Highly efficient removal of aqueous phosphate via iron-manganese fabricated biochar: Performance and mechanism.

Biochar (BC) has emerged as a potential solution to phosphate removal from wastewater primarily resulting from global overuse of fertilizers. Further modification by embedment of iron (Fe)-manganese (Mn) oxides on BC can enhance phosphate removal; however, the modification method serves as a vital factor underlying distinctive removal performances and mechanisms, which have yet been systematically examined. Herein, two Fe-Mn modified BC, Fe/MnBC (comprised of Fe3O4 and MnO2) and Fe-MnBC (comprised of MnFe2O4), were comprehensively investigated for gaining insights into the unsolved perspectives. The results indicated that Fe-MnBC exhibited a markedly greater maximum phosphate adsorption capacity of 135.88 mg g-1 than that of Fe/MnBC with 17.93 mg g-1. The comparative results based on microstructure and spectroscopic analyses suggested that different Fe and Mn oxides were successfully loaded, which played a distinctive role in phosphate removal. Further characterizations unveiled that the key mechanisms for phosphate removal by Fe/MnBC are inner-sphere complexation and precipitation, while electrostatic interaction and outer-sphere complexation are the dominant mechanisms underlying the notable performance of Fe-MnBC. The delicately designed Fe-MnBC with special structure and property also enabled a superior regeneration capacity, which presented a promisingly high phosphate removal efficacy of over 81.34% after five cycles. These results enhance comprehension regarding the impact of biochar modification techniques on phosphate removal, offering positive indications for the remediation of excessive phosphate and other pollutant-containing water through feasible design and green chemicals.

Arsenic adsorption by different Fe-enriched biochars conditioned with sulfuric acid.

In this study, ferric chloride and sulfuric acid were used to increase the Fe-containing minerals on the biochar surface before a pyrolysis at 600 °C. The pristine and Fe-modified biochars prepared at different concentrations of sulfuric acid (50FBC and 72FBC) were characterized and analyzed, and their capacity of As(V) adsorption under various pH and ionic strength were evaluated. The results showed that the maximum adsorption capacities of As(V) calculated by the Langmuir model for 50FBC and 72FBC are 10.33 and 15.61 mg g-1, respectively, which are enhanced by 5.0 and 7.8 times compared with the pristine biochar. The higher dosage of H2SO4 (72%) used in the modification leads to a better adsorption capacity of As, especially under neutral to alkaline conditions (7.0 < pH < 10.0). It might result from the increased amounts of Fe-containing minerals formed on the biochar surface, and the enriched functional groups such as phenolic hydroxyl and carboxyl, resulting in the resistance to alkaline conditions. Overall, the Fe-modified biochar, especially 72FBC, had good potential as an environmentally friendly adsorbent for removing As from contaminated water under a wider pH range.

Understanding the microfluidic generation of double emulsion droplets with alginate shell.

The monodisperse double emulsions obtained by microfluidic method can serve as ideal templates for preparing core-shell alginate microcapsules, which have attracted much attention in biological applications, such as drug delivery systems and cell encapsulation, tissue engineering. However, the formation behavior and dynamic analysis of double emulsion with an alginate shell is still unclear due to the complex rheological behavior of alginate solutions. Herein, we employ a dual-coaxial microfluidic device to generate the high-quality double emulsion droplets with alginate shell, focusing on the effects of the fluid properties of alginate solution in the middle phase (viscosity, µm) and the fluid flow rate on the droplet formation mechanism. As the viscosity of the middle fluid (µm) increased, the size of compound droplets (D2) increased and the size of inner droplets (D1) decreased, and the break-up regimes occurred a dripping-to-jetting transition when µm = 160 mPa s. The number of encapsulated inner droplets can be predicted and precisely controlled by regulating the generation frequency of inner (f1) and outer droplets (f2). The breakup dynamics of the alginate thread are also analyzed by using the volume-of-fluid/continuum-surface-force (VOF/CSF) method. The results show that the pressure and velocity in the neck of pinch-off is lower in the jetting than that in the dripping regime. This study will provide useful guidance for the rational design and controllable preparation of core-shell alginate microcapsules.

Efficacy of Super-Mini-PCNL and Ureteroscopy in Kidney Stone Sufferers and Risk Factors of Postoperative Infection.

To investigate the efficacy of super-mini-PCNL (SMP) and ureteroscopy in kidney stone (KS) sufferers and learn the risk factors of postoperative infection. A retrospective analysis was performed on 180 KS sufferers who were diagnosed and treated in our hospital from May 2019 to May 2021. They were enrolled into an observation group (OG, n = 104) and a control group (CG, n = 76) based on different treatment methods. Therein, the former was treated with SMP, while the latter was treated with ureteroscopy. The operation time, blood loss, hospital stay, recent stone-free rate (one week after operation), changes of serum creatinine (SCr), blood urea nitrogen (BUN), and cystatin C (CysC) levels before and after operation and complications were compared. Those sufferers were assigned to infected and uninfected groups based on their postoperative infection. The risk factors were assessed through logistic regression, and the model formula was established. The predictive value of this model for infection was tested through RO. Compared with CG, the operation time of the OG was longer, the blood loss and hospital stay were lower (P < 0.05), and the stone-free rate was higher (P < 0.05). Renal function indexes before and after treatment (P > 0.05) and postoperative complications revealed no significant difference (P > 0.05). Logistic regression analysis manifested that preoperative urinary tract infection (OR: 4.690, 95% CI: 1.170-18.802), preoperative blood glucose level (OR: 11.188, 95% CI: 2.106-59.442), positive urine culture (OR: 10.931, 95% CI: 2.453-48.705), and infectious stones (OR: 3.951, 95% CI: 1.020-15.300) were independently related to infection. The risk prediction equation is logit(p)=-8.913+1.545 × X1+2.415 × X2+2.392 × X3+1.374 × X4, with a goodness-of-fit value of 0.545. The AUC is 0.930, so SMP is superior to ureteroscopy in KS sufferers. Preoperative urinary tract infection, preoperative blood glucose level, positive urine culture, and infectious stones are independently related to infection.

Phosphate Removal Mechanisms in Aqueous Solutions by Three Different Fe-Modified Biochars.

Iron-modified biochar can be used as an environmentally friendly adsorbent to remove the phosphate in wastewater because of its low cost. In this study, Fe-containing materials, such as zero-valent iron (ZVI), goethite, and magnetite, were successfully loaded on biochar. The phosphate adsorption mechanisms of the three Fe-modified biochars were studied and compared. Different characterization methods, including scanning electron microscopy/energy-dispersive spectrometry (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), were used to study the physicochemical properties of the biochars. The dosage, adsorption time, pH, ionic strength, solution concentration of phosphate, and regeneration evaluations were carried out. Among the three Fe-modified biochars, biochar modified by goethite (GBC) is more suitable for phosphate removal in acidic conditions, especially when the pH = 2, while biochar modified by ZVI (ZBC) exhibits the fastest adsorption rate. The maximum phosphate adsorption capacities, calculated by the Langmuir-Freundlich isothermal model, are 19.66 mg g-1, 12.33 mg g-1, and 2.88 mg g-1 for ZBC, GBC, and CSBC (biochar modified by magnetite), respectively. However, ZBC has a poor capacity for reuse. The dominant mechanism for ZBC is surface precipitation, while for GBC and CSBC, the major mechanisms are ligand exchange and electrostatic attraction. The results of our study can enhance the understanding of phosphate removal mechanisms by Fe-modified biochar and can contribute to the application of Fe-modified biochar for phosphate removal in water.

Two Facile Aniline-Based Hypercrosslinked Polymer Adsorbents for Highly Efficient Iodine Capture and Removal.

Effective capture and safe disposal of radioactive iodine (129I or 131I) during nuclear power generation processes have always been a worldwide environmental concern. Low-cost and high-efficiency iodine removal materials are urgently needed. In this study, we synthesized two aniline-based hypercrosslinked polymers (AHCPs), AHCP-1 and AHCP-2, for iodine capture in both aqueous and gaseous phases. They are obtained by aniline polymerization through Friedel-Crafts alkylation and Scholl coupling reaction, respectively, with high chemical and thermal stability. Notably, AHCP-1 exhibits record-high static iodine adsorption (250 wt%) in aqueous solution. In the iodine vapor adsorption, AHCP-2 presents an excellent total iodine capture (596 wt%), surpassing the most reported amorphous polymer adsorbents. The rich primary amine groups of AHCPs promote the rapid physical capture of iodine from iodine water and iodine vapor. Intrinsic features such as low-cost preparation, good recyclability, as well as excellent performance in iodine capture indicate that the AHCPs can be used as potential candidates for the removal of iodine from radioactive wastewater and gas mixtures.

Record Complexity in the Polycatenation of Three Porous Hydrogen-Bonded Organic Frameworks with Stepwise Adsorption Behaviors.

Hydrogen-bonded organic frameworks (HOFs) show great potential in many applications, but few structure-property correlations have been explored in this field. In this work, we report that self-assembly of a rigid and planar ligand gives rise to flat hexagonal honeycomb motifs which are extended into undulated two-dimensional (2D) layers and finally generate three polycatenated HOFs with record complexity. This kind of undulation is absent in the 2D layers built from a very similar but nonplanar ligand, indicating that a slight torsion of ligand produces overwhelming structural change. This change delivers materials with unique stepwise adsorption behaviors under a certain pressure originating from the movement between mutually interwoven hexagonal networks. Meanwhile, high chemical stability, phase transformation, and preferential adsorption of aromatic compounds were observed in these HOFs. The results presented in this work would help us to understand the self-assembly behaviors of HOFs and shed light on the rational design of HOF materials for practical applications.

Graphene quantum dots: efficient mechanosynthesis, white-light and broad linear excitation-dependent photoluminescence and growth inhibition of bladder cancer cells.

Heteroatom-doped graphene quantum dots (GQDs) have attracted considerable attention due to their potential applications as luminescent materials and in biology. In this work, we developed a solvent-free gram-scale mechanochemical method for the preparation of nitrogen-doped graphene quantum dots (N-GQDs) with the highest solubility (31 mg mL-1) in water reported to date. Commercial graphite was sheared and cut through grinding with solid melamine and then ground with solid KOH to get sub-5 nm-sized, 1-3-layered N-GQDs. Notably, these N-GQDs exhibit white-light emission and broad excitation-dependent full-color photoluminescence from 463 nm to 672 nm. When the excitation light ranged from 325 nm to 485 nm, these mechanochemically obtained N-GQDs exhibited bright white-light emission. Intriguingly, the change in the emission wavelength has two-stage linear relationships with the change in the excitation wavelength, and the inflection point is at 580 nm (excited at 550 nm). The difference between the emission and excitation wavelengths decreases from 138 to 12 nm, which also shows two-stage linear relationships with the change in the excitation wavelength. It is notable that their PL quantum yields are high, up to 26.6%. Furthermore, we studied the inhibitory effect of as-obtained N-GQDs on bladder cancer cells (UMUC-3); as a result, with the increase of the concentration of N-GQDs, the proliferation of cancer cells was obviously prohibited.

Manometric real-time studies of the mechanochemical synthesis of zeolitic imidazolate frameworks.

We demonstrate a simple method for real-time monitoring of mechanochemical synthesis of metal-organic frameworks, by measuring changes in pressure of gas produced in the reaction. Using this manometric method to monitor the mechanosynthesis of the zeolitic imidazolate framework ZIF-8 from basic zinc carbonate reveals an intriguing feedback mechanism in which the initially formed ZIF-8 reacts with the CO2 byproduct to produce a complex metal carbonate phase, the structure of which is determined directly from powder X-ray diffraction data. We also show that the formation of the carbonate phase may be prevented by addition of excess ligand. The excess ligand can subsequently be removed by sublimation, and reused. This enables not only the synthesis but also the purification, as well as the activation of the MOF to be performed entirely without solvent.

NaCl as a solid solvent to assist the mechanochemical synthesis and post-synthesis of hierarchical porous MOFs with high I2 vapour uptake.

The use of salts as grinding media to assist the mechanosynthesis, and the following one-pot mechanochemical post-synthesis, of hierarchically porous MOFs was carried out efficiently by ball milling. NaCl or KCl were used as a solid solvent to initially pre-grind with 1,3,5-benzenetricarboxylic acid (H3BTC) and copper acetate monhydrate, respectively, for 1 minute, then both mixtures were combined together for a further 20 minutes of grinding, and the resultant mixture was finally washed with ethanol and water to obtain the hierarchically micro-, meso- and macroporous HKUST-1 with a high yield. Moreover, the post-synthesis of these as-obtained hierarchically porous HKUST-1 was easily performed via grinding triethylenediamine (TED) with the above unwashed crude-products for 20 minutes. By adjusting the amount of NaCl and TED added, we simply fabricated the pore- and function-adjustable hierarchically porous HKUST-1. Furthermore, these as-obtained HKUST-1 products showed high performance in the capture of volatile iodine.

Regulation of nonylphenol-induced reproductive toxicity in mouse spermatogonia cells by miR-361-3p.

Nonylphenol (NP) is an environmental chemical that affects apoptosis and male infertility. In our study, we found that a high concentration of NP could down-regulate the expression of microRNA-361-3p (miR-361-3p) in the murine GC-1 spermatogonia cell line and in vivo in murine spermatogonia. Additionally, one direct target of this miR, the 3' untranslated region of Killin (Klln) mRNA, was identified. Klln encodes a transcription factor that directly regulates the expression of Tp73 (transcriptionally active p73), whose encoded protein can up-regulate the expression of Puma (p53 upregulated modulator of apoptosis). Thus, our investigation revealed that the expression of Klln, Tp73, and Puma increased upon NP-dependent down-regulation of miR-361-3p, which eventually leads to apoptosis of spermatogonia.

A new one-dimensional coordination polymer of 5-(1,3-dioxo-4,5,6,7-tetraphenylisoindolin-2-yl)isophthalic acid with manganese.

The coordination polymer catena-poly[[(dimethylformamide-κO)[µ3-5-(1,3-dioxo-4,5,6,7-tetraphenylisoindolin-2-yl)isophthalato-κ(4)O(1),O(1'):O(3):O(3')](methanol-κO)manganese(III)] dimethylformamide monosolvate], {[Mn(C40H23NO6)(CH3OH)(C3H7NO)]·C3H7NO}n, has been synthesized from the reaction of 5-(1,3-dioxo-4,5,6,7-tetraphenylisoindolin-2-yl)isophthalic acid and manganese(II) acetate tetrahydrate in a glass tube at room temperature by solvent diffusion. The Mn(II) centre is hexacoordinated by two O atoms from one chelating carboxylate group, by two O atoms from two monodentate carboxylate groups and by one O atom each from a methanol and a dimethylformamide (DMF) ligand. The single-crystal structure crystallizes in the triclinic space group P\overline{1}. Moreover, the coordination polymer shows one-dimensional 2-connected {0} uninodal chain networks, and free DMF molecules are connected to the chains by O-H···O hydrogen bonds. The thermogravimetric and photoluminescent properties of the compound have also been investigated.

A mechanosynthesized, sequential, cyclic fluorescent probe for mercury and iodide ions in aqueous solutions.

A fluorescent Hg(2+)-selective chemosensor, 2,5-dimethoxybenzaldehyde thiosemicarbazone (1), was quantitatively prepared by grinding 2,5-dimethoxybenzaldehyde and thiosemicarbazide together in a ball mill for 15min. The excitation and emission maxima of compound 1 are 347 and 450nm, respectively. The reaction of this ligand with Hg(2+) was investigated by FT-IR, (1)H NMR, and fluorescence titration. Results show that the composition of the resulting Hg complex 1-Hg is 2:1 1:Hg, and that the S and imino N atoms serve as the binding sites of the ligand to the Hg(2+) ions. Coordination-assisted fluorescence quenching results show that compound 1 exhibits a highly selective fluorescence response to trace amounts of Hg(2+) in water. More importantly, the resulting complex 1-Hg can be used as a turn-on fluorescence probe for I(-) at a detection limit of 8.4×10(-8)M. Thus, compound 1 is a relatively stable, sequential, cyclic fluorescent probe for Hg(2+) and I(-).

Better understanding of mechanochemical reactions: Raman monitoring reveals surprisingly simple 'pseudo-fluid' model for a ball milling reaction.

Quantitative monitoring of a mechanochemical reaction by Raman spectroscopy leads to a surprisingly straightforward second-order kinetic model in which the rate is determined simply by the frequency of reactive collisions between reactant particles.

4-[(2-Carb-oxy-eth-yl)amino]-benzoic acid monohydrate.

In the title compound, C(10)H(11)NO(4)·H(2)O, the carboxyl group is twisted at a dihedral angle of 6.1 (3)° with respect to the benzene ring. In the crystal, the organic mol-ecules are linked by pairs of O-H⋯O hydrogen bonds involving both carboxyl groups, forming zigzag chains propagating along the b-axis direction. The water mol-ecules form [100] chains linked by O-H⋯O hydrogen bonds. The organic mol-ecule and water chains are cross-linked by N-H⋯O(water) and O(water)-H⋯O hydrogen bonds, generating (001) sheets.

[Synthesis, characterization and interaction with ct-DNA of four novel secondary amine complexes].

A novel ligand(L), (N, N'-bis (4-methylbenzyl) ethane-1, 2-diamine), and its transition metal(II) complex, [ML2 (H2O)2]2+ x 2NO3- (M = Cu(II), Co(II, Ni(II), Zn(II)), have been synthesized and characterized by elemental analysis, IR and 1H NMR. The crystal structure of the Cu-L complex was characterized by X-ray single crystal diffraction, and the results showed a regular octahedral structure in which each metal ion is six--coordinated with four nitrogen atoms from two ligands and two oxygen atoms from two water molecules. The interaction of the complex with calf thymus DNA was investigated by UV spectroscopy and fluorescence spectroscopy, and the results suggest that the complex binds to DNA by electrostatic interaction mode. The binding constant(Cu-L, Co-L, Ni-L, Zn-L) was 1.67 x 10(3), 2.5 x 10(3), 1.35 x 10(3) and 9.85 x 10(2), respectively.

A multifunctional 3D ferroelectric and NLO-active porous metal-organic framework.

The tetracarboxylate organic linker and Zn(II) ions assemble into chiral building blocks for a porous metal-organic framework with ferroelectric and second-order nonlinear optical properties.

Bis(µ-N-benzyl-N-tetra-decyl-dithio-carbamato-κS:S')bis-[(N-benzyl-N-tetra-decyl-dithio-carbamato-κS,S')zinc(II)].

In the title compound, [Zn(2)(C(22)H(36)NS(2))(4)], two bidentate dithio-carbamate groups chelate directly to the Zn(II) atoms, whereas the two remaining dithio-carbamate ligands bridge the Zn atoms via a crystallographic inversion centre. The Zn atoms show a strongly distorted tetra-hedral geometry. Adding the long S⋯S distance with the inversion centre being in the middle, the resulting five-coordinate geometry around the Zn atoms can be considered to be between distorted recta-ngular pyramidal and trigonal bipyramidal, with a calculated τ value of 0.31. In this dimer complex, two inversion-related tetra-decyl carbon chains exhibit all-trans conformations, and the other two chains show a cis conformation at the end of the chains.