Search

In this work, a convenient multi‐component reaction towards the synthesis of spiropyran derivatives catalyzed was described using SBA‐15/(CH2)3N(CH2PO3H2)(CH2)2‐N(CH2PO3H2)2 as a novel efficient, recyclable and nanostructured catalyst in water under reflux condition. The main advantages of the offered methodology are notable yields, short reaction times and the reusability of the catalyst. This catalyst was also tested in large scale to investigate it for using in industrial applications which had remarkable results. Multi‐component synthesis of spiropyran derivatives was carried out using SBA‐15/(CH2)3N(CH2PO3H2)(CH2)2‐N(CH2PO3H2)2 as a new, efficient and nanostructured catalyst in water under reflux condition. [ABSTRACT FROM AUTHOR]

Herein novel crab-like biological-based glycoluril with sulfonic acid tags, namely glycoluril tetrakis(butane-1-sulfonic acid) (GTBSA), was prepared in nano-size form and fully characterized via several techniques, such as 1H and 13C NMR, Fourier transform infrared spectroscopy (FT-IR), CHNS analysis, mass spectroscopy, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric analysis (DTG), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is proved that this novel nanostructured catalyst is an efficient catalyst for the synthesis of novel spiropyrans via the one-pot multi-component condensation of isatine, naphthalene-2,3-diol or 2,5-dihydroxycyclohexa-2,5-diene-1,4-dione, and malononitrile or 1,3-dicarbonyl compounds in refluxing water. The mild reaction conditions, easy work-up, good to excellent yields and reusability of the catalyst are the major advantages of the described procedure. Results from DPPH radical scavenging assays showed that the synthesized compounds have eminent antioxidant efficacies (IC50 : 0.16 ± 0.01 to 0.55 ± 0.02 mg mL−1). Moreover, the in vitro antibacterial activities of the compounds were assessed against 4 Gram-positive and Gram-negative bacterial strains via a disc diffusion method. The results showed that compounds 2S and 3S possess high suitability for E. coli growth inhibition, comparable to the positive control gentamicin. [ABSTRACT FROM AUTHOR]

A convenient method for the synthesis of pyrido[2,3‐d]pyrimidines by using the novel nano‐magnetic silica‐bonded S‐sulfonic acid[Fe3O4@SiO2@(CH2)3S–SO3H] as an efficient and recyclable catalyst under neat conditions is described. The major advantages of the present methodology are high yield, short reaction time, and reusability of the catalyst. Furthermore, the nano‐magnetic silica‐bonded S‐sulfonic acid was fully characterized by using various techniques such as FT‐IR, TG/DTG, DTA, EDX, μXRF, XRD, HRTEM, SEM, SEM elemental mapping, XPS, and N2 physisorption. The results obtained from this research support the idea of rational design, synthesis, and applications of task‐specific and reusable catalysts for the preparation of various polynitrogenated heterocyclic compounds containing 1,4‐dihydropyridine moieties. [ABSTRACT FROM AUTHOR]

• SiO2-incorporated Ti/IrO2-Ta2O5 was applied as the anode. • Metronidazole degradation on a novel Ti/ IrO2-Ta2O5-SiO2 anode was evaluated. • The degradation of Metronidazole was optimized by response surface methodology. • Decolorization efficiency of 98.54% and TOC removal of 78.9% were achieved. • Five organic intermediates were identified. The treatment of Metronidazole (MTZ) as a persistent pharmaceutical waste in the water is a significant challenge. To reduce the adverse effect of MTZ in water, we tested a novel SiO 2 -incorporated MMO-Ti/IrO 2 -Ta 2 O 5 electrode via the electrochemical oxidation (EO) method. The electrode was characterized by scanning electron microscopy, energy dispersive spectrum, atomic force microscopy, and cyclic voltammetry analyses. Structural characterization results were represented high resistance, compact surface, and better electrocatalytic properties for Ti/IrO 2 -Ta 2 O 5 -SiO 2 electrode. The influence of critical operational parameters, including applied current density, initial pH, initial concentration of MTZ, and electrolysis time, was detected on electrocatalytic removal efficiency. It was recognized that the high electrocatalytic power of SiO 2 -incorporated MMO-Ti/IrO 2 -Ta 2 O 5 electrode gives a high amount of •OH during the removal process. At optimum conditions (pH = 7, J = 200 mA/cm2, [MTZ] 0 = 40 mg/L, t = 80 min), 98.76% MTZ removal efficiency was achieved. Besides, comparison analysis was performed with SiO 2 -incorporated MMO-Ti/IrO 2 -Ta 2 O 5 electrode and Ti/IrO 2 -Ta 2 O 5 , so results point out the higher total organic carbon removal of about 78.90% and 54.30% with SiO 2 -incorporated MMO-Ti/IrO 2 -Ta 2 O 5 than Ti/IrO 2 -Ta 2 O 5 , respectively. Furthermore, MTZ removal intermediates formed during the electrocatalytic oxidation process were identified by the gas chromatography–mass spectrometry technique. [Display omitted] [ABSTRACT FROM AUTHOR]

Improvement of methods for the synthesis of high-energetic scaffolds such as 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazaisowurtzitane or 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo [5.5.0.05,903,11]dodecane (TEX) is in demand because these materials may be used as high explosives. Herein, we demonstrate that the ionic liquid 3-methyl-1-sulfonic acid imidazolium nitrate ([Msim]NO3) is an efficient reagent for the synthesis of TEX via nitration of 1,4-diformyl- 2,3,5,6-tetrahydroxypiperazine (DFTHP) with high efficiency and short reaction time and under mild conditions. [ABSTRACT FROM AUTHOR]

Nowadays, the removal of pharmaceutical contaminants from water resources and wastewater is of great importance due to environmental and health issues. Over the decades, various methods have been reported to remove pollutants from wastewater. Among the developed methods, advanced oxidation processes (AOPs) have received significant attention from researchers. In this study, we report the one-pot synthesis of graphene hydrogel-metal (GH-M, M: Co, Ni, Cu) nanocomposites via the combination of polyol and hydrothermal methods. The structure of the resulting nanocomposites was examined by transmission electron microscopy (TEM), inductively coupled plasma-mass spectroscopy (ICP-MS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy methods. Afterward, as-prepared GH-Cu, GH-Co, and GH-Ni nanocomposites were used to prepare cathodes for the electro-Fenton (EF) process to remove rifampicin (RIF) from polluted water. The effect of operational parameters, including current density (mA/cm2), initial pH, initial RIF concentration (mg/L), and process time (min) was investigated via response surface methodology (RSM). The optimal values for current density, pH, initial RIF concentration, and process time using GH-Ni as cathode were 30 mA/cm2, 5, 30 mg/L, and 90 min, respectively. The results at optimal values showed that the maximum RIF removal efficiency for GH-Cu, GH-Co, and GH-Ni cathodes was 90.47, 92.60, and 93.69%, respectively. Brunauer Emmett Teller (BET), atomic force microscopy (AFM), energy-dispersive X-ray (EDX), and cyclic voltammetry (CV) analyses were performed to investigate the performance of the cathodes for the RIF removal. Finally, total organic carbon (TOC), gas chromatography–mass spectrometry (GC-MS), and atomic absorption spectroscopy (AAS) analyses were performed for further investigation of the RIF removal from polluted water. The results claimed that one-pot synthesized GH-M cathodes can effectively remove RIF from polluted water through EF process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Graphene quantum dots were synthesized via facile pyrolysis of citric acid. • Gr/CS/GQDs cathode was fabricated via ultrasonic and sol–gel methods. • TCL removal was investigated via the EF method through RSM. • The maximum RE% of 92.98% was achieved for TCL via Gr/CS/GQDs cathode. • The Gr/CS/GQDs cathode showed excellent performance and reusability after various runs. In this research, graphene quantum dots (GQDs) was synthesized via the facile pyrolysis method. The properties of the prepared GQDs were examined by high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS), photoluminescence (PL), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet–visible (UV–Vis) methods. Afterward, the graphite/chitosan/graphene quantum dots (Gr/CS/GQDs) nanocomposite was prepared and used as a cathode electrode in electro-Fenton (EF) process to study the tetracycline (TCL) removal from the aqueous solution. The effect of operational parameters in EF, including current density (mA/cm2), initial pH, initial TCL concentration (mg/L), and process time (min) on the TCL removal efficiency, was investigated via response surface methodology (RSM). The results showed that the optimal values for current density, pH, initial TCL concentration, and process time were 60 mA/cm2, 5, 30 mg/L, and 150 min, respectively. Maximum TCL removal efficiency was 92.98%. FT-IR, XRD, Raman spectroscopy, atomic force microscopy (AFM), SEM, mapping, energy dispersive X-Ray (EDX), Brunauer Emmett Teller (BET), and cyclic voltammetry (CV) analyses were performed to investigate the Gr/CS/GQDs cathode. Finally, gas chromatography–mass spectrometry (GC-MS), total organic carbon (TOC), and atomic absorption spectroscopy (AAS) analyses were performed and the reusability of the Gr/CS/GQDs cathode was investigated. [ABSTRACT FROM AUTHOR]

• The MIL-101(Cr)-N(PC)@PdCl 2 as a metal-organic framework with porous and high surface area was synthesized and characterized. • A new selective nitration by using MIL-101(Cr)-N(PC)@PdCl 2 /sodium nitrite was introduced. • Mildness, green, facile workup, high yields, short reaction times, are major advantages of described method. A new selective nitration methodology is reported in which MOFs/sodium nitrite is used. A wide range of compounds such as boronic acids, aryl halides, aryl trifluoromethanesulfonate and aroyl chlorides were nitrated in the presence of a catalytic amount of palladium (Pd) embedded into MIL-101(Cr)-NH 2 as a porous metal-organic frameworks (MOFs). The described method provides a beneficial and convenient strategy for chemo and homoselective ipso-nitration reaction. In contrast to the previously reported methodologies, acid nitric (HNO 3) was not used in the course of the nitration reaction. The presented method was applied for the ipso-nitration of a broad range of compounds (47 samples) under mild conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

In the last decade, Metal-organic frameworks (MOFs) were utilized to uptake pollutants from water due to their distinctive features such as tunability, high surface area, and ease of functionalization. In the present research, a novel amine-functionalized MIL-DETA-n (n ​= ​DETA molar ratio) was prepared through the impregnation method using diethylenetriamine (DETA) and MIL-53 (Fe) and characterized using SEM, EDX, XRD, FT-IR, and BET analyses. The MIL-DETA-n was used to adsorb As(V) from aqueous media, and adsorption capacity was reached 137.5 ​mg/g. DETA functionalization of MIL-53(Fe) decreased Fe leaching and kept Fe concentration below 0.3 ​mg/L as the maximum contaminant level. The effect of different parameters such as temperature, pH, trace arsenate concentrations, co-existing ions, and reusability was studied. The kinetic and thermodynamic studies demonstrated that adsorption follows the pseudo-second-order model, and the equilibrium data fits with the Langmuir isotherm. For the first time, the MIL-DETA-n was successfully employed to remove arsenic from surfaces and groundwater. [Display omitted] • Successfully amine-functionalization of MIL-53(Fe) using diethylenetriamine to prepare MIL-DETA. • High performance of MIL-DETA adsorbent to uptake As(V). • Reaching arsenate removal capacity to 137.5 ​mg/g. • Decrease in Fe leaching after amine-functionalization. • The superior efficiency of MIL-DETA in polluted surfaces and groundwater. [ABSTRACT FROM AUTHOR]

Nowadays, the entry of organic compounds into water resources is one of the leading global concerns due to the lack of water resources and rapid population growth. In this research, anodic oxidation (AO) method was used to remove 5-fluorouracil (5-FU) from aqueous solutions via Ni/RuO 2 and Ti/IrO 2 –TiO 2 –RuO 2 electrodes as cathode and anode, respectively. For this purpose, the characterization analysis of the electrodes, including X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, and atomic force microscopy were performed. The electrochemical performance of the anode was investigated via cyclic voltammetry analysis. Then, the effect of operational variables, including applied current (mA), initial pH of the solution, initial 5-FU concentration (mg/L), and process time (min) on the 5-FU removal efficiency under the AO process was evaluated via artificial neural network (ANN) modeling. The results revealed that the maximum 5-FU removal efficiency was 96.96%. The applied current intensity, pH, initial 5-FU concentration, and process time were 300 mA, 5, 20 mg/L, and 140 min, respectively. Moreover, the investigation of 5-FU removal by-products and mineralization efficiency of the AO process was carried out via gas chromatography-mass spectrometry and total organic carbon analysis, respectively. The total organic carbon mineralization efficiency was 84.80% after 6 h of reaction time. The reusability and stability of the Ti/IrO 2 –TiO 2 –RuO 2 anode on 5-FU removal efficiency were measured and showed an approximately 5% decay in 5-FU removal efficiency after eight consecutive runs. The overall results and analysis confirmed this method is capable of removing 5-FU through Ti/IrO 2 –TiO 2 –RuO 2 anode and Ni/RuO 2 cathode from aqueous medium. [Display omitted] • Anodic oxidation was applied to investigate 5-fluorouracil (5-FU) removal. • 5-FU removal efficiency was predicted by artificial neural network modeling. • 96.96% of 5-FU removal was achieved via Ti/Ir 0·2 Ti 0·6 Ru 0·2 O 2 and Ni/RuO 2 electrodes. • Anodic oxidation process possible by-products was identified via GC-MS. • The electrodes showed great performance of reusability after eight runs. [ABSTRACT FROM AUTHOR]

In this work, the fluoxetine (FLX) removal has been studied via the anodic oxidation (AO) process. Anode electrodes were Ti/RuO 2 , Ti/RuO 2 –IrO 2 , and Ti/RuO 2 –IrO 2 –SnO 2 , and cathode electrodes were graphite and carbon nanotubes (CNTs). The performances of electrodes were compared in terms of FLX removal efficiency. As a result, Ti/RuO 2 –IrO 2 –SnO 2 and CNTs were the optimal anode and cathode, respectively. The properties of the optimal electrodes were investigated using scanning electron microscopy, atomic force microscopy and X-ray diffraction spectroscopy. Cyclic voltammetry analysis was performed to study the electrochemical behavior of electrodes. The effect of current intensity (mA), initial pH, initial FLX concentration (mg/L) and process time (min) on the FLX removal efficiency was investigated and the response surface methodology was applied for the optimization of the AO process. The results showed that at current intensity, pH, initial FLX concentration and process time of 500 mA, 6, 25 mg/L and 160 min, maximum FLX removal efficiency was observed, which was 96.25%. Gas Chromatography-Mass Spectrometry (GC-MS), and total organic carbon (TOC) analysis was determined to evaluate the intermediates, and mineralization efficiency. The TOC removal efficiency was reached 81.51% after 6 h under optimal experimental conditions, indicating the successful removal of the FLX. [ABSTRACT FROM AUTHOR]

In recent years, Metal-organic frameworks (MOFs) have received significant attention to adsorb arsenic from aqueous media. In this study, magnetic Fe 3 O 4 @SiO 2 -MIL-53(Fe) was prepared and characterized by XRD, SEM, EDX, FTIR, VSM, and BET techniques. The synthesized Fe 3 O 4 @SiO 2 -MIL-53(Fe) was successfully applied to remove arsenate with a maximum adsorption capacity of 70.1 mg/g. The adsorbent capability was tested in different pH, co-existing ions, and trace arsenate concentrations, and their particles were easily separated from the solution by an external magnetic field. Adsorption and VSM tests showed that the adsorbent capacity and magnetic properties were preserved after four cycles. The adsorption process obeyed the pseudo-second-order model and the experimental data well fitted with Langmuir monolayer isotherm. Immobilization of Fe 3 O 4 @SiO 2 nanoparticles into the MIL-53(Fe) structure was reduced iron ions leaching to the solution. For the first time, the Fe 3 O 4 @SiO 2 -MIL-53(Fe) composite was successfully used to remove arsenic from contaminated surfaces and groundwater. [Display omitted] • Successfully synthesis of Fe 3 O 4 @SiO 2 -Mil-53(Fe) composite. • High performance of composite in As(V) removal. • Application of composite in arsenic removal from contaminated surfaces and groundwater for the first time. • Reduction in iron leaching to the solution. • The efficiency of composite to uptake trace As(V) contamination. [ABSTRACT FROM AUTHOR]

In this study, the heterogeneous electro-Fenton method was used to remove Paclitaxel as an antineoplastic medicine. The cathode based on three-dimensional graphene (3DG) was applied as a gas diffusion electrode. The potential of five eco-friendly and recyclable iron minerals derived from nature (Magnetite, Siderite, Hematite, Limonite, and Pyrite) was investigated. Among the applied iron minerals, Pyrite showed the best, and Magnetite and Siderite showed good catalytic activity at pH 3.0. The current intensity of 300 mA, pH i 7.0, Paclitaxel concentration of 3 mg L−1, amount of Pyrite 4.5 g L−1, and time of 120 min was the optimum condition of the process with the removal efficiency of 99.13% in the presence of Pyrite. Repeating the experiments eight times revealed the reusability of the prepared 3DG as a cathode. Also, using radical scavengers indicated the principal role of the hydroxyl radicals (OH) in the treatment process. Analysis of total organic carbon reached 77.64% mineralization of 3 mg L−1 Paclitaxel at 360 min. Finally, ten by-products of small molecules were identified by gas chromatography-mass spectrometry device. [Display omitted] • Gas diffusion electrode was applied for in situ electro-generation and activation of H 2 O 2. • Green catalysts of natural iron minerals were applied. • Pyrite demonstrated a wide pH application range. • Modeling of the operational condition was done by artificial neural network. • GC-MS was applied to determine by-products of mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of iron(II) doped carbonaceous aerogel (FCA) as a three-dimensional cathode electrode for electro-Fenton (EF) system. • Degradation of ceftazidime using FCA cathode in EF process. • Optimization of the operational condition by response surface methodology. • Identification of the produced intermediates through the ceftazidime degradation. • Developing a safe, environmentally friendly, and cost-effective method by using FCA and EF process. In the present study, the electro-Fenton (EF) process has been used to remove ceftazidime (CAZ) from an aqueous solution. In the first part of this study, the iron(II) doped carbonaceous aerogel (denote as FCA) as a three-dimensional cathode was synthesized as a cathode electrode. For this purpose, resorcinol–formaldehyde polymers containing iron(II) salt were prepared by sol–gel method and after drying by ambient drying method, the resulting polymer was finally carbonized in a furnace with inert nitrogen medium at 800 °C and the resulting composite properties examined by Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray, Brunaur-Emmett-Teller, X-ray Diffraction, Fourier Transform Infrared Spectroscopy, and cyclic voltammetry analyses. In the last part of this study, the prepared carbonaceous aerogel was employed as a cathode electrode in the EF system to remove CAZ from an aqueous medium. The influence of key factors such as applied current (mA), initial pH of the solution, initial CAZ concentration (mg/L), and process time (min) on the CAZ removal efficiency (RE (%)) under the EF process was assessed. The mineralization current efficiency (MCE) was found as 60.66% in 200 min. Response surface methodology (RSM) was used to optimize the process. The results showed that the optimal values for the variables of applied current intensity, pH, initial CAZ concentration, and process time were 400 mA, 4, 40 mg/L, and 110 min, respectively. The intermediates of CAZ removal were identified by gas chromatography-mass spectrometry analysis. Moreover, the possible removal mechanism of CAZ was proposed. The reusability and stability of the FCA cathode was assessed and revealed an approximately 4% decline in CAZ removal efficiency after eight consecutive cycles. The amount of organic carbon degraded by this process was investigated by chemical oxygen demand test and it was 99% after 200 min of reaction time. [ABSTRACT FROM AUTHOR]

• Fabrication of NiO NPs through a solvothermal method in the presence of DES. • NPs act as a commendable catalyst for sonophotocatalytic degradation of Phenazopyridine. • Sonophotocatalytic system shows superiority over the individual US or UV. NiO nano-photocatalysts have demonstrated good photocatalytic performance for the degradation of wastewater pollutants. The purpose of this study is to investigate the effect of Deep Eutectic Solvent (DES) on the structure, morphology, and photocatalytic activity of synthesized nanoparticles. Herein, mesoporous NiO nanoparticles (NPs) were synthesized in the presence of DES by a solvothermal method. The synthesized nanostructures were characterized using XRD (X-ray diffraction), BET (Brunauer-Emmett-Teller), and HRTEM/TEM (High-Resolution Transmission Electron Microscopy) to evaluate their crystallinity, size, composition, and morphology. The analysis shows that the NiO NPs synthesized in DES have high porosity and specific surface area which results in better photocatalytic performance for the degradation of organic pollutants. NiO NPs can remove 90 %, 81 %, and 0 % of organic model pollutant phenazopyridine (PhP) during sonophotocatalytic, photocatalytic, and sonocatalytic processes, respectively. The simultaneous use of ultrasonic radiation, UV lamp, and prepared catalyst in the sonophotocatalytic reaction had a positive synergistic effect of about 28.36 %. The mechanism of the sonophotocatalytic process was studied through the addition of scavengers and enhancers. Scavengers like formic acid (14 %), isopropanol (15 %), and sodium bicarbonate (76 %) significantly declined removal efficiency. Conversely, the presence of potassium persulfate (97 %) as an enhancer improved degradation efficiency by 7 %. The degradation of PhP exhibits pseudo-first-order kinetics across all experiments (R2 > 0.97). The reusability test shows a negligible decline in sonophotocatalytic performance after four consecutive uses. This feature improves the application of nano-photocatalysts in the industrial field, like wastewater treatment. [ABSTRACT FROM AUTHOR]

Some of the important goals in the development of the electro-Fenton (EF) process are to increase the performance of the electrodes while reducing their size as an alternative for expensive electrodes, expanding the active pH range, and also generating reactive oxygen species (ROSs) directly without using other homo/heterogeneous catalysts. This work modified graphite felt (GF) using a rapid and in-situ synthesis with Co/Zn doped mixed-metal ZIF. After calcination, various physicochemical analyses, including XRD, SEM, and XPS, confirmed that a carbonic material doped with mixed-oxide CoO/Co 2 O 3 is embedded on the surface of GF fibers. LSV analysis showed that the modification significantly improved the electrode activity for O 2 reduction. The modified CoZnCal-GF electrode showed good performance and higher kinetics in the EF process. It removed 87% of rifampin (RIF) in a short period of 30 min without any homo/heterogeneous catalysts. The selected conditions for this process were 1.0 V, 40 mg/L, and 5.6 for applied voltage, initial RIF concentration, and pH, respectively. The non-radical species 1O 2 showed the most important role in removing RIF. LC-MS analysis was performed, and while confirming the complete removal of RIF, it was used to investigate the degradation pathway and identify the produced intermediates. [Display omitted] [ABSTRACT FROM AUTHOR]

• Various metal and metal oxide nanoparticles were synthesized. • Catalytic properties of the synthesized nanoparticles were investigated. • Gold nanorods successfully catalyze permanganate-fluorescein CL system. • Silver nanoprisms successfully catalyze the permanganate-bromide CL system. Nanomaterials have attracted a great deal of attention due to their specific chemical and physical properties. In the present study, the effect of some nanosized materials and structures on the permanganate chemiluminescence (CL) systems has been investigated and their mechanism of action on the respective reactions has been discussed. In the first part, various nanoparticles were synthesized including: the gold nanorods with the aspect ratios of 2.4, 3 and 3.7, silver nanoparticles with dimensions of 20 and 32 nm, gold nanoparticles with sizes of 10, 18, 32 and 43 nm, silver nanoprisms, FeOOH, Fe 2 O 3 and Fe 3 O 4 nanoparticles. These nanoparticles were characterized via X-ray diffraction, scanning electron microscopy and transmission electron microscopy analysis. In the second part of the research, the catalytic properties of these nanoparticles on the permanganate-fluorescein and permanganate-bromide systems were studied. The results showed that the silver nanoprisms had a significant enhancing effect on the system. Then, the optimum conditions for the CL permanganate-bromide silver reaction were investigated. [Display omitted] [ABSTRACT FROM AUTHOR]

Herein, we have presented a new insight for the synthesis of a hybrid heterogeneous catalyst. For this purpose, phosphonic acid tagged carbon quantum dots of CQDs-N(CH2PO3H2)2 encapsulated and assembled in channels of SBA-15 using a post-modification strategy. The mesoporous catalyst of functionalized carbon quantum dots (CQDs) was characterized by several techniques. CQDs-N(CH2PO3H2)2/SBA-15 as an excellent catalyst was applied for the preparation of novel pyrazolo[4′,3′:5,6]pyrido[2,3-d]pyrimidine derivatives by using pyrazole, barbituric acid and indole moieties at 100 °C under the solvent-free condition. The present work shows that a significant increase in the catalytic activity can be achieved by a rational design of mesoporous SBA-15 modified with CQDs for the synthesis of biological active candidates. The synthesized compounds did not convert to their corresponding pyridines via an anomeric-based oxidation mechanism. [ABSTRACT FROM AUTHOR]

In the present study, heterogeneous electro-Fenton (EF) process was applied to remove the sulfasalazine (SU) pharmaceutical from aqueous solutions. In the first part, 3D graphene loaded with Fe@Fe 2 O 3 core-shell nanowires (Fe@Fe 2 O 3 /3D-GO) was used as a cathode electrode in the EF process. Graphene oxide (GO) was synthesized for the synthesis of 3D graphene nanocomposites using the improved Hummers' method and subsequently 3D graphene synthesized by the hydrothermal method using glycine. Finally, Fe@Fe 2 O 3 /3D-GO composite was synthesized and its properties were assessed by Scanning electron microscopy, Atomic force microscopy, Brunauer–Emmett–Teller, Fourier-transform infrared spectroscopy and X-ray diffraction methods. Then, the cathode electrode was prepared using the resulting composite and its performance was evaluated using Cyclic Voltammetry analysis. In the final part of this work, the Fe@Fe 2 O 3 /3D-GO electrode was used as the cathode electrode in the heterogeneous EF process to remove SU from aqueous solutions. The effect of operating parameters such as applied current (mA), initial pH of solution, initial pharmaceutical concentration (mg L−1) and process time (min) on pharmaceutical removal efficiency under heterogeneous EF process was investigated by response surface methodology. The results showed that the optimum values for applied current, pH, initial pharmaceutical concentration and electrolysis time were respectively 300 mA, 7, 30 mg L−1 and 100 min, resulting 99.60% of SU removal. Finally, the intermediates of SU degradation were determined by Gas chromatography–mass spectrometry analysis and the amount of mineralization was determined by total organic carbon analysis. About 5.2% drop in the SU removal efficiency was observed within 8 operational runs. [Display omitted] • 3D graphene loaded with Fe@Fe 2 O 3 core-shell nanowires was applied as cathode. • Electro-Fenton method was applied for Sulfasalazine degradation. • Response surface methodology was used to predict the removal efficiency. • Applied cathode demonstrated 99.60% of Sulfasalazine removal efficiency. • Sulfasalazine removal pH was at neutral range. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new biological uric acid-based nano organocatalyst was synthesized and characterized. • The reusable biological based organocatalyst uric acid tetrakis(methylene phosphonic acid) (UATMPA) was used for the synthesis of novel pyridines with indole moietie as suitable drug candidates. • Mildness, facile workup, high yields, short reaction times, high thermal stability, and reusability of the described catalyst are major advantages of described methodology. In this study, we have designed, synthesized and full characterized a novel biological based acidic nano organocatalyst via condensations reaction of uric acid and phosphorous acid. The obtained compound was named theacrine tetrakis(phosphonic acid) (TTPA) and prepared under refluxing ethanol. This new nano organocatalyst was applied as an efficient and recyclable catalyst for the preparation of novel pyridines with indole moieties via a cooperative vinylogous anomeric based oxidation with good to excellent yields. [ABSTRACT FROM AUTHOR]

Dust deposited on residential and agricultural lands can have serious consequences for the ecosystem when toxic trace elements are present. This study aimed to assess the ecological risk of the trace elements found in the deposited dust around the Mehdi Abad Pb/Zn mine, Yazd, Iran, using several modified pollution indices. The dust samples were collected by the grid method and a Marble Dust Collector (MDCO) sampler to evaluate the concentration of thirty trace elements: nickel (Ni), lead (Pb), barium (Ba), beryllium (Be), chromium (Cr), copper (Cu), dysprosium (Dy), lanthanum (La), lithium (Li), niobium (Nb), tin (Sn), neodymium (Nd), praseodymium (Pr), rubidium (Rb), Ferrum (Fe), sulfur (S), selenium (Se), strontium (Sr), tantalum (Ta), terbium (Tb), zirconium (Zr), tellurium (Te), thorium (Th), titanium (Ti), uranium (U), vanadium (V), yttrium (Y), ytterbium (Yb), thulium (Tm), and cobalt (Co). This study employed multivariate statistical techniques, including Hierarchical cluster analysis (HCA) and the IDW interpolation technique, as well as modified pollution indices such as Enrichment Factor (EF), Modified Pollution Index (MPI), Modified Potential Ecological Risk Index (MRI), and Modified Hazard Quotient (mHQ). All the statistical data analyses were performed via SPSS Statistics, version 22.00. The HCA results showed that all of these trace elements, except Fe, form a group and had similar behavior. The average levels of all elements in the dust samples except for Cr, S, Sr, Ta, Tb, and Te exceeded the background value. The results confirmed that both anthropogenic activities and natural factors were responsible for the trace elements found in the dust. The average EF value for Pb (43.26) indicated its extremely high enrichment in the study area. The MPI, mHQ, and MRI results showed that 33%, 100%, and 33.33% of the dust samples were in the heavily polluted, extreme severity, and high risk categories, respectively. The IDW analysis results revealed that the highest value of the MRI and mHQ indices was in agricultural lands and residential areas; the predominant wind direction also played a role in transferring the elements from the mine to these areas. In general, the results indicated that mining activities increased the ecological risk in Mehdi Abad due to the presence of trace elements, especially Pb. [ABSTRACT FROM AUTHOR]

In this research, magnetite nanoparticles-activated carbon (MNP-AC) electrode was used as cathode through the electro-Fenton (EF) process to degrade Phenazopyridine (PhP). Graphite was used as anode and the reaction time was 120 min. The effects of main variables, including the applied current, initial pharmaceutical concentration, pH and magnetite nanoparticles (MNP) used as catalyst were investigated. PhP degradation efficiency observed for this method was 98.21% under optimum conditions (applied current = 0.2 A, [PhP] 0 = 30 mg/L, pH = 3 and surface ratio of MNP/AC electrode 1:1). Scanning electron microscopy (SEM), Energy Dispersive X-Ray (EDX), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were performed for analyzing the structure of the electrodes. Oxygen reduction activity of the electrodes was examined by cyclic voltammetry (CV). Total organic carbon (TOC) was performed to investigate the PhP removal efficiency during the reaction time and Gas chromatography–mass spectrometry (GC–MS) were performed to analyze degradation by-products of PhP. In the presence of ethanol, the degradation efficiency of PhP was decreased to 54.34%. The PhP degradation efficiency was decreased about 6.93% after eight repeated runs. Based on the results, it was found this method can remove PhP from polluted water. To predict the performance of the degradation efficiency, artificial neural networks (ANN) model was established based on the experimental data. ga1 • Magnetite nanoparticles-activated carbon electrode was applied as cathode. • Artificial neural networks modeling was applied to predict the removal efficiency. • 98.21% of Phenazopyridine removal was observed. • 87.17% of Phenazopyridine mineralization was observed. • Degradation by-products of Phenazopyridine was identified. [ABSTRACT FROM AUTHOR]

In this work, SBA-15/PrN(CH 2 PO 3 H) 2 as a novel and heterogeneous catalyst containing of phosphorous acid groups was fully characterized by using various analysis techniques. A good range of novel pyrido[2,3- d ]pyrimidines and pyrimido[4,5- b ]quinolines were synthesized in the presence of SBA-15/PrN(CH 2 PO 3 H) 2 under solvent-free condition. The major advantages of the described method are high yields, short reaction times and reusability of the catalyst. The obtained results from this research will be supported by the idea of rational designs, syntheses and applications of task-specific catalysts and molecules for the development of biomimetic anomeric based oxidation and/or aromatization mechanism. Image 1 • Study of SBA-15/PrN(CH 2 PO 3 H 2) 2 as a novel and efficient mesoporous solid acid catalyst. • Catalytic application of SBA-15/PrN(CH 2 PO 3 H 2) 2 on the synthesis of new pyrimido[4,5- b ]quinolones. • Catalytic application of SBA-15/PrN(CH 2 PO 3 H 2) 2 on the synthesis of new pyrido[2,3- d ]pyrimidines via anomeric based oxidation. • Easy recovery and reusability of mesoporous solid acid catalyst. [ABSTRACT FROM AUTHOR]

In this study, the superporous hydrogels based on gelatin-methacrylic acid (gelatin-MAA) were synthesized to remove phenazopyridine (PhP) from pharmaceutical waste. Firstly, 27 syntheses based on eight parameters, including crosslinker value, initiator value, initiator ratio, monomer value, gelatin content, mechanical stirring rate, neutralization percentage, and sodium bicarbonate at three levels was optimized by Taguchi method to achieve the high absorbability of porous superabsorbent. The optimized sample has a swelling water amount of 88.8 gw/gads. This sample was used for the removal of PhP from pharmaceutical wastewater. The results showed that 48% of PhP was removed by this method. The optimized hydrogel characterization was performed by Fourier-transform infrared spectroscopy, scanning electron microscopy, and dynamic light scattering. The effective parameters on the removal efficiency of PhP from pharmaceutical waste, including stirring speed, temperature, pH, the concentration of the absorbent, and the absorbent increase times, were investigated with L18 array of Taguchi experimental design. The optimal removal conditions were obtained at PhP concentration of 10 mg/L, pH = 2, the rotation speed of 100 rpm, 60 °C with 0.3 g of synthesized absorbent. Moreover, the kinetics, absorption mechanism of PhP, and thermodynamic parameters were studied. [ABSTRACT FROM AUTHOR]

The current study aimed to investigate responses of fennel (Foeniculum vulgare Mill) plants to salt stress through foliar spray of salicylic acid (SA) as priming agent. SA (0, 0.5 mM) was sprayed on three Iranian populations (Bonab, Hamedan, Moghan) and two foreign populations (German, Gaziantep) three days before imposing salinity (0, 100, 200 mM) and some agronomical and physiological traits were assayed in leaves to determine SA effect as chemical priming agent. Salinity decreased agronomic traits, chlorophyll (Chl) a, b, total Chl, carotenoids and K+, K+/Na+ ratio and increased Na+, malonyldialdehyde (MDA), hydrogen peroxide (H2O2) and total soluble sugar (TSC) in all populations. Fennel populations showed positive responses to SA application regarding the mentioned characters under non-stress and stress conditions through reversing the salinity impacts on the measured parameters. Regarding the obtained results, German and Moghan populations could be considered as the resistant and sensitive populations. In conclusion, SA application as chemical priming could alleviate salt stress effects on fennel populations representing its effectiveness in this regard. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis and characterization of multilinker phosphorous acid anchored En/MIL-100(Cr) as a novel nanoporous catalyst. • Catalytic application of MIL-100(Cr)/NHEtN(CH 2 PO 3 H 2) 2 on the synthesis of tetrahydropyrimido[4,5- b ]quinoline-2,4,6(1 H ,3 H ,7 H)-triones. • Catalytic application of MIL-100(Cr)/NHEtN(CH 2 PO 3 H 2) 2 on the synthesis of tetrahydropyrimido[4,5- b ]quinoline-4,6(3 H ,7 H)-diones. • Catalytic application of MIL-100(Cr)/NHEtN(CH 2 PO 3 H 2) 2 on the synthesis of octahydropyrimido[4,5- b ]quinolin-6(1 H)-one derivatives. A novel ethylenediamine (En) based metal-organic frameworks (MOFs) of Cr-MOFs, En/MIL-100(Cr), containing phosphorous acid tags was prepared. MIL-100(Cr)/NHEtN(CH 2 PO 3 H 2) 2 characterized by a variety of techniques, including fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), elemental mapping and energy dispersive X-ray (EDS), transmission electron microscopy (TEM), Thermal gravimetric (TG), differential thermal gravimetric (DTG), N 2 adsorption-desorption isotherms (BET) and elemental analysis. MIL-100(Cr)/NHEtN(CH 2 PO 3 H 2) 2 successfully applied for the synthesis of new categories of N -heterocyclic compounds such as tetrahydropyrimido[4,5- b ]quinoline-2,4,6(1 H ,3 H ,7 H)-trione, tetrahydropyrimido[4,5- b ]quinoline-4,6(3 H ,7 H)-dione and octahydropyrimido[4,5- b ]quinolin-6(1 H)-one derivatives. More specifically, this paper has explored new tetrahydropyrimido[4,5- b ]quinolone based on uracil (X = S, O). The major advantages of this work are high yields, short reaction times, high stability thermal, facile workup and reusability of the MOFs catalyst. [ABSTRACT FROM AUTHOR]

In the present study, the potential of Azolla filiculoides (A. filiculoides) was first investigated for degradation of Phenazopyridine (PhP), an analgesic drug. The effects of main variables such as initial pharmaceutical concentration, amount of plant, and pH were studied on the efficiency of the biological process. It was observed that A. filiculoides was able to remove pharmaceuticals from contaminated water up to 85.90% during 48 h. Then, the electro-Fenton (EF) method was applied for further removal of PhP yielding a removal rate of about 98.72% under optimum conditions during 2 h. The effects of variables including the current, amount of catalyst, and pH were also studied in this phase. Also, the probability of adsorption was investigated during this step. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed for the used magnetite nanoparticles, total organic carbon (TOC) were performed to investigate PhP removal efficiency during the reaction time and Gas chromatography–mass spectrometry (GC-MS) were performed to analyze degradation byproducts of PhP. Based on the results, it was found that a combination of these bioremediation and electrochemical removal steps were capable of PhP removal from contaminated water. Therefore, this approach may be effective for phytoremediation of pharmaceutical-contaminated aquatic ecosystems. Image 1 • Biological and Electro-Fenton methods were merged for PhP removal. • Azolla filiculoides was used as phytoremediator and Electro-Fenton method used for further removal of PhP. • Effect of operational parameters during the process were examined. • High decolorization and degradation efficiency of PhP was observed using graphite electrodes. • Degradation byproducts of PhP were identified using GC-MS method. [ABSTRACT FROM AUTHOR]

Nanocarbon materials are considered to be active for electrochemical oxygen reduction reaction (ORR) for hydrogen peroxide (H2O2) synthesis. In the present work, a new type of fullerene 60 (C60)-carbon nanotubes (CNTs) hybrid with covalently attached C60 onto outer surface of CNTs was synthesized. The structure of C60-CNT hybrid was confirmed by physical and chemical characterizations and its conformation is proposed featuring the covalent incorporation of CNTs and C60 derivative. C60-CNT hybrid showed high efficiencies on electro-generating H2O2, owing to huge surface area and intermolecular electron-transfer in the hybrid structure. A high H2O2 production rate of 4834.57 mg L−1 h−1 (426.58 mmol L−1) was achieved at − 0.2 V vs saturated calomel electrode (SCE). [ABSTRACT FROM AUTHOR]