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Our previous studies have shown that the modification of hydroxyapatite with organic phosphonates can greatly improve the adsorption effect of hydroxyapatite on heavy metal ion pollutants. Hydroxyethylydene-1,1-diphosphonate (HEDP) is a widely used multi-purpose chemical agent with the advantage of lower-cost, but the preparation and application of hydroxyapatite composites doped by HEDP have not been reported. Therefore, in the present work, calcium nitrate and diammonium hydrogen phosphate were used as the calcium source and inorganic phosphorus source, respectively. 5%, 10%, 20% and 25% HEDP was added as an organophosphine source in the process of preparing hydroxyapatite （HAP）to obtain inorganic-organic phosphorus hybrid HAP composite materials with different HEDP doping amounts, respectively. XRD characterization showed that when HEDP doping was 20% of total phosphorus, the crystallinity of the resulting composite material was greatly reduced and became amorphous HAP, and the maximum adsorption capacity of the obtained amorphous HAP was 1893.7 mg/g, 239.3 mg/g, 285.4 mg/g, and 339.7 mg/g for Pb2+, Cu2+, Zn2+ and Cd2+, respectively, which was 8.47, 4.25, 3.29, 3.41 times that of the commercial HAP, respectively. Furthermore, Hirshfeld surface analysis specially including fingerprint plot was applied to investigate the interaction between HEDP and HAP, and reduced density gradient (RDG) method was carried out to explore the interaction mechanism of HEDP doping amorphous HAP composite and heavy metal ions. Because of the low price of HEDP, the simple and low-consumption preparation method and the excellent removal effect to various heavy metal pollutants, the inorganic-organic phosphorus hybrid amorphous HEDP-HAP composite material will have broad application prospects in the field of heavy metal pollution control. [Display omitted] • Inorganic-organic phosphorus hybrid amorphous HEDP-HAP was synthesized. • The adsorption capacity of HAP-H-2.0 was much higher than that of HAP. • Hirshfeld surface analysis combined fingerprint plot were applied. • RDG was firstly used to reveal the interaction mechanism among different fragments. [ABSTRACT FROM AUTHOR]

Amino trimethylposphonate(ATMP) functionalized HAP were synthesized with different ATMP addition (0, 5%, 10%, 15%) and the adsorption performance towards Pb2+ and Cd2+ were studied in an aqueous solution. Under the optimum condition, HAP with ATMP addition of 10% (10AT-HAP) displayed the most efficient adsorption performance with the adsorption capacity of 1458.79 mg/g and 321.26 mg/g towards Pb2+ and Cd2+, respectively, which improved 76% and 92% than that of the artificially prepared HAP in the laboratory, respectively. For both heavy metal ions, the adsorption mechanism also included ion exchange and surface complexation, in which the surface complexation played a predominant role. In addition, XRD showed that a new crystal phase was formed after Pb2+ adsorption, while no new phase appeared after Cd2+ adsorption, indicating that the adsorption mechanism of Pb2+ involved dissolution-precipitation. The fitting results of adsorption isotherm and kinetics showed that the adsorption of Pb2+ and Cd2+ on HAP and 10AT-HAP were well fitted by the Langmuir isotherm model and Pseudo-second model. Moreover, Multiwfn wavefunction program based on density functional theory (DFT) was applied to deeply probe and vividly visualize the interaction sites, interaction types, interaction strength and the essence of interactions between HAP and ATMP or ATMP-HAP composite and heavy metal ions. [Display omitted] • The adsorption capacity of 10AT-HAP on Pb2+ and Cd2+ reached 1458.79 and 321.26 mg/g. • The adsorption mechanisms were revealed by experiment and Multiwfn program. • ATMP formed ternary complex with HAP and heavy metal ions. • The oxygen atoms of the phosphate groups of ATMP played a major complexation role. [ABSTRACT FROM AUTHOR]

Benzyldimethylhexadecylammonium chloride (HDBAC) modified montmorillonite was synthesized and the compounds were used for the adsorption of diclofenac sodium (DCF) and ibuprofen (IBU). The adsorption effect was the best when the best dosage of the HDBAC was 1.6 CEC (cation exchange capacity). The adsorption capacity (q e) of H-Mt-1.6 for DCF and IBU was 125.55 mg/g and 81.64 mg/g, respectively. The q e of Ca-Mt for DCF and IBU was 54.02 mg/g and 13.14 mg/g, respectively. H-Mt-1.6 had higher adsorption effect than Ca-Mt. The adsorption process of H-Mt-1.6 on DCF followed the Langmuir adsorption model and the adsorption process of IBU followed the Freundlich adsorption model. The equilibrium could be reached after 120 min. The adsorption process of H-Mt-1.6 on DCF and IBU followed a pseudo-second-order kinetic model. The adsorption on DCF was endothermic, while adsorption on IBU was exothermic. [Display omitted] [ABSTRACT FROM AUTHOR]

In a water solution and with a low reaction temperature of 85 °C, the green preparation of lanthanum-modulated MOF-808 (Zr) was realized, the obtained La-MOF-808 have smaller grain size, larger specific surface area, higher pore volume and larger average pore diameter. When the molar ratio of La: Zr=1:1, 1L-MOF-808 had the best fluoride ion removal performance, and its maximum adsorption capacity for F- reached 101.4 mg/g, which was higher than that of the unmodulated MOF-808 and some other reported fluorine adsorbents. Meanwhile, the regeneration experiment demonstrated that even after five cycles, 1L-MOF-808 retained 73.8 % of its initial adsorption capacity, highlighting its commendable reusability. In addition, when 1L-MOF-808 was applied to actual fluorine-containing wastewater, with the fluoride ion concentration of 25.3 mg/L and an adsorbent dosage of 0.6 g/L, 1L-MOF-808 exhibited excellent resistance to anionic interference (SO 4 2-, Cl-), the concentration of fluoride ions in effluent was lower than 10 mg/L, meeting the stipulations of fluoride ion discharge outlined in GB39371–2020. Further adsorption mechanism investigation revealed that 1L-MOF-808's affinity for F- was attributed to electrostatic interaction and ligand exchange. Overall, the as-synthesized 1L-MOF-808 not only presents an environmentally friendly approach to producing MOF materials without organic solvents but also develops a new strategy for the design of high-performance adsorbent for effectively removing fluoride ions from wastewater. [Display omitted] • La-modulated MOF-808(Zr) was prepared for the first time and used to remove F-. • The adsorption mechanism involved electrostatic interaction and ligand exchange. • The maximum adsorption of 1LMOF-808 for F- was 101.4 mg/g. • La modulating provided additional active sites and improved the adsorption effect. [ABSTRACT FROM AUTHOR]

The release of benzothiazoles into the environment has been reported to affect the ecological environment and human health, so it makes significant sense to remove benzothiazoles from aquatic environment. They are poorly eliminated by conventional wastewater treatment. A few studies have shown that benzothiazoles are difficult to bioaccumulate or sorb to particles, therefore, it is very meaningful to study their efficient adsorption. In this work, the novel combined modified montmorillonite with hydroxyl iron pillared and cationic panthenol intercalation (Fe-CPMMt) was firstly prepared and evaluated its removal effect for emerging contaminant-benzothiazole. The batch adsorption experiments showed that the maximum adsorption capacity of Fe-CPMMt for benzothiazole was 69.72 mg/g, while that of the original acidified sodium montmorillonite, alone hydroxyl iron pillared montmorillonite (Fe-AMt), alone cationic panthenol intercalated montmorillonite were 11.39 mg/g, 43.68 mg/g and 38.18 mg/g, respectively. The adsorption process for benzothiazole on Fe-CPMMt-1.0 conformed well to Langmuir isotherm adsorption model and the pseudo-second-order kinetic model, and was spontaneous and endothermic. Moreover, combining with the Zeta potential values of Fe-AMt and Fe-CPMMt-1.0, and with the help of Multiwfn wave function program based on density functional theory, the electrostatic attraction and coordination between Fe-AMt and benzothiazole, while the electrostatic interaction, hydrophobic partitioning, complexation, p-π/π, OH/π and CH/π interactions were verified between Fe-CPMMt and benzothiazole pollutant. The work confirmed that the novel combined modified montmorillonite with hydroxyl iron pillared and cationic panthenol intercalation has a better adsorption effect on benzothiazole. Combined with the insight into the adsorption mechanism from the atomic level, it might provide novel information for exploring a new more efficient inorganic-organic combined modified montmorillonite adsorbent for removing stubborn organic contaminants in water. [Display omitted] [ABSTRACT FROM AUTHOR]

Many studies have proved that montmorillonite (Mt) has good adsorption properties for some antibiotic pharmaceuticals, but the detailed research on the microscopic sorption mechanism is very limited from the atomic level. In the present work, Mt was chosen as an adsorbent for common emerging contaminant-ciprofloxacin (CIP) to investigate the essence of the interaction between Mt and different CIP species at different pH. X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR) characterization after adsorption under different pH were utilized to explore the difference of adsorption mechanism with the changed pH. Especially outstanding, for the first time, Molecular dynamics simulation (MD) was carried out to investigate the arrangement and dynamic behavior of cationic CIP in the interlayer of Mt, Multiwfn wave function analysis program was performed to quantitatively analyze the molecular surface electrostatic potential (ESP) distribution of different CIP species to evaluate the electrostatic interaction. Furthermore, for the first time, Hirshfeld surface analysis and independent gradient model (IGM) analysis were applied to probe and visualize the interaction sits between Mt and CIP zwitterion(CIP+/−) or CIP anion (CIP-), which can reveal the adsorption mechanism of Mt for CIP+/− and CIP- from the atomic level microscopic perspective. [ABSTRACT FROM AUTHOR]

In recent years, metal-organic framework derivatives have been regarded as materials with great potential for water treatment applications. In this study, we employed a polyvinylpyrrolidone (PVP)-assisted copper-cobalt bimetallic zeolitic imidazole framework (ZIF) as a template to rationally design nanosheet-like mixed metal oxide embedded nitrogen-doped carbon (CuCoO-PC). CuCoO-PC exhibited excellent degradation potential towards metronidazole (MNZ) and achieved almost complete degradation within 7 min through the activation of peroxymonosulfate (PMS). Importantly, the introduction of copper into CuCoO-PC established strong interactions between copper and cobalt, accelerating the activation performance of PMS. Furthermore, PVP, rich in nitrogen atoms, formed strong coordination interactions with ZIF precursors, which effectively protected the morphological stability of ZIF at high temperature, preventing collapse and aggregation. Meanwhile, the formation of nitrogen-doped carbon networks provides a pathway for the generation of non-radical. The study found that CuCoO-PC continuously activated PMS, generating various reactive oxygen species (ROS), among which SO 4 •- and 1O 2 played decisive roles. By calculating the HOMO, LUMO, and Fukui functions, we identified the reactive sites of MNZ and proposed possible degradation pathways. CuCoO-PC demonstrated excellent catalytic performance, reduced toxicity of intermediate products, and good reusability, all of which highlight its enormous potential in practical applications. [Display omitted] • CuCoO-PC composites are prepared using PVP to enrich the nitrogen content. • CuCoO-PC/PMS system exhibits prominent catalytic performance for MNZ removal. • SO 4 •- and 1O 2 was the main active substance involved in the MNZ degradation. • CuCoO-PC was stable and effective in multiple cycles of MNZ degradation efficiency. • The most reactive site on MNZ molecule was predicted by DFT calculation. [ABSTRACT FROM AUTHOR]

Biologically treated coking wastewater (BTCW) frequently contains many kinds of refractory and toxic organic pollutants, which is far from meeting the discharge standard of GB16171–2012. In the present work, the peroxymonosulfate (PMS) activation processes via Cu-doped LaFeO 3 (LFC) prepared with Bis (hexamethylene triaminepenta(methylenephosphonic acid) (BHMTMP) as the complexing agent was first utilized to degrade BTCW. The degradation reaction rate constant (k obs) of LaFe 0.5 Cu 0.5 O 3 (LFC5)/PMS for COD Cr and NH 3 -N was 3.65 times and 3.63 times for LFO (LaFeO 3)/PMS. Moreover, the k obs of LFC5/PMS system prepared using BHMTMP as the complexing agent surpassed that of the LFCC/PMS system prepared with citric acid (CA) as the complexing agent, and the former was 2.3 times and 1.8 times greater than that of the latter for the removal of COD Cr and NH 3 -N, respectively. The leaching of Cu and Fe of LFC5 was much less than that of LFCC, the strong chelation performance of BHMTMP with various metal ions can greatly reduce the leaching of metal ions and improve the stability of the catalyst. Hydroxyl radicals, sulfate radicals, and singlet oxygen were generated in the LFC5/PMS system, with singlet oxygen playing a dominant role. HPLC, UV absorption spectra, and 3D-EEM fluorescence spectra were used to analyze pollutant components in BTCW before and after degradation, demonstrating the effective removal of certain residual contaminants. In addition, the degradation process of BTCW was modeled using a 3-factor-3-level Response Surface Methodology (RSM) model. RSM model fitted the true experimental results well. This research offers a new approach for the comprehensive treatment of BTCW to meet standard discharge requirements and promote a more cost-effective operating process. [Display omitted] [ABSTRACT FROM AUTHOR]

Mg/Al layered double hydroxides (LDH) intercalated by Ethylenediamine-tetramethylene phosphonic acid (EDTMP) was synthesized to remove Pb2+ and Cd2+ from aqueous solutions, and the intercalation of EDTMP enhanced the adsorption capacity of LDH for both of the heavy metal ions. At a pH of 6.5 and with an optimal intercalation amount of 20% EDTMP, the 20EDT-LDH composite demonstrated an adsorption capacity of 249.82 mg/g for Pb2+ and 160.85 mg/g for Cd2+, resulting in a removal rate of 64.34% for Pb2+ and 99.93% for Cd2+. 20EDT-LDH showed great resistance to interference ions, as it maintained satisfying adsorption performance when a much higher concentration of K+ and Ca2+ than that of Pb2+ and Cd2+ were present, with the adsorption capacity of Pb2+ and Cd2+ being greater than 83.4% and 66.3% of the maximum adsorption capacity, respectively. This was due to the strong chelation ability of EDTMP with Pb2+ and Cd2+, as confirmed by characterizations after adsorption of 20EDT-LDH with Pb2+ and Cd2+. Moreover, the affinity between EDTMP and LDH was revealed via Independent Gradient Model based on the Hirshfeld partition of molecular density (IGMH) and Hirshfeld surface analysis. [Display omitted] • LDH with EDTMP was firstly prepared and separate Pb2+ and Cd2+. • The adsorption capacity of 20EDT-LDH greatly improved than that of LDH. • IGMH and Hirshfeld surface was executed to visualize the interaction. • The coordination mechanism between EDTMP and Pb2+ or Cd2+ was revealed. • The recycle of 20EDT-LDH was good. [ABSTRACT FROM AUTHOR]

Passive inhalation of chloramphenicol (CAP) and untimely intake of riboflavin (RF) can cause damage to physical function. The quantitative detection of these two substances is conducive to monitoring human health, while a method for detecting these two substances at the same time has not been reported. In this paper, an efficient sensor for simultaneous detection of RF and CAP by culturing molybdenum disulfide nanosheets on nitrogen-doped seaweed-derived porous carbon (N-PC@MoS 2) has been prepared. The introduction of N-PC improved the conductivity of the composite and reduced the agglomeration of the MoS 2 nanosheets to guarantee the exposure of more catalytic sites. Consequently, the composite material represented improved electrochemical performance and the ideal simultaneous detection of CAP and RF was achieved in the linear range of 10 ~ 500 μM. In addition, the sensor has been proven to have sufficient stability and anti-interference, which makes it potential in practical applications. This work also noticed the reaction sites and activities of RF and CAP prediction through orbit-weighted dual descriptor, providing a direction for an in-depth understanding of the reaction mechanism of target molecules at the electrode interface. [Display omitted] [ABSTRACT FROM AUTHOR]