Removal of copper, nickel and zinc by sodium dodecyl sulphate coated magnetite nanoparticles from water and wastewater samples

AbstractIn the present study, sodium dodecyl sulphate-coated Fe3O4 nanoparticles (SDS–Fe3O4 NPs) were applied to remove Cu(II), Ni(II) and Zn(II) ions from water and wastewater samples. The effects of pH of solution, SDS, Fe3O4 NPs and salt addition on removal efficiency of the metal ions were investigated and optimized. Salt addition has a negative effect on the removal efficiency of the metal ions, thus extraction follows the ion exchange mechanism. The results showed that the adsorption process onto the adsorbent is very fast under optimum conditions and nearly 1min of contact time was found to be sufficient for completion of the metal ions' adsorption. Adsorption equilibrium of the metal ions reveals that data were fitted well to the Langmuir isotherm. Also, the maximum monolayer capacity, qmax, obtained from the Langmuir isotherm was 24.3, 41.2 and 59.2mgg−1 for Cu(II), Ni(II) and Zn(II), respectively. Desorption experiments by elution of the adsorbent with methanol show that the SDS-Fe3O4 NPs could be reconditioned without significant loss of its initial properties even after three adsorption–desorption cycles. Finally, application of the SDS-Fe3O4 NPs as efficient adsorbent material for removal of the metal ions from Iran Khodro's wastewater samples was investigated and satisfactory results were obtained

Comparison Between the Efficiency of Plain GAC and Supported GAC With Manganese Oxide for Toluene Adsorption From Waste Air Stream

Objectives Type of adsorbent is the most important parameter to adsorb volatile organic compounds (VOCs) from the air stream. Application of a selective adsorbent could lead to the higher efficiency and lower costs in the adsorption processes. The current study aimed at investigating the efficiency of manganese oxide impregnated on GAC support (MnO/GAC) to remove toluene from air stream. The efficiency of MnO/GAC and GAC absorbents for toluene removal were compared at the same experimental conditions.Methods The MnO/GAC preparation method was Sol-gel. Retention time (0.5, 1, 1.5, 2, and 4 seconds), inlet toluene concentration (100, 200, 300, and 400 part per million, by volume) and the temperature of the air stream (25, 50, 75, and 100�C) were examined as the main functional parameters in the adsorption process.Results Breakthrough time of MnO/GAC adsorbent in comparison to that of the plain GAC increased 6 to 11 at the retention time of 0.5 to 4 seconds. Adsorption capacity of GAC and MnO/GAC increased 67.9 and 61.1 by increasing inlet toluene concentration from 100 to 400 ppmv, respectively. Breakthrough time of GAC and MnO/GAC decreased 57.9 and 59.6 by increasing inlet toluene concentration from 100 to 400 ppmv, respectively. Breakthrough time of GAC decreased from 41 to 26 hours by increasing the temperature of the air stream from 25�C to 100�C. Direct air temperature increase affected the MnO/GAC efficiency for toluene adsorption and the breakthrough time increased from 46 to 57 hours.Conclusion Results of the current study showed that MnO/GAC could be applied as a good substitution for GAC in the adsorption of VOCs from air streams

Modified magnetite nanoparticles with cetyltrimethylammonium bromide as superior adsorbent for rapid removal of the disperse dyes from wastewater of textile companies

This paper reports application of cetyltrimethylammonium bromide (CTAB) coated magnetite nanoparticles (Fe3O4 NPs) as a novel adsorbent for removal of two types of disperse dyes, including disperse red 167, and disperse blue 183, from wastewater of textile companies. The effect of parameters including type of surfactant, pH of solution, surfactant concentration, and amount of salt, was investigated and optimized. The obtained results showed that the ratio of initial dye concentration to CTAB amounts has critical effect on removal processes so that removal efficiencies higher than 95% can be achieved even at high concentration of dyes as high as 500 mg l-1 when the ratio is optimum. Removal of dyes is very fast, and equilibrium is reached at times less than 10 min even for high concentration of the dyes. Very high adsorbent capacity (as high as 2000 mg g-1) was yielded for maximum tested concentration of the dyes (500 mg g-1). The obtained result was confirmed by thermogravimetric analysis data. This study showed that CTAB coated Fe3O4 NPs is a very efficient adsorbent for removal of dyes from wastewater of textile companies and has high capacity under optimum conditions

Preparation of 5-fluorouracil nanoparticles by supercritical antisolvents for pulmonary delivery

This study concerns the supercritical antisolvent process which allows single-step production of 5-fluorouracil (5-FU) nanoparticles. This process enhances the physical characteristics of 5-FU in order to deliver it directly to the respiratory tract. Several mixtures of methanol with dichloromethane, acetone, or ethanol were used for particle preparation, and their effects on the physical characteristics of the final products were studied. The conditions of the experiment included pressures of 100 and 150 bar, temperature of 40°C, and a flow rate of 1 mL/min. The particles were characterized physicochemically before and after the process for their morphology and crystallinity. In spite of differences in size, the particles were not very different regarding their morphology. The resulting particles were of a regular shape, partly spherical, and appeared to have a smooth surface, whereas the mechanically milled particles showed less uniformity, had surface irregularities and a high particle size distribution, and seemed aggregated. Particles of 5-FU precipitated from methanol-dichloromethane 50:50 had a mean particle size of 248 nm. In order to evaluate the aerodynamic behavior of the nanoparticles, six 5-FU dry powder formulations containing mixtures of coarse and fine lactose of different percentages were prepared. Deposition of 5-FU was measured using a twin-stage liquid impinger and analyzed using a validated high pressure liquid chromatography method. Addition of fine lactose improved the aerodynamic performance of the drug, as determined by the fine particle fraction

On-Chip Electromembrane Surrounded Solid Phase Microextraction for Determination of Tricyclic Antidepressants from Biological Fluids Using Poly(3,4-ethylenedioxythiophene)—Graphene Oxide Nanocomposite as a Fiber Coating

In the present study, on-chip electromembrane surrounded solid phase microextraction (EM-SPME) was employed in the determination of tricyclic antidepressants (TCAs), including amitriptyline, nortriptyline, imipramine, desipramine, maprotiline, and sertraline, from various biological fluids. In this regard, poly(3,4-ethylenedioxythiophene)–graphene oxide (PEDOT-GO) was electrodeposited on an SPME fiber as a conductive coating, then the fiber played the acceptor-electrode role during the extraction. Thus, the immigration of the analytes under the influence of an electric field and their absorption onto the fiber coating were accomplished simultaneously. Under the optimized conditions, the limits of detection for the target analytes were acquired in the range of 0.005–0.025 µg L−1 using gas chromatography–mass spectrometry. The linearity of the method was 0.010–500 µg L−1 for the imipramine and sertraline, 0.025–500 µg L−1 for the amitriptyline, nortriptyline, and desipramine, and 1.000–250 µg L−1 for the maprotiline (R2 ≥ 0.9984). Moreover, this method provided suitable precision and fiber-to-fiber reproducibility, with RSDs ≤ 8.4%. The applicability of the proposed setup was eventually investigated for extraction of the drugs from human bone marrow aspirate, urine, plasma, and well water samples, in which satisfactory relative recoveries, from 93–105%, were obtained

Extraction and determination of trace amounts of chlorpromazine in biological fluids using magnetic solid phase extraction followed by HPLC

A simple, rapid and sensitive method termed as magnetic solid phase extraction (MSPE) combined with high-performance liquid chromatography-ultraviolet detector (HPLC-UV) has been proposed for the determination of trace amounts of chlorpromazine (CPZ) in water, urine and plasma samples. The separation and determination was performed on a C18 column under the optimal chromatographic conditions. Several factors influencing the extraction efficiency of CPZ, such as pH, surfactant and adsorbent amounts, ionic strength, extraction time, sample volume and desorption conditions, were studied and optimized. Under the optimal MSPE conditions, the extraction percentage of CPZ was 74%, 27% and 16% in water, urine and plasma samples, respectively. The limits of detection (LODs) of the proposed approach were 0.1, 5.0 and 10 ng/mL in water, urine and plasma samples, respectively. The relative standard deviations (RSDs) based on five replicate determinations at 10 ng/mL level of CPZ was 1.2%. Good linear behaviors over the investigated concentration ranges (0.25â300 ng/mL) with good coefficient of determination, R2>0.9998, were obtained. Good spike recoveries with relative errors less than 9.0% were obtained when applying the proposed method to water, urine and plasma samples. Keywords: Chlorpromazine, Magnetic solid phase extraction, Mixed-hemimicelle

Comparison Between the Efficiency of Plain GAC and Supported GAC With Manganese Oxide for Toluene Adsorption From Waste Air Stream

Objectives Type of adsorbent is the most important parameter to adsorb volatile organic compounds (VOCs) from the air stream. Application of a selective adsorbent could lead to the higher efficiency and lower costs in the adsorption processes. The current study aimed at investigating the efficiency of manganese oxide impregnated on GAC support (MnO/GAC) to remove toluene from air stream. The efficiency of MnO/GAC and GAC absorbents for toluene removal were compared at the same experimental conditions.Methods The MnO/GAC preparation method was Sol-gel. Retention time (0.5, 1, 1.5, 2, and 4 seconds), inlet toluene concentration (100, 200, 300, and 400 part per million, by volume) and the temperature of the air stream (25, 50, 75, and 100�C) were examined as the main functional parameters in the adsorption process.Results Breakthrough time of MnO/GAC adsorbent in comparison to that of the plain GAC increased 6 to 11 at the retention time of 0.5 to 4 seconds. Adsorption capacity of GAC and MnO/GAC increased 67.9 and 61.1 by increasing inlet toluene concentration from 100 to 400 ppmv, respectively. Breakthrough time of GAC and MnO/GAC decreased 57.9 and 59.6 by increasing inlet toluene concentration from 100 to 400 ppmv, respectively. Breakthrough time of GAC decreased from 41 to 26 hours by increasing the temperature of the air stream from 25�C to 100�C. Direct air temperature increase affected the MnO/GAC efficiency for toluene adsorption and the breakthrough time increased from 46 to 57 hours.Conclusion Results of the current study showed that MnO/GAC could be applied as a good substitution for GAC in the adsorption of VOCs from air streams

Three-Dimensional Network of Highly Uniform Cobalt Oxide Microspheres/MXene Composite as a High-Performance Electrocatalyst in Hydrogen Evolution Reaction

Due to its affordable cost, excellent redox capability, and relatively effective resistance to corrosion in alkaline environments, spinel Co3O4 demonstrates potential as a viable alternative to noble-metal-based electrocatalysts. Nevertheless, these materials continue to exhibit drawbacks, such as limited active surface area and inadequate intrinsic conductivity. Researchers have been trying to increase the electrical conductivity of Co3O4 nanostructures by integrating them with various conductive substrates due to the low conductivity of pristine Co3O4. In this study, uniform cobalt glycerate solid spheres are first synthesized as the precursor and subsequently transformed into cobalt oxide microspheres by a simple annealing procedure. Co3O4 grown on the surface of Ti3C2Tx-MXene nanosheets (Co3O4/MXene) was successfully synthesized through electrostatic attraction. In order to create a positively charged surface, the Co3O4 microspheres were treated with aminopropyltriethoxysilane. The Co3O4/MXene exhibited a low overpotential of 118 mV at 10 mA cm–2 and a Tafel slope of 113 mV dec–1 for the hydrogen evolution reaction, which is much lower than the pristine Co3O4 at 232 and 195.3 mV dec–1

Simultaneous determination of steroid drugs in the ointment via magnetic solid phase extraction followed by HPLC-UV

The copper-coated iron oxide nanoparticles with core-shell were produced by deposition of a Cu shell on Fe3O4 NPs through reduction of Cu2+ ions in solution using NaBH4. Subsequently, the organosulfur compound, bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid (b-TMP-DTPA), was used to form self-assembled monolayer in order to modify sorbent's surface via covalent bonding between Cu and thiol (–SH) terminal groups. The prepared magnetic nanoparticles were characterized by using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and thermo gravimetric analysis (TGA). Then, the application of this new sorbent was investigated to extract the steroid drugs in ointment samples with the aid of ultrasound. An external magnetic field was applied to collect the magnetic nanoparticles (MNPs). The extracted analytes were desorbed using acetonitrile. The obtained extraction solution was analyzed by HPLC-UV. The main affecting factors on the extraction efficiency including pH, sonication time, amount of sorbent, salt concentration, and desorption conditions were optimized in detail. Under the optimum conditions, good linearity was obtained in the range of 2.5–250.0 µg/ L with reasonable linearity (R2 > 0.99) and the limits of detection (LODs) ranged between 0.5 and 1.0 µg/L (based on S/N = 3). Repeatability (intra-day precision) based on five replicates and preconcentration factors were calculated to be 3.6%–4.7% and 87–116, respectively. Relative recoveries in ointment samples at two spiked levels of the target analytes were obtained in the range of 90.0%–103.2%. The results illustrated that the Fe3O4@Cu@ b-TMP-DTPA NPs have the capability of extraction of steroid drugs from ointment samples. Keywords: Magnetic nanoparticles, Steroid drug, Ointment, High performance liquid chromatography, Self-assembled monolaye

Optimization and Comparison of Ultrasound-Assisted Extraction of Estragole from Tarragon Leaves with Hydro-Distillation Method

A comparative study of ultrasound-assisted extraction (UAE) and hydro-distillation was performed for fast extraction of estragole from tarragon (Artemisia dracunculus L.) dried leaves. Several influential parameters of the UAE procedure in the extraction of estragole (type of solvent, extraction cycles, solvent to material ratio, irradiation time and particle size) were investigated and optimized. It was found that UAE offers a more rapid extraction of estragole than hydrodistillation. The optimum parameters were solvent to material ratio of 8:1 v/m, 96% (w/w) ethanol in water as extraction solvent, particle size of 1.18 mm, irradiation time of 5 min, output power of 63 W, 9 pulses, and ultrasonic frequency of 20 kHz. The recovery of estragole by UAE under optimal conditions was 44.4% based on dry extract. The benefit of ultrasound was to decrease the extraction time (5 min) relative to the classical hydrodistillation method (3 h). The experimental results also indicated that ultrasound-assisted extraction is a simple, rapid and effective method for extraction of the volatile oil components of tarragon