate adsorption occurs by electrostatic interaction, ion exchange and hydrogen bond. The study developed a novel adsorbent for improving perchlorate removal efficiency by anchoring Poly (ionic liquid) (PIL) onto granular activated carbons (GACs) via radical polymerization. The authors characterized the physical–chemical properties of GAC modified by PIL (PIL-GAC), and investigated its performance and mechanism for perchlorate adsorption. The results show that the introduction of dicationic ionic liquids dramatically increases the positively charged nitrogen (12.59 %) and point of zero charge (pH pzc = 9.79) of GAC, resulting in a higher attraction for perchlorate. Density Functional Theory (DFT) calculations reveal a better adsorption energy (−162.58 kJ/mol) of perchlorate on imidazole N, highlighting its potential selectivity over other N and O functional groups. PIL-GAC exhibits a maximum adsorption capacity (Q m) of 300.05 mg/g at 25 °C, which is 12 times higher than that of pristine GAC and better than previously reported adsorbents. Additionally, this Q m is pH independent within pH 4 to 10. The perchlorate adsorption on PIL-GAC fits the Langmuir (R2 ≥ 0.98) and pseudo second order kinetic (R2 > 0.99) models, indicating a spontaneous process primarily driven by chemisorption. Remarkably, PIL-GAC also exhibits sustainable regeneration and greater selectivity for perchlorate with a lower hydration energy (−214 kJ/mol), over nitrate, chloride, and sulfate with higher hydration energy (−306, −347, and −1090 kJ/mol). After adsorption, PIL-GAC demonstrates a decrease of N+ and an increase in Cl-, indicating that perchlorate adsorption of PIL-GAC mainly involves electrostatic interaction and ion exchange. Therefore, this study offers a promising method for efficient and selective removal of perchlorate from water. [ABSTRACT FROM AUTHOR]

Organic matter blocks highly selective frayed edge sites on clay minerals and reduces radiocaesium adsorption. The effects of different soil organic matter on Cs adsorption on illite have been investigated. The quantity and quality of soil organic matter was varied by extracting from three contrasting soils and varying extraction conditions. Extracted organic matter was quantified, and analysed using UV and fluorescent spectroscopy. Cs adsorption was markedly lower in soil aqueous extracts, than in simple electrolyte solution at the same ionic strength (IS). Part of the decrease was attributed to soluble soil potassium. After correction for ionic strength and potassium, the relative distribution coefficient of Cs, Kd IS,K , decreased with increasing dissolved organic carbon (DOC) concentration. The correlation between Kd IS,K and DOC was largely unchanged by taking into account any of the measured spectral parameters. We find no evidence that molecular size and composition of organic coatings determine their effect on the Cs adsorption properties of illite. • Soil aqueous extracts induced marked decreases in radiocesium adsorption on illite. • Both dissolved organic matter and potassium contributed to decreased adsorption. • Cs adsorption on illite was determined by the amount of organic matter. • No evidence that FES blockage depended on the nature of dissolved organic matter. [ABSTRACT FROM AUTHOR]

To address the urgent need for efficient removal of lead-containing wastewater and reduce the risk of toxicity associated with heavy-metal wastewater contamination, materials with high removal rates and easy separation must be developed. Herein, a novel organic-inorganic hybrid material based on phosphorylated magnetic chitosan (MSCP) was synthesized and applied for the selective removal of lead (II) from wastewater. From the characterization and the experimental results can be obtained that the magnetic saturation strength of MSCP reaches 14.65 emu/g, which can be separated quickly and regenerated readily, and maintains high adsorption performance even after 5 cycles, indicating that the adsorbent possesses good magnetic separation performance and durability. Also, MSCP showed high selective adsorption performance for lead in the multiple metal ions coexistence solutions at pH 6.0 and room temperature, with an adsorption coefficient S Pb-MSCP of 78.85%, which was much higher than that of MSC (the S Pb-MSC was 11.59%). Additionally, in the single lead system, the sorption characteristics of Pb(II) on MSCP and MCP had obvious pH-responsiveness, and their adsorption capacity increased with the increase of solution pH, reaching the maximal values of 80.19 and 72.68 mg/g, respectively. It is noteworthy that the acid resistance of MSCP with an inert layer coated on the core is significantly improved, with almost no iron leaching from MSCP over the entire acidity range, while MCP has 7.63 mg/g of iron leaching at pH 1.0. Significantly, MSCP exhibited a maximum adsorption capacity of 102.04 mg/g, which matches the Langmuir model at pH 6.0 and 298.15 K, and points to the pseudo-second-order kinetics of the chemisorption process of Pb(II) on MSCP. These findings highlight the great potential of MSCP for Pb(II) removal from aqueous solution, making it a promising solution for Pb(II) contamination in wastewater. • A novel phosphorylated magnetic adsorbent (MSCP) was synthesized. • The high magnetism of MSCP enabled the rapid solid-liquid magnetic separation. • Competitive adsorption experiment showed highly selective lead adsorption. • Regeneration cycle experiments to verify the durability of MSCP. • The mechanism of lead adsorption by MSCP was clarified. [ABSTRACT FROM AUTHOR]

[Display omitted] • TNFs were synthesized via a one-step hydrothermal method. • TNFs reached 691.3 mg m−2 adsorption for Tl(III) in NH 4 ReO 4 solution. • TNFs exhibited stability across pH 2–8 with no Ti dissolution. • TNFs provided abundant hydroxyl groups for substantial Ti-O-Tl generation. A highly effective, stable, and recyclable adsorbent based on titanium dioxide nanofibers (TNFs) was fabricated via a one-step hydrothermal synthesis. The application of TNFs for the deep removal of thallium (Tl) from ammonium perrhenate (NH 4 ReO 4) solutions was investigated. The effect of different factors, including hydrothermal temperature and time (120–170 °C, 4–10 h), adsorbent surface area (3–12 cm2), initial concentration of Tl(III) (2–10 mg/L) and pH (2–10) on the removal performance, was analyzed using batch adsorption experiments. Kinetic analysis revealed that the removal process followed a pseudo-first-order model. The adsorption data of TNFs were analyzed using Freundlich and Langmuir isotherms, with the Langmuir isotherm showing the best fit and indicating a theoretical maximum adsorption capacity of 767.2 mg m−2. Thermodynamic studies demonstrated the adsorption process was characterized by physisorption, being spontaneous, and exothermic. Under optimized conditions, TNFs demonstrated successful removal of Tl(III) from NH 4 ReO 4 solutions with limited adsorption of rhenium (Re) and arsenic (As) ions. Acidity and reusability tests confirmed the significant stability and excellent recoverability of TNFs. The proposed TNFs serve as an effective, and stable adsorbent with a high affinity for Tl(III), offering a viable and efficient approach for the purification of NH 4 ReO 4 solutions. [ABSTRACT FROM AUTHOR]

Improving the adsorption capacity of activated carbon (AC) for volatile organic compounds (VOCs) in humid conditions, while suppressing the interference of water molecules on the adsorption process, is significant for maximizing the effectiveness of AC as an adsorbent for efficient VOC removal. This paper investigates the impact of water on benzene adsorption by nitrogen-doped activated carbon (ACN), the hydrophobicity of different nitrogen-doped types, and the effects of methyl on the selective adsorption of benzene by ACN. The investigation is based on experiments and DFT simulations, and the corresponding mechanisms were elucidated through the force field-based energy decomposition analysis (EDA-FF), the independent gradient model based on Hirshfeld partition (IGMH), and the atoms in molecules (AIM). Under the coexistence of benzene and water, a van der Waals (vdW) interaction occurs between the adsorbed water molecules and benzene molecules, which seriously impairs benzene adsorption on ACN. Pyridine and pyrrole N enhance the adsorption of water by increasing the electrostatic interaction between water molecules and AC. Methyl group reduces hydrophilicity by increasing the repulsion of pyridine and pyrrole nitrogen with water. The selective adsorption of benzene on ACN was improved by enhancing the dispersion effect with benzene. The experimental results showed that after ACN modification with the methyl, benzene adsorption was completely restored to the situation when there was no water interference. This confirms that nitrogen-methylation is an effective method for enhancing benzene adsorption by AC while suppressing water interference. [Display omitted] • The mechanism of H 2 O interference with C 6 H 6 adsorption was revealed. • Repulsion between H 2 O and C 6 H 6 inhibits the adsorption of C 6 H 6. • The hydrogen bond between pyridine N, pyrrole N and H 2 O promotes adsorption. • The regulatory mechanism of nitrogen methylation was elucidated. • Nitrogen methylation enhances C 6 H 6 adsorption and inhibits H 2 O interference. [ABSTRACT FROM AUTHOR]

The heavy metal lead (Pb) holds significant importance in the manufacturing industry due to its extensive range of applications. However, its high toxicity poses a serious risk to both environment and human health. Consequently, on-site portable analysis methods have been developed to detect Pb2+, which is advantageous for obtaining timely information regarding environmental pollution. In this study, a fungal-like porous CoS (FP CoS) was discovered to selectively recognize, adsorb, and detect Pb2+. FP CoS exhibited rapid kinetics (reducing from 8.56 mg∙L–1 to 69 µg∙L–1 within 30 min) as well as exceptional adsorption capacity of 88.14 mg∙g−1 for Pb2+. Benefiting from the selective enrichment of Pb2+, the peroxidase-like activity of FP CoS nanoenzyme was further enhanced, enabling colorimetric detection of Pb2+ with a detection limit of 14 ng∙L–1, surpassing numerous reported materials. When applied to environmental samples spiked with 0–100 μg∙L–1 Pb2+, the combination of FP CoS nanosensor and a portable RGB color sensor yielded an impressive recovery percentage of 112 %. Based on these results, the FP CoS nanosensor not only provides a rapid and visually discernible colorimetric approach for trace and ultra-trace Pb2+ but also serves as a sensitive sensor for detecting Pb2+ in various scenarios. [Display omitted] • A fungal-like porous CoS (FP CoS) for the adsorption, removal and monitoring of Pb2+ was generated. • After selective enrichment of Pb2+, the peroxidase-like activity of FP CoS nanoenzyme was further enhanced. • When coupling to an integrated enrichment-detection strategy utilizing the RGB sensor, a detection limit as low as 0.014 μg L−1. • FP CoS nanosensor detect Pb2+ in river water with impressive recoveries of 112–117 %. • The current results provide a new avenue to the on-site detection of Pb2+ ions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of carbon materials with different functional groups and pore structures were fabricated. • The effects of pore sizes, functional groups, and applied voltage on nitrate selective removal were systematically investigated. • The increase of voltage enhances interfacial electron transport and nitrate mass transfer. • Functional groups drive microporous ion sieving through electrostatic interaction to improve nitrate removal selectivity. In the presence of coexisting ions, the limited selectivity hampers the application of NO 3 – adsorption. Herein, a series of NO 3 – adsorbents featuring adjustable degrees of functional groups and pore structures were synthesized to explore their structure–activity relationship at atomic level. The effects of pore sizes, functional groups, and applied voltage on the selective removal of NO 3 – were systematically investigated. Theoretical calculations and experiments confirmed that pore sieving effect and electrostatic attraction provided by functional groups synergically enhance NO 3 – selectivity. The applied voltage changes the interfacial microenvironment of adsorbent and improves the interfacial electron transmission, thus promoting NO 3 – transfer and enrichment on adsorbent surface. Meanwhile, increasing electrostatic attraction can not only increase the adsorption capacity but also improve the selective screening of anions by micropores. Driven by an external voltage of 1.2 V, NO 3 – selectivity of ZIF-8-C-Q-2 nearly doubles. Under higher voltage, ZIF-8-C-Q-2 exhibits lower charge transfer resistance and higher ion diffusion capacity, which is conducive to capturing electrolyte ions (NO 3 –), thereby enhancing its adsorption capacity and selectivity. This study provides a novel insight into synergism of functional groups and micropores for selective adsorption of NO 3 – in electrosorption mode. [ABSTRACT FROM AUTHOR]

Owing to the poor treatment efficiency of wastewater containing fluoroquinolones (FQs), effective removal of such pollutants has become a significant issue in waste management. In this study, a ternary covalent organic polymer anchored with SO3H (COP-SO3H) was designed using the Schiff reaction and a multicomponent solvent thermal method. The synthesized COP-SO3H polymer possesses multiple functional binding sites, including amide groups, sulfonic groups, and aromatic frameworks, enabling it to effectively adsorb ciprofloxacin (which belongs to FQs) through mechanisms such as pore-filling effects, electrostatic interactions, hydrogen bonding, π-π electron donor–acceptor (EDA) interactions, and hydrophilic–lipophilic balance. COP-SO3H demonstrated outstanding adsorption performance for ciprofloxacin, exhibiting a high adsorption capacity, broad pH stability, strong resistance to ionic interference, and good regenerability. Moreover, it displayed preferential selectivity toward fluoroquinolone antibiotics. The present study not only investigates the intricate structural and functional design of COP-SO3H materials but also presents potential applications for the efficient adsorption of specific antibiotics.

In this research, a novel collector cetyl trimethyl ammonium chloride (CTAC) was used to separate hematite from quartz via reverse flotation for the first time. Micro-flotation tests showed that CTAC had a strong ability to selectively collect quartz and that a separation of hematite from quartz could be accomplished with a concentration of 0.00263 mmol/L CTAC. Zeta-potential measurements indicated that the positive CTAC+ species could selectively increase the surface potential of quartz, but that it had rather a weak effect on the hematite. X-ray photoelectron spectroscopy (XPS) detection indicated that CTAC had a stronger binding affinity to oxygen sites on the surface of quartz than on hematite, resulting in a large amount of CTAC being predominantly adsorbed onto quartz. This was supported by the atomic concentration of C1s and N1s of quartz after CTAC treatments were 4.25 and 2.84 times higher than hematite, respectively.

A cobalt/manganese-imprinted adsorbent grafted with thiourea (T-Co/Mn-CTS) was synthesized through the combination of the amino groups of thiourea with imprinted chitosan (Co/Mn-CTS) by using a sol-gel method along with a reverse-phase suspension method. Cobalt chloride and manganese chloride were employed as imprint molecules. The structures of the adsorbents were investigated by Fourier transform infrared spectroscopy. The results of static adsorption experiments indicated that the adsorption of Co2+ and Mn2+ occurred in the first 0.5 h, and the absorption capacity of T-Co/Mn-CTS for these ions was higher than that of Co/Mn-CTS. The selective adsorption performance of the template-imprinted-chitosan resin was better than that of the non-imprinted-chitosan resin, in the presence of other ions. The effect of interfering ions on the adsorption performance for Mn2+ was greater than that for Co2+. Dynamic adsorption experiments indicated that the breakthrough volumes of Co2+ and Mn2+ were 110 BV and 14 BV, respectively, with the corresponding breakthrough curves being symmetrical S-type and unsymmetrical S-type.

Abstract Collector OA, oleic acid, is widely used industrially for fluorite flotation. Low selectivity, dispersibility and collecting capability of the OA collector are always observed. In this study, compared with flotation of dolomite, a collector mixture of OA and SPE (styrylphenol polyoxyethylene ether) demonstrated significantly better performances for the fluorite. An optimal mass ratio 4 : 1 OA : SPE was found, and the recovery of fluorite was increased from over 85 % to more than 94 % compared with pure OA. Furthermore, the dosage of the collector agent was reduced from 50 mg mL−1 to 20 mg mL−1, which did not negatively impact the recovery of dolomite. The results from the contact angle tests indicated that SPE selectively increased the surface hydrophobicity of fluorite but had little effect on dolomite. Besides, zeta potential measurements and IR analyses revealed that the addition of SPE led to strong chemical adsorption on the surface of fluorite, resulting in a significant difference in the flotation performances of the two minerals. Therefore, SPE‐emulsified OA is corroborated to prompt more selectivity and collecting capability on flotation of fluorite over dolomite.

Selective recovery of indium has been widely studied to improve the resource efficiency of critical metals. However, the interaction and selective adsorption mechanism of indium/iron ions with tannin-based adsorbents is still unclear and hinders further optimization of their selective adsorption performance. In this study, the epigallocatechin gallate (EGCG) monomer, which is the key functional unit of persimmon tannin, was chosen to explore the ability and mechanism of selective separation/extraction of indium from indium–iron mixture solutions. The density functional theory calculation results indicated that the deprotonated EGCG was easier to combine with indium/iron cations than those of un-deprotonated EGCG. Moreover, the interaction of the EGCG–Fe(III) complex was dominated by chelation and electrostatic interaction, while that of the EGCG–In(III) complex was controlled by electrostatic interactions and aromatic ring stacking effects. Furthermore, the calculation of binding energy verified that EGCG exhibited a stronger affinity for Fe(III) than that for In(III) and preferentially adsorbed iron ions in acidic or neutral solutions. Further experimental results were consistent with the theoretical study, which showed that the Freundlich equilibrium isotherm fit the In(III) and Fe(III) adsorption behavior very well, and the Fe(III) adsorption processes followed a pseudo-second-order model. Thermodynamics data revealed that the adsorption of In(III) and Fe(III) onto EGCG was feasible, spontaneous, and endothermic. The adsorption rate of the EGCG monomer for Fe(III) in neutral solution (1:1 mixed solution, pH = 3.0) was 45.7%, 4.3 times that of In(III) (10.7%). This study provides an in-depth understanding of the relationship between the structure of EGCG and the selective adsorption capacity at the molecular level and provides theoretical guidance for further optimization of the selective adsorption performance of structurally similar tannin-based adsorbents. [ABSTRACT FROM AUTHOR]

Hollow mesoporous silica nanoparticles have been widely applied as a carrier material in the molecular imprinting process because of their excellent properties, with high specific surface area and well-defined active centers. However, these kinds of materials face the inevitable problem that they have low mass transfer efficiency and cannot be conveniently recycled. In order to solve this problem, this work has developed a composite hydrogel microsphere (MMHSG) encapsulated with hollow mesoporous imprinted nanoparticles for the selective extraction of 2'-deoxyadenosine (dA). Subsequently, the hollow mesoporous imprinted polymers using dA as template molecule and synthesized 5-(2-carbomethoxyvinyl)-2′-deoxyuridine (AcrU) as functional monomer were encapsulated in hydrogel. MMHSG displayed good performance in specifically recognizing and quickly separating dA, whereas no imprinting effect was observed among 2′-deoxyguanosine (dG), deoxycytidine (dC), or 5′-monophosphate disodium salt (AMP). Moreover, the adsorption of dA by MMHSG followed chemisorption and could reach adsorption equilibrium within 60 min; the saturation adsorption capacity was 20.22 μmol·g−1. The introduction of AcrU could improve selectivity through base complementary pairing to greatly increase the imprinting factor to 3.79. Therefore, this was a successful attempt to combine a hydrogel with hollow mesoporous silica nanoparticles and molecularly imprinted material. [ABSTRACT FROM AUTHOR]

Copper ion imprinting and colloidal crystal template were used to adsorb in water. Polystyrene microspheres and copper templates were added to form three-dimensional macroporous structure and ion imprinted sites, respectively. In addition, polyvinyl alcohol and montmorillonite were added to modify the membrane materials organically and inorganically, so as to enhance its mechanical properties and stabilize its structure. Finally, the film was formed by drying. The adsorption experiments showed that CS/MMT imprinted composite membrane had a good removal effect on Cu2+ in aqueoussolution. CS/MMT imprinted composite membrane has good adsorption performance and high adsorption efficiency under the neutral condition of pH =7.0. The maximum adsorption capacity of CS/MMT imprinted composite membrane was 230.48mg/g. The adsorption process is more consis tent with the quasi second-order kinetic model and Langmuir isotherm. CS/MMT imprinted composite membrane has good selective adsorption for Cu2+. In addition,it can be regenerated for many times and reused as adsorbent,maintaining a high adsorption capacity. This imprinting template method is of great significance for the selective adsorption of pollutants in bio-materials,and is worth further study. [ABSTRACT FROM AUTHOR]

The laboratory prepared CAM membrane was used as substrate and modified with KH570 to introduce a polymerizable unsaturated bond on the membrane surface. Then, specific recognition sites on MIPs-CAM were constructed via imprinting polymerization process using SA as template, VPBA as functional monomer, and EGDMA as the cross-linker. The surface imprinting method not only makes the molecular imprint sites stably anchor onto the surface of the composite membranes, but also effectively avoids the embedding of the imprinted sites. The specific adsorption and separation performance of MIPs-CAM were achieved owing to the unique covalent binding of boric acid towards cis-diols of SA and spatial binding site for SA molecule. [Display omitted] • Molecular imprinted membrane based on cellulose acetate membrane (CAM) was prepared. • CAM-MIPs possessed multistage structure with reversible pH response effect and stability. • CAM-MIPs possessed specific binding sites for shikimic acid. • CAM-MIPs presented high adsorption capacity, specific affinity and outstanding reusability. Cellulose acetate membrane (CAM) has become one of the most widely used membrane materials by virtue of stability and hydrophilicity. In this work, to achieve the aim of selective recognition and separation of drug molecule shikimic acid (SA), an effective recognition tactics was proposed by combining boron affinity technology with surface imprinting strategy based on cellulose acetate membrane with low price and biocompatibility. The supporting CAM material was prepared through the phase inversion technique by continuous adjustment of different factors including solvent type and kinds of pore-forming agents, and the optimal CAM with multistage structure and highly porosity was applied for the imprinting of SA. Then the imprinted polymer membrane (MIPs-CAM) was developed via boron affinity surface imprinting polymerization. Various methods (FT-IR, UV–vis, SEM, XPS, AFM and TGA) were used to characterize the structure, morphology, elemental composition, surface roughness and thermal property of the obtained membrane. The as-prepared MIPs-CAM showed homogeneous and abundant imprinted layer, good thermal stability. The batch adsorption results showed that the MIPs-CAM had fast adsorption kinetics, specific recognition ability, and the adsorption capacity could obtain 63.598 mg g−1, which was two times higher than that of non-imprinted membrane (NIPs-CAM). The adsorption isotherms conformed to the Langmuir isotherm and the adsorption processes were spontaneous and endothermic. Additionally, the adsorption capacity of MIPs-CAM still reached 85% of the initial result after five cycles. The experimental results revealed that the molecularly imprinted membrane possessed the advantages of high selectivity and easy recovery compared with the traditional molecular imprinted polymers for SA separation. These results indicate that boron affinity MIPs-CAM with high performance will provide a promising platform for the separation and purification of other cis-diol drug molecules from environmental resources. [ABSTRACT FROM AUTHOR]

A graphite‐based ion‐imprinted polymer (G‐IIP) was synthesized using the surface‐printing technique. Allylthiourea was used as the functional monomer, nitrate as the template, and ethylene glycol dimethacrylate as a crosslinker. The polymers were characterized, and the adsorption capacity was tested. The binding ability of G‐IIP was nearly twice higher than that of the graphite‐non‐imprinted polymer (G‐NIP). The adsorption of G‐IIP followed the Freundlich isotherm and the pseudo‐second‐order kinetic. G‐IIP showed good removal efficiency of nitrate ions in actual wastewater samples with 85 % recovery. Overall, the fabricated G‐IIP would be a potential adsorbent for wastewater treatment. [ABSTRACT FROM AUTHOR]

A scalable approach to generating different nanomaterials from the same hydrogen‐bondeded complex by photo‐crosslinking is described. The hydrogen‐bonded complex exhibits a smectic or columnar mesophase, depending on the molar ratio between the donor and acceptor. The mesophase structure is effectively retained after photo‐crosslinking. Polymer nanosheets with negatively charged carboxylate groups can be prepared from the complex with the smectic mesophase after subsequent extraction and chemical treatment, and they show effective adsorption of Pd2+. Meanwhile, a nanoporous polymer is successfully achieved from the complex having the columnar mesophase by using the same technology of photo‐crosslinking and solvent treatment. This work provides a new strategy to fabricate different nanomaterials from the same hydrogen‐bonded complex system. [ABSTRACT FROM AUTHOR]

Activated carbon owning a better adsorption performance as adsorbent was screened out firstly from activated carbon, diatomite, ZSM-5 zeolite, artificial zeolite and other common porous materials. The pore structure and surface functional groups of activated carbon were regulated by acid and alkali modification methods, and the adsorption effect of TDA tar on modified activated carbon was studied by static adsorption experiment. The results showed that the pore structure of activated carbon mainly affected the total adsorption capacity for TDA tar, while the surface functional groups of activated carbon significantly affected the adsorption selectivity for TDA, and the acidic groups were beneficial to enhance the selectivity of TDA. Under the optimal conditions, the adsorption selectivity for TDA of CH3COOH modified activated carbon could reach more than 98%,and the adsorption process of activated carbon modified was controlled by chemical adsorption. Reset [ABSTRACT FROM AUTHOR]

Based on the theory of volume filling of micropores, an analysis of the structural and energy characteristics of model carbon adsorbents for the sorption of xenon and krypton from the depleted gas–air streams was carried out. It was found that the maximum adsorption capacity for Xe and Kr was achieved at a pore size ranging from ~0.8 to 0.9 nm. The adsorption of Хе, Kr, N2, and О2 onto T-3 activated carbon with the effective width of micropores of 0.94 nm was investigated at pressures up to 100 kPa and at a temperature of 293 K. It was shown that such an adsorbent can be effectively used to capture Xe and Kr from depleted gas–air streams. [ABSTRACT FROM AUTHOR]

A MOF named [(CH3)NH2] [H2N(CH3)2][ZnTNC4A] ⋅ 4H2O (ZnTNC4A) was synthesized by a resorcinol[4]arene functionalized tetracarboxylic acid ligand (TNC4A=2,8,14,20‐tetra‐1‐naphthalene‐6,12,18,24‐tetramethoxy‐4,10,16,22‐ tetracarboxyl‐methoxy‐resorin[4]arene). The three‐dimensional framework with one‐dimensional channels of ZnTNC4A was characterized by elemental analysis, powder X‐ray diffraction, thermogravimetry, UV‐vis diffuse reflection spectrum, infrared spectrum and N2 adsorption analyse. In addition, ZnTNC4A shows the ability of selective adsorption of methylene blue with a pseudo‐second order kinetic model. The selective adsorption kinetics of a series of dyes showed that the ion exchanged separation process was related to the size and charge of organic dyes. [ABSTRACT FROM AUTHOR]

Efficient and simultaneous removal of anionic and cationic dyes from wastewater using low-cost and environmentally-friendly adsorbent is highly required. Herein, the carboxylated cellulose (carboxyl content: 2.97 mmol/g) derived from pomelo peel was extracted by a one-step H 2 O 2 /H 2 SO 4 -mediated oxidation method. Subsequently, a novel pomelo-peel cellulose/chitosan/sodium alginate (PCS) amphoteric aerogel with a specific core-shell structure was synthesized by multiple physical cross-linking strategies. The shell layer and core layer of the optimized P 3 CS 0.75 aerogel can selectively adsorb cationic dyes and anionic dyes, in which, the theoretical maximum adsorption capacities were 888.27 mg/g and 1816.87 mg/g towards methylene blue (MB) and Congo red (CR), respectively. Especially, the aerogel's core/shell layer exhibited hierarchical adsorption behavior without overlapping sites even in the binary dye systems. The adsorption performance of obtained amphoteric aerogel remained effective in a wide pH range and under different practical water systems. Moreover, the removal efficiencies for MB and CR were slightly reduced from 90.76 % and 99.66 % to 88.08 % and 91.39 %, respectively, after 5 adsorption-desorption cycles, and the aerogel's structural integrity was also maintained due to its good compressive strength (487.16 KPa). In addition, the adsorption mechanism of PCS aerogel was investigated using adsorption kinetics, isotherm, thermodynamics, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. It was proved that the adsorption process was endothermic spontaneous-monolayer adsorption driven by electrostatic attraction and hydrogen bonding. Therefore, the prepared biobased aerogel was expected to be a prospective material for removing mixed dyes from wastewater., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)