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Oenothera biennis water extract was used to perform green nano-biosynthesis of silver nanoparticles (AgNPs) for the removal of amoxicillin (AMX) from water. Scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and energy-dispersive analysis of X-rays were used to approve the synthesis of AgNPs. The average size of AgNPs was determined as 8.10 nm. Antibacterial activities of Staphylococcus aureus and Escherichia coli were also assessed, and the maximum inhibition zones for them were obtained as 19 and 16 mm, respectively. Experimental factors, including contact time, pH, AgNPs dosage, and initial concentration of AMX were investigated. AMX removal efficiency of 97.27% was achieved under the contact time of 30 min, pH 4, adsorbent dosage of 0.5 g, and drug concentration of 30 mg L−1. Evaluation of the isotherm models showed that the adsorption process followed the Langmuir model (R2 = 0.9944) with qmax = 101.01 mg g−1. Moreover, the kinetic studies indicated that the adsorption procedure fitted the pseudo-second-order model with R2 = 0.9997.

In this study, the silver nanoparticles (AgNPs) as an eco-friendly, efficient and low-cost adsorbent was synthesized from Chenopodium botrys extract. Characteristics of the prepared adsorbent were investigated using scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDAX). According to the particle size distribution, the average size of AgNPs was obtained 11.9 nm. AgNPs were used for methyl blue (MB) and methyl orange (MO) removal from aqueous solution. Maximum removal percentages of 97.50 and 95.00 was obtained under optimum conditions, including contact time of 25 min, pH = 10, adsorbent dosage of 0.9 g, and dye concentration of 30 mg/L for MB and MO, respectively. Langmuir isotherm indicated the best results of adsorption related to the MB and MO with the maximum adsorption capacity of (qmax) 90.09 and 80 mg g−1 for MB and MO, respectively. The kinetics study showed that the results were fitted to the pseudo-second-order model with the coefficient of determination (R2) of 0.9984 and 0.9919 for MB and MO, respectively. The process of removal can be also by adsorption of dye molecule on the surface of Ag-NPs and also may be due to the removal of dye molecules by hydroxyl radicals generated by the NPs effect on water molecules in the presence of light. The proposed adsorbent with its great properties can be used to remove contaminants from industrial wastewater before discharge to the environment.

Spectrometric techniques for the analysis of trace Cadmium have developed rapidly due to the increasing need for accurate measurements at extremely low levels of this element in diverse matrices. This review covers separation and preconcentration procedures, and consider the features of the their application with several spectrometric techniques. The use of an appropriate sample handling technique is a must in an analysis of trace Cadmium in water. The efforts to use a solid phase for the recovery of analytes from a water matrix prior to their detection have a long history. The initial experimental applications of SPE resulted in widespread use of this technique in current water analysis and also to adoption of SPE into standardized analytical methods. Cadmium is recognized worldwide as a poisonous metal. Thus, the determination of this element is often required in environmental, biological, food and geological samples. However, these analyses are difficult because such samples contain relatively low concentrations of Cadmium, which fall below the detection limit of conventional analytical techniques such as flame atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. Several preconcentration procedures to determine Cadmium have therefore been devised, involving separation techniques such as liquid–liquid extraction, solid phase extraction, coprecipitation and cloud point extraction. Review of preconcentration procedures for determining Cadmium using spectroanalytical techniques. A brief overview of the history of the use of SPE in trace Cadmium analysis of water is given in presented paper.

Two proteins, i.e. bovine serum albumin and egg white lysozyme are used as model adsorbents for the food industry (dairy) wastewater and multi-walled carbon nanotubes (MWCNT) and amine functionalized multi-walled carbon nanotubes (MWCNT-NH2) surfaces were used as adsorbents. Various effective parameters such as contact time, the initial concentration of proteins, initial pH levels, and temperature were well investigated and optimized using batch adsorption study. Upon optimization, it was observed that the on increasing the initial concentration the adsorption of both the proteins also increases. The equilibrium adsorption data of Lysozyme using MWCNTs and MWCNT-NH2as adsorbents were well fitted and in good agreement with the type (II) Langmuir isotherm model and Freundlich isotherm model, respectively, while on the other hand, for serum albumin adsorption using MWCNTs and MWCNT-NH2 as adsorbents were described was well fitted and in good agreement with type (II) Langmuir isotherm model.

Developing low cost and environmentally friendly methods for metallic nanoparticles is an increasing need. Using plants towards synthesis of nanoparticles are beneficial with the presence of bio-molecules in plants, which can act as capping/stabilizing and reducing agents. In the present attempt, we describe rapid biosynthesis of silver nanoparticles by Satureja intermedia C. A. Mey (Lamiaceae) aqueous extract. Synthesized nanoparticles were characterized by UV–Visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and the chemical groups in plant extract were detected by Fourier Transform Infra-Red (FT-IR) spectroscopy. The XRD study showed crystalline nature and face cubic center shape for nanoparticles. TEM study showed that the mean diameter and standard deviation for the silver nanoparticles were 29.29 ± 28.18 nm. Total phenolic and flavonoid contents and radical scavenging activity of the aqueous extract and SNPs/extract mixture, were also evaluated in this study. It can be concluded that the aerial parts of S. intermedia is a good source of phenolic compounds, a potent antioxidant and a valuable choice for bio-reduction and biosynthesis of silver nanoparticles.

The composition of the volatile oils from the seeds, shoots and roots of Echinophora orientalis Hedge & Lamond, a perennial aromatic herb of the family Apiaceae growing in Iran, was analyzed by GC-MS and GC-FID. Essential oil of this plant has been used as a natural preservative in dairy products industries. There were at least six compounds, α-pinene, myrcene, p-cymene, l-limonene, p-cymen-8-ol and 1,7- octadiene 3,6-dimethylene, common in seeds, shoots and roots volatile oils. While, m-tolualdehyde, cuminal, perillene and germacrene D were present both in seeds and shoots volatile oils, spathulenol was found in both seeds and roots volatile oils. Myristicin, terpenolene, α-phellandrene and 1,5,5-trimethyl-6-(3-methyl-buta-1,3- dienyl)-cyclohexene were identified in the volatile oils of shoots and roots of E. orientalis. The volatile oils of the seeds, unlike roots and shoots, had high percentage of sesquiterpenes. The roots and shoots volatile oils were found to be rich in monoterpenes. Oxygenat...

Adsorption capacity of Pb2 + on graphene oxide and thiol functionalized graphene oxide was well investigated and illustrated in the present work. Variable cysteamine concentrations i.e., 60, 80 and 100 mg were used as functionalizing agent for conversion of graphene oxide to thiol functionalized graphene oxide. The surface of graphene oxide (GO) was functionalized by the use of 60 mg of cysteamine (GO-SH1), by 80 mg of cysteamine (GO-SH2) and by 100 mg of cysteamine (GO-SH3), respectively. The prepared adsorbents were characterized using Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The impact of several influential parameters such as adsorption time, pH, temperature and cysteamine concentrations on Pb2 + adsorption was well elucidated and optimized. The optimized values of adsorbent dose, initial concentration of Pb2 +, contact time, and pH were found to be 20 mg, 25 mg/L, 60 min and 6 respectively at a temperature of 298 K. The kinetic experimental data for GO surface was well fitted and found to be in good agreement with type (II) of pseudo-second-order model, and for GO-SH1, GO-SH2, and GO-SH3 the experimental data was in good agreement with pseudo first-order model, type (IV) of pseudo-second-order model and type (II) of pseudo-second-order model respectively. Results revealed that the adsorption capacity of Pb2 + on to the developed adsorbent increases with the increase in temperature, hence this process was endothermic in nature.

Efficient adsorbent graphene oxide (GO) and its derivative, i.e., thiol-functionalized graphene oxide (GO-SH), was used for the removal of noxious Pb(II) ion from the aqueous phase. Different amounts, i.e., 60, 80, and 100 mg of cysteamine, were used as functionalizing agent to functionalize the GO with thiol group; hence, three different nanocomposites, i.e., GO-SH1, GO-SH2, and GO-SH3 were prepared from the different amount of the cysteamine. The developed nanocomposites were characterized using various analytical techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analysis. The whole removal and adsorption process was well illustrated and investigated. The impact of influential factors including initial concentration, pH, contact time, temperature, and concentrations cysteamine on the adsorption properties of Pb(II) from aqueous solution was well elucidated and optimized. The obtained equilibrium results were inserted in various adsorp...

Adsorption of p-nitrophenol and naphthalene in single aqueous solution from petrochemical wastewater by single-walled carbon nanotubes (SWCNTs) and functionalized single-walled carbon nanotubes having covalent attachments of carboxylic groups (SWCNT-COOH) has been considered. Removal behavior of p-nitrophenol and naphthalene by SWCNTs and SWCNT-COOH surfaces was studied by varying the parameters such as agitation time, initial concentration, and pH of solution. The presence of surface functional groups affected the adsorption capacity of SWCNTs and SWCNT-COOH surfaces for removal of p-nitrophenol and naphthalene in single aqueous solution from petrochemical wastewater. Kinetic studies were performed and pseudo-second-order kinetic model successfully represented the kinetic data. The Langmuir and Freundlich adsorption isotherms were used for description of adsorption equilibrium, and it was found that the experimental data fitted well with the Langmuir model. The results of the study show that the carbon n...

The oils obtained by hydrodistillation of the aerial parts of Salvia brachyantha Bords. (probed.) and Stachys byzantina C. Koch grown in Iran, were analyzed by GC and GC-MS .Forty five compounds representing 95.06 % of the oil of S. brachyantha were identified of which 1,8-cineole (10.19 %), γ-muurolene (7.54 %), caryophyllene oxide (6.66 %), spathulenol (6.19 %) and elemol (5.89 %) were the major constituents. Furthermore 1,8-Cineole (16.35 %), hexadecanioc acid (7.42 %), camphor (6.76 %) and borneol (5.74 %) were found as the main components among 25 constituents in the oil of St. byzantina representing 94.30 % of the total compounds. Acetone extract of the aerial parts of two herbs were tested against 6 gram(+/-) bacteria by measurement of growth inhibitory zones.

The equilibrium and thermodynamics of Pb(II), Cd(II) and Cu(II) ions adsorption from aqueous solution onto single-walled carbon nanotube (SWCNT) and carboxylate group functionalized single-walled carbon nanotube (SWCNT-COOH) surfaces were studied by atomic absorption spectroscopy. The effect of contact time, pH, initial concentration of ion, ionic strength and temperature on the adsorption of ion was investigated. The results indicated that Langmuir model fits adsorption isotherm data better than the Freundlich model. The results also demonstrated that SWCNT-COOH surfaces can more effectively adsorb mentioned ions than a SWCNT surface. Maximum adsorption capacities (qm) for Pb(II), Cu(II) and Cd(II) ions onto SWCNT-COOH were obtained as 96.02, 77.00 and 55.89 mg/g, respectively, and by SWCNTs as 33.55, 24.29 and 24.07 mg/g, respectively. Thermodynamic parameters values showed that the adsorption of ions on SWCNT-COOH and SWCNTs at 283–313 K is spontaneous and endothermic.

Water-distilled essential oils from the aerial parts of Micromeria persica Boiss., leaves and stems of Hymenocrater platystegius Rech. f., which are endemic to Iran, and the aerial parts of Scutellaria pinnatifida A. Hamilt. subsp. pinnatifida were analyzed by GC and GC/MS. Twenty-four components representing 96.1% of the oil of M. persica were identified of which linalool (15.2%), α-pinene (15.0%) and (E)-nerolidol (13.8%) were found to be the major constituents. Seventeen compounds representing 91.7% of the leaf oil and 10 compounds representing 90.7% of the stem oil of H. platystegius were identified. Both oils were rich in α-pinene (16.7% and 18.6%, respectively) and spathulenol (17.1% and 17.9%, respectively). The other main component of the leaf oil was 1,8-cineole (12.9%), and of the stem oil, cis-calamenene (11.2%). Methyl chavicol (81.9%) was the main component among the 11 constituents characterized in the oil of S. pinnatifida representing 100% of the total components detected.

The objective of this study is to improve the catalytic activity of platinum by alloying with transition metal (Pd) in gas diffusion electrodes (GDEs) by oxygen reduction reaction (ORR) at cathode site and comparison of the acidic and alkaline electrolytes. The high porosity of single-walled carbon nanotubes (SWCNTs) facilitates diffusion of the reactant and facilitates interaction with the Pt surface. It is also evident that SWCNTs enhance the stability of the electrocatalyst. Functionalized SWCNTs are used as a means to facilitate the uniform deposition of Pt on the SWCNT surface. The structure of SWCNTs is nearly perfect, even after functionalization, while other types of CNTs contain a significant concentration of structural defects in their walls. So catalysts supported on SWCNTs are studied in this research. The electrocatalytic properties of ORR were evaluated by cyclic voltammetry, polarization experiments, and chronoamperometry. The morphology and elemental composition of Pt alloys were characterized by X-ray diffraction (XRD) analysis and inductively coupled plasma atomic emission spectroscopy (ICP-AES) system. The catalytic activities of the bimetallic catalysts in GDEs have been shown to be not only dependent on the composition, but also on the nature of the electrolytes. The GDEs have shown a transition from the slow ORR kinetics in alkaline electrolyte to the fast ORR kinetics in the acidic electrolyte. The results also show that introduction of Pd as transition metal in the Pt alloys provides fast ORR kinetics in both acidic and alkaline electrolytes. The performance of GDEs with Pt–Pd alloy surfaces towards the ORR as a function of the alloy’s overall composition and their behavior in acidic electrolyte was also studied. These results show that the alloy’s overall composition and also the nature of the electrolytes have a large effect on the performance of GDEs for ORR.

Electrooxidation of methanol on glassy carbon (GC) electrode modified by optimum carbon supported Pt electrocatalyst (Pt-C/GC) in acid media is investigated. The catalyst is prepared by ultrasonicating Pt/C powders in aqueous media. The activity of prepared Pt-C/GC electrode is studied in potential range of 0–1000 mV (versus SCE) by cyclic voltammetry. The results showed that the Pt/C dispersed layer at the surface of glassy carbon electrode, behaves as an electrocatalyst for the oxidation of methanol in acid medium by optimum loading of Pt (0.2 mg cm−2). The electrochemical properties of prepared electrode are studied under various conditions. However the effect of various parameters in the catalytic enhancement of Pt/C, such as platinum loading, sulfuric acid concentration, different scan rates, different final potentials, and medium temperature are considered and examined.

The composition of the essential oils from three Salvia species of Iran: Salvia sclareopsis Bornm. ex Hedge., Salvia brachysiphon Stapf, which are endemic to Iran, and Salvia verbascifolia M.Bieb., obtained by hydrodistillation were analyzed by GC and GC/MS. The oils of S. sclareopsis and S. verbascifolia were rich in β-caryophyllene (22.5% and 18.5%) and germacrene D (16.5% and 34.1%), respectively. The other main component of the first oil was benzyl benzoate (13.7%) and in the latter one was caryophyllene oxide (10.3%). In the oil of S. brachysiphon, also β-caryophyllene (28.1%), α-pinene (20.6%), limonene (11.5%) and β-pinene (10.6%) were found to be the major constituents.

The composition of the essential oils of Nepeta denudate Benth. and N. cephalotes Boiss., which are endemic to Iran, was investigated by means of GC, GC/MS and 1H-NMR spectra of the main compounds, 1,8-cineole (48.0%), myrtenol (5.0%), β-pinene (4.6%) and trans-pinocarveol (4.5%) were the main components among the 21 constituents characterized in the oil of N. denudata, representing 85.7% of the total components detected. Ten compounds were identified in the oil of N. cephalotes representing 78.5% of the total oil with 4aα, 7α, 7aα-nepetalactone (35.1%), β-pinene (18.2%) and 1,8-cineole (11.4%) as the major constituents. The structure of 1,8-cineole, nepetalactone and β-pinene were confirmed by their 1H-NMR spectra.

The composition of the essential oils of Artemisia santolina Schrenk and Artemisia gypsacea Krasch., M. Pop. et Lincz. ex Poljak. have been analyzed by GC and GC/MS. The volatile oil of A. santolina was found to contain: lavandulol (37.2%), 1,8-cineole (15.9%), linalool (13.6%) and lavandulyl acetate (9.5%) as major constituents. The oil of A. gypsacea was characterized by higher amounts of 1,8-cineole (36.5%), β-thujone (28.4%) and α-thujone (8.9%).

Water-distilled essential oil from aerial parts of Ruta chalepensis L. was analyzed by GC and GC/MS. Eleven compounds representing 92.9% of the oil were identified. 2-Undeeanone (52.5%) and 2-nonanone (24.1%) were the major constituents.

The essential oil obtained by hydrodistillation of the aerial parts of Artemisia aucheri Boiss. was analyzed by GC and GC/MS. Seventeen components were identified, constituting 88.2% of the oil. The major components were camphor (45.5%) and 1,8-cineole (14.3%).

Water-distilled essential oil from aerial parts of Froriepa subpinnata (Ledeb.) Baill. was investigated by means of GC, GC/MS and 1H-NMR spectra of the main compounds. Ten components were identified, constituting 90% of the oil, the major constituents being β-phellandrene (50.3%) and sabinene (25.7%).

The chemical composition of the essential oil obtained from the aerial parts of Ferula stenocarpa Boiss., a native plant of Iran, was examined by using GC and GC/MS. Twenty-six compounds constituting 97.8% of the total components detected were identified. α-Pinene (48.8%) and β-pinene (30.1%) were found to be the major components in the oil

The essential oil isolated by hydrodistillation from the aerial parts of Salvia lereifolia Benth. was analyzed using GC (retention indices) and GC/MS. Twenty-two components representing 93.4% of the oil were characterized. The major constituents found were β-pinene (23.7%), 1,8-cineole (16.2%), α-pinene (13.8%) and α-cadinol (9.0%).

The essential oil of Haplophyllum tuberculatum (Forssk.) A. Juss. was analyzed by GC and GC/MS. The main constituents were limonene (27.3%) and α-pinene (21.9%).

The essential oil of the aerial parts of Prangos latiloba Korov was analyzed by GC and GC/MS. The main constituents were α-pinene (25.1%), limonene (16.1%) and myrcene (9-5%).

The essential oil of the aerial parts of Tanacetum polycephalum was analyzed by capillary GC and GC/MS. The main constituents were camphor (18.2%), 1,8-cineole (17.0%), carveol (9.1%) and trans-isopulegone (8.0%).

The essential oils of Achillea aucheri Boiss. and A. kellalensis Boiss. et Hausskn., which are endemic to Iran, have been analyzed by GC and GC/MS. The oil of A. aucheri was found to contain 1,8-cineole (40.7%), α-terpineol (11.3%), β-pinene (10.8%) and α-pinene (10.3%) as major constituents. The oil of A. kellalensis was characterized by a higher amount of camphor (34.0%), borneol (12.6%), α-thujone (12.5%), 1,8-cineole (11.3%), bornyl acetate (7.3%) and camphene (7.0%).