Remarkable adsorption of hydroquinone as an anion contaminant by using the magnetic supported bimetallic (NiCu-MOF@MAC) nanocomposites in aqueous solutions

Remarkable simultaneous degradation of cephalexin and amoxicillin employing magnetic nano-catalyst supported on bentonite by heterogeneous photo-Fenton

In the present study, the heterogeneous catalysts were synthesized using a facile, economical and environmentally friendly method supported on the natural mineral bentonite to degrade amoxicillin (AMX) and cephalexin (CLX) in the aqueous solutions by employing the photo-Fenton process. The characterization tests including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDAX), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) and vibrating sample magnetometer (VSM) were evaluated to distinguish the physical and chemical properties of the nanocomposites. The adsorption capacity and catalytic performance of the prepared samples for the removal of AMX were investigated in order to compare the presented catalysts, in addition to the structural analysis. Among the fabricated samples, the magnetic nano-catalyst derived from two different sources of iron (ferrous sulfate and ferric nitrate) named FSF-Be was selected as the appropriate catalyst due to its high efficiency for the simultaneous degradation of CLX and AMX. Response surface method (RSM-central composite design (CCD)) was also applied to determine the effect of the operating conditions encompassing pH, initial concentration of contaminants, dosage of catalyst and hydrogen peroxide concentration for the degradation of CLX and AMX, simultaneously. The quadratic mathematical models were developed with high correlation coefficient (0.9454 and 0.9564) for the removal efficiency of AMX and CLX, respectively. Therefore, the maximum degradation efficiency of CLX and AMX was obtained to be about 96.36% and 81.61%, respectively, at the optimal conditions (pH of 3, H2O2 concentration of 12 mM, catalyst dosage of 0.24 g/L and initial concentration of 23 mg/L) in half hour. The ozonation and the combined photo-Fenton/ozone process were investigated. The mineralization analysis illustrated that the photo-Fenton process was able to remove TOC by 73.35%, while only 2.44% of TOC removal was reached by ozonation. The degradation efficiency of CLX and AMX in the photo-Fenton/ozone system within 15 min of reaction was measured as 87.69% and 70.02%, respectively, and 61.9% mineralization was achieved in this system. However, the results showed that the photo-Fenton using FSF-Be was more efficient. The regeneration and reusability of the prepared nanocomposite was also carried out by five consecutive cycles which showed an acceptable performance in the industrial applications. The achievements demonstrated that the removal efficiency of CLX and AMX decreased about 24 and 18% after fifth cycle.

ZIF-67 and Biomass-Derived N, S-Codoped Activated Carbon Composite Derivative for High-Effective Removal of Hydroquinone from Water

Hydroquinone (HQ) in wastewater is of great concern, as it is harmful to human health and threatens the ecological environment. However, the existing adsorbents have low adsorption capacity for HQ. To improve the removal of HQ, N,S-codoped activated carbon-ZIF-67 (NSAC-ZIF-67@C) was synthesized in this study by in situ growth of ZIF-67 on N,S-codoped activated carbon (NSAC) and carbonization. The influence of pH, contact time, and initial concentration on the adsorption behaviors of NSAC-ZIF-67@C on HQ were investigated. Owing to the synergistic effect of abundant active sites and well-developed pore structure, the NSAC-ZIF-67@C achieved a prominent adsorption capacity of 962 mg·g-1 and can still retain high adsorption performance after 5 cycles for HQ, which is superior to that of reported other adsorbents. HQ adsorption follows the pseudo-second-order kinetics model (R2 = 0.99999) and the Freundlich isotherm model. X-ray photoelectron spectroscopy (XPS) analysis before and after adsorption as well as density functional theory (DFT) calculation results showed that pyridinic-N-termini were conducive to the π-π interactions and hydrogen-bonding interactions. Therefore, the adsorption mechanisms of NSAC-ZIF-67@C on HQ involve pore filling, electrostatic attraction, π-π interaction, and hydrogen bonding. This study is expected to provide a reference for designing highly effective adsorbents for wastewater treatment.

Synthesis of novel PANI/PVA-NiCu composite material for efficient removal of organic dyes

The present work aims the synthesis of a novel, low cost, and environmentally friendly PANI/PVA-CuNi composite by chemical oxidative polymerization of aniline monomer and polyvinyl alcohol (PVA) as film matrix; several percentages of copper (Cu) and Nickel (Ni) were used. UV-Visible spectroscopy, FTIR, SEM-EDX, and TGA were used to characterize the nanocomposites. While PANI/PVA-CuNi nanocomposites were investigated in adsorption experiments of methylene blue (MB) under different controlled conditions (time reaction, adsorbent dosage, initial dye concentration, stirring speed, temperature, and pH of the medium) also various kinetic models were employed to evaluate the efficiency of the adsorption. The results revealed that the10 mg of PANI/PVA-Cu₅₀N_i50 and PANI/PVA-Ni composites Catalyst removed (94% and 93% of methylene blue in 180 min respectively at 10^-5 M initial concentration of dye, pH of 13, stirring speed of 150 rpm, the temperature of 301 k. the kinetics data were properly fitted with the pseudo second-order model with a correlation coefficient of 0.98262 and 0.95881 using PANI/PVA-Cu₅₀N_i50 and PANI/PVA-Ni, respectively.

The synthesis and highly effective antibacterial properties of Cu-3, 5-dimethy l-1, 2, 4-triazole metal organic frameworks

The influence of metal ions, the state of metal salt, and ligands on the sterilization ability of (Metalorganic frameworks) MOFs to effectively achieve sterilization has been investigated in this study. Initially, the MOFs were synthesized by elements of Zn, Ag, and Cd for the same periodic and main group of Cu. This illustrated that the atomic structure of Cu was more beneficial for coordinating with ligands. To further induce the maximum amount of Cu²⁺ ions in the Cu-MOFs to achieve the highest sterilization, various Cu-MOFs synthesized by the different valences of Cu, various states of copper salts, and organic ligands were performed, respectively. The results demonstrated that Cu-MOFs synthesized by 3, 5-dimethyl-1, 2, 4-triazole and tetrakis (acetonitrile) copper(I) tetrafluoroborate presented the largest inhibition-zone diameter of 40.17 mm towards Staphylococcus Aureus (S. aureus) under dark conditions. The proposed mechanism of Cu (Ⅱ) in MOFs could significantly cause multiple toxic effects, such as the generation of reactive oxygen species, and lipid peroxidation in S. aureus cells, when the bacteria was anchored by the Cu-MOFs via electrostatic interaction. Finally, the broad antimicrobial properties of Cu-MOFs against Escherichia coli (E. coli), Acinetobacter baumannii (A. baumannii), and S. aureus were demonstrated. In conclusion, the Cu-3, 5-dimethyl-1, 2, 4-triazole MOFs appeared to be potential antibacterial catalysts in the antimicrobial field.