To investigate the adsorption property of H2 and CO2 on the organic ligand of C-MOF-5 (H2BDC) and T-MOF-5 (ZnO-doped H2BDC (ZnO-H2BDC)), Density functional theory (DFT) method was performed. First, the adsorption of ZnO on H2BDC resulted in examining binding energies, the charge transfer, density of states, dipole moments and adsorption geometries were investigated. The binding properties have been calculated and investigated theoretically for ZnO-doped H2BDC in terms of binding energies, band structures, Mulliken charges, and density of states (DOSs). According to obtained results, the H2BDC was strongly doped with ZnO. H2 and CO2 adsorption capacities for ZnO-doped H2BDC are significantly enhanced while there are low adsorption capacities for H2BDC. According to results, at least in the organic ligand of the MOF-5, the highest and lowest adsorption of CO2 (or H2) is attributed to the T-MOF-5 and C-MOF-5 respectively. Our calculations reveal that ZnO-doped H2BDC system (T-MOF-5) has much higher adsorption energy and higher net charge transfer value than pristine H2BDC (C-MOF-5). Also by changing in structure from cubic to tetragonal, the main site for H2 and CO2 adsorption was changed.

HPLC-MS/MS degradation mechanism of Direct Yellow 12 (DY-12) dye using O3 associated with UV was studied. The influent of different conditions such as pH, initial DY-12 dye concentration and reaction time were studied in a batch reactor method. The results revealed that the pH value and DY-12 initial concentration controlled the removal process. The maximum color removal was achieved in alkaline condition (pH 9) as compared to neutral or acidic conditions. The color removal of DY-12 dye followed the first-order kinetics. When UV was applied with ozone simultaneously, the first order rate constant (kd) increased, and the time of dye decolorization shortened to 10 min for 200 ppm dye concentration. These results indicated that the application of UV can reduce the reaction time and dose of ozone. Gas chromatography-mass spectrum and HPLC-MS/MS analyses of the treated synthetic dye solution at the end of the treatment time showed no toxic organic compounds were detected. The COD decreased by more than 85% of the initial COD of the untreated DY-12 dye concentration.

The limited adsorption capacity of natural clays is a crucial and economic issue which confined their applications in industry as cheap adsorbents to remove toxic contaminants from wastewaters. Here, the adsorption capacity of a natural nano bentonite was enhanced by a simple acid and thermal activation and the manufactured nano-adsorbent was characterized by FESEM, BET, FT-IR, and XRD. Effects of pH, temperature, sorbent capacity, and the initial concentration of malachite green were examined. The isotherm behavior of the adsorption system was investigated by the Langmuir and Freundlich isotherm models. Also, the kinetic inspections demonstrated that the adsorption of malachite green matched with the pseudo-second-order kinetic and the obtained thermodynamic parameters H, S, and G showed that the adsorption of malachite green was a spontaneous and endothermic process. The results indicated that the acid-thermal activated nano bentonite, with an enhanced surface area of >220 m2/g, can be depleted as a powerful and low-cost adsorbent to expel malachite green from aqueous solutions.

This research illustrates the effect of miscibility condition between nanofluid and oil on the process efficiency and to achieve this aim four types of fluid including distilled water, ethanol, n-hexane, and gas condensate were used to disperse silica nanoparticles. The prepared nanofluids were injected into a glass micromodel and the oil recovery factor and effective mechanisms were investigated. Results showed that in presence of nanoparticles, the oil recovery factor for miscible base fluids injection increases about 30%. But in immiscible base fluids, nanoparticles enhance the oil recovery factor up to 20% more than the base fluids. So nanoparticles are more efficient in miscible base fluids compared to immiscible ones.

As a step towards the profitable employment of nanoparticles (NPs) in agriculture, effects of chitosan NPs was probed on barley plants under late season drought stress. A factorial experiment was performed based on a randomized complete block design with three replications. The experimental factors included the chitosan NPs concentrations (0 (control), 30, 60 and 90 ppm), application methods (foliar and soil application) and irrigation regimes (well-watered and withholding of irrigation for 15 days after pollination). The barley seeds were separately planted in pots. Then, the NPs were added to them through the soil and foliar application at three stages. The results indicated that using the chitosan NPs, especially 60 and 90 ppm, significantly increased the leaf area (LA), the leaf color (SPAD), the number of grain per spike, the grain yield and the harvest index compared to the control. Also, drought stress significantly decreased the yield and yield components compared to the well-watered plants. In contrast, using the chitosan NPs in plants under drought stress significantly increased the relative water content (RWC), the 1000-grain weight, the grain protein, the proline content, the catalase (CAT) and the superoxide dismutase (SOD) compared to the control. There was no a significant difference between two methods of using NPs in most studied traits. The results highlighted that using the chitosan NPs, especially 60 and 90 ppm, in both irrigation regimes can significantly improve the majority of the studied traits compared to the control and mitigate the harmful effects of drought stress.

Background and objectives: Drug resistance in bacteria is one of the important problems in the antibacterial field. Therefore, new drugs and therapeutic approaches are required to eliminate bacteria using different and novel mechanisms. Among these, the silver nanoparticles have been proposed as a substance with antibacterial properties against gram-positive and gram-negative bacteria. The present study aimed to investigate the effects of silver nanoparticles with a size of less than 20 nm on the genome of Staphylococcus aureus (S. aureus) as a model for gram-positive bacteria. Material and methods: For this purpose, the bacteria were treated at concentrations of 100 and 150 µg/ml nanoparticles and antimicrobial properties of the nanoparticles were investigated in intervals of 2, 4 and 24 hours, then DNA was extracted. RAPD molecular marker was used to investigate the effects of nanoparticles on the genome. In addition, the results of electrophoresis for polymerase chain reaction (PCR) products on agarose gel were analyzed. Results: The present findings demonstrated that silver nanoparticles not only have an inhibitory effect on bacteria but also affect the genomic DNA sequence of this bacterium and change it in different sites. Conclusion: The nanoparticles are antibacterial compounds and can be an appropriate alternative to antibiotics.

Even at low levels, heavy metals are toxic and can damage living things. They do not break down or decompose and tend to build up in plants, animals, and people causing health concerns. Magnetic nanoparticles (MNPs) can be considered as potential adsorbents for the removal of cadmium (Cd2+) from aqueous solutions because of their high surface area and the combined effect of adsorption and separation under external magnetic fields. In this study, a novel sulfur-modified magnetic nanoparticle was applied as an adsorbent for the removal of Cd2+ ions from aqueous solutions. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). The effects of pH, contact time, and initial concentration of Cd2+ on the removal efficiency of it were investigated in batch adsorption experiments. The equilibrium data fitted the Langmuir isotherm model better than the Freundlich isotherm model, and they were well explained in terms of pseudo-second-order kinetics. The maximum monolayer capacity qm and KL the Langmuir constant were calculated from the Langmuir as 5.1867 mg/g and 0.1562 L/mg, respectively.

Nano pore ZSM-5type membranes were prepared on the outer surface of a porous-mullite tube by in situ liquid phase hydrothermal synthesis. The hydrothermal crystallization was carried out under an autogenous pressure, at a static condition and at a temperature of 180°C with tetra propyl ammonium bromide (TPABr) as a template agent. The molar composition of the starting gel of ZSM-5 zeolite membrane was: SiO2/Al2O3=100, Na2O/Al2O3=0.292, H2O/Al2O3=40–65, TPABr/ SiO2=0.02-0.05. The zeolites calcinations were carried out in the air at 530°C, to burn off the template (TPABr) within the zeolites. X-ray diffraction (XRD) patterns of the membranes consisted of peaks corresponding to the support and zeolite. The crystal species were characterized by XRD, and morphology of the supports subjected to crystallization was characterized by scanning electron microscopy (SEM). Performance of Nano-porous ZSM-5 membranes was studied for separation of water–unsymmetrical dimethylhydrazine (UDMH) mixtures using pervaporation (PV). Finally, a comprehensive unsteady-state model was developed for the pervaporation of water-UDMH mixture by COMSOL Multiphysics software version 5.2. The developed model was strongly capable of predicting the effect of various dimensional factors on concentration and velocity distributions within the membrane module. The best ZSM-5 zeolite membranes had a water flux of 2.22 kg/m2.h at 27°C. The best PV selectivity for ZSM-5 membranes was obtained to be 55.