Nanoporous hydrogel absorbent based on salep: Swelling behavior and methyl orange adsorption capacity.

This study used the gas-blowing method to develop a nanoporous hydrogel using poly (3-sulfopropyl acrylate-co-acrylic acid-co-acrylamide) grafted onto salep. The synthesis of the nanoporous hydrogel was optimized by various parameters for maximum swelling capacity. The nanoporous hydrogel was characterized using FT-IR, TGA, XRD, TEM, and SEM analyses. Images from SEM showed numerous pores and channels in the hydrogel with an average size of about 80 nm, forming a honeycomb-like shape. The change in surface charge was investigated by zeta potential and revealed that the surface charge of the hydrogel ranged from 20 mV at acidic conditions to -25 mV at basic conditions. The swelling behavior of optimum superabsorbent hydrogel was determined under different environmental conditions, such as different pH values, ionic strengths of the environment, and solvents. In addition, the swelling kinetics and the absorbance under loading of the hydrogel sample in different environments were investigated. Moreover, Methyl Orange (MO) dye was removed from aqueous solutions using the nanoporous hydrogel as an adsorbent. The adsorption behavior of the hydrogel was examined under various conditions, and the adsorption capacity of the hydrogel was found tobe 400 mg g-1. The maximum water uptake was obtained under the following conditions: Salep weight = 0.01 g, AA = 60 µL, MBA = 300 µL, APS = 60 µL, TEMED = 90 µL, AAm = 600 µL, and SPAK = 90 µL. Lastly, the adsorption kinetics was studied by employing pseudo-first-order, pseudo-second-order, and intra-particle diffusion models.

Photocatalytic degradation of remdesivir nucleotide pro-drug using [Cu(1-methylimidazole)4(SCN)2] nanocomplex synthesized by sonochemical process: Theoretical, hirshfeld surface analysis, degradation kinetic, and thermodynamic studies.

The first ultrasonic synthesis of [Cu(L)4(SCN)2] (L = 1-methylimidazole) nanocomplex was carried out under ultrasonic irradiation, and its photocatalytic performance for the degradation of remdesivir (RS) under sunlight irradiation was comprehensively investigated for the first time in this study. The physicochemical properties of the synthesized photocatalyst were examined by Fourier-transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), diffuse reflectance spectroscopy (DRS), and thermogravimetric analysis (TGA) techniques. The band gap of the synthesized [Cu(L)4(SCN)2] nanocomplex was determined to be 2.60 eV by the diffuse reflectance spectroscopy method using Kubelka-Munk formula. The photocatalytic performance of nanocomplex was examined for the removal of remdesivir under sunlight from water for which the results indicated that an amount of 0.5 gL-1 of the [Cu(L)4(SCN)2] nanocomplex was sufficient to remove more than 96% remdesivir from its 2 mg L-1 concentration within 20 min, at pH = 6. The kinetic data showed that the photodegradation onto the [Cu(L)4(SCN)2] nanocomplex has a high correlation (0.98) with the pseudo-second-order kinetic model. The decrease in chemical oxygen demand (COD) (from 70.5 mg L-1 to 36.4 mg L-1) under optimal conditions clearly confirmed the mineralization of the RS drug. The values of ΔS° (-0.131 kJ mol-1 K-1) and ΔH° (-49.750 kJ mol-1) were negative, indicating that the adsorption process was spontaneous and more favorable in lower temperatures. Moreover, the RS structure in the open shell state and the high HOMO and LUMO gaps based on the M06/6-31 + G (d) level of theory may be a confirmation of this fact. In addition, the Hirshfeld surface analysis (HSA) of the crystal packing of the prepared complex was discussed in detail to evaluate the interactions between the crystal packings. The results of this study confirm that the [Cu(L)4(SCN)2] nanocomplex can be successfully used for the photodegradation of pharmaceutical contaminants.

A Novel N-Doped Nanoporous Bio-Graphene Synthesized from Pistacia lentiscus Gum and Its Nanocomposite with WO3 Nanoparticles: Visible-Light-Driven Photocatalytic Activity.

This paper reports the synthesis of a new nitrogen-doped porous bio-graphene (NPBG) with a specific biomorphic structure, using Pistacia lentiscus as a natural carbon source containing nitrogen that also acts as a bio-template. The obtained NPBG demonstrated the unique feature of doped nitrogen with a 3D nanoporous structure. Next, a WO3/N-doped porous bio-graphene nanocomposite (WO3/NPBG-NC) was synthesized, and the products were characterized using XPS, SEM, TEM, FT-IR, EDX, XRD, and Raman analyses. The presence of nitrogen doped in the structure of the bio-graphene (BG) was confirmed to be pyridinic-N and pyrrolic-N with N1 peaks at 398.3 eV and 400.5 eV, respectively. The photocatalytic degradation of the anionic azo dyes and drugs was investigated, and the results indicated that the obtained NPBG with a high surface area (151.98 m2/g), unique electronic properties, and modified surface improved the adsorption and photocatalytic properties in combination with WO3 nanoparticles (WO3-NPs) as an effective visible-light-driven photocatalyst. The synthesized WO3/NPBG-NC with a surface area of 226.92 m2/g displayed lower bandgap and higher electron transfer compared with blank WO3-NPs, leading to an increase in the photocatalytic performance through the enhancement of the separation of charge and a reduction in the recombination rate. At the optimum conditions of 0.015 g of the nanocomposite, a contact time of 15 min, and 100 mg/L of dyes, the removal percentages were 100%, 99.8%, and 98% for methyl red (MR), Congo red (CR), and methyl orange (MO), respectively. In the case of the drugs, 99% and 87% of tetracycline and acetaminophen, respectively, at a concentration of 10 mg/L, were removed after 20 min.

Rapid ultrasound-assisted microextraction of atorvastatin in the sample of blood plasma by nickel metal organic modified with alumina nanoparticles.

In the present work, nickel-1,4-benzenedioxyacetic acid was synthesized as a rod-like metal organic material and then modified with alumina nanoparticles to synthesize nickel metal organic modified-Al2 O3 nanoparticles. The material was found as an efficient sorbent for the enrichment of atorvastatin in human blood plasma. After the extraction of the sample of plasma by ultrasound-assisted dispersive solid phase extraction, high performance liquid chromatography-ultraviolet was used to determine the quantitatively pre-concentrated interest analyte. The conditions for optimum extraction were achieved by the optimization of the volume of eluent, dosage of the sorbent, and time of sonication. Solution pH of 7.0, 250 µL of ethanol, 45 mg of the sorbent, and 10 min of sonication time were the conditions for extracting the atorvastatin maximum recovery of higher than 97.0%. By using desirability function for the optimization of the process, the present method showed a response that was linear ranging from 0.2 to 800 ng/mL with regression coefficient of 0.999 in the plasma of human blood with a satisfactory detection limit of 0.05 ng/mL, while the precision of interday for the current method was found to be <5%. It can be concluded that dispersive solid phase extraction method is effective for the extraction of atorvastatin from human plasma samples (97.4-102%) due to its easy operation, simplicity, repeatability, and reliability.

Pre-concentration of trace amount of bisphenol A in water samples by palm leaf ash and determination with high-performance liquid chromatography.

Palm leaf ash was characterized and used as low-cost adsorbent for solid-phase extraction and preconcentration of bisphenol A (BPA) in real water samples. Analysis of BPA was carried out using HPLC involving Eurospher 100-5-C18 (25 cm × 4.5 mm, particle size 5 µm) column and water-acetonitrile (40:60, v/v) as mobile phase. The adsorption was achieved quantitatively at a pH of 6 with elution by 3 mL acetonitrile. The limits of detection and enrichment factor were 0.02 µg L(-1) and 333, respectively. Under optimum conditions the relative standard deviation (RSD) was 2% (n = 10). Comparison of qualification criteria of presented preconcentration procedure with other research indicated that palm leaf ash adsorbent was better than many of the adsorbents in terms of cost and reusability. Also, the limit of detection, precision and enrichment factor were comparable and even better than the previously reported methods. Finally, the efficiency of method was computed by determination of trace amounts of BPA in sea, river, mineral and tap waters with recoveries of 93.3-105.5% and RSDs of 0.61-3.12%.. Briefly, the developed solid-phase extraction and Preparative layer chromatography (PLC) methods may be used for bisphenol A monitoring in any environmental water sample. Copyright © 2016 John Wiley & Sons, Ltd.

A novel sinusoidal design for an electrocoagulation reactor followed by an electro-Fenton reaction and a porous ceramic filter for the treatment of polluted waters.

In this research work, a novel design of an electro-Fenton reactor for the treatment of polluted water was investigated. In addition to the reactor with iron electrodes, a ceramic filter was also used. An electrical circuit was designed to change the cathodes and anodes every 24 s via an electrical relay between the electrodes. The untreated water was sucked into the reactor with an air pump and entered the electrocoagulation chamber after filtration with a ceramic filter. Then, it flows to the polyethylene filter to separate the coagulated particles from the fresh water. To produce 12 L of clean water, the system consumed 100 W of energy. Analysis of a river sample showed a reduction in nephelometric turbidity units (NTUs), total suspended solids (TSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Turbidity reduction studies have shown that the system can improve water transparency by 95%, thereby improving water quality to acceptable levels. Further, this system reduced TSS by more than 86%. In addition, BOD was reduced by more than 84% and COD by more than 88%, as shown by the change in the ratio of BOD to COD from 0.44 to 0.625, indicating improved water quality. According to the results, the treatment system can clean polluted waters, particularly during floods and when industries discharge their effluents into rivers.

Experimental design for the optimization of paraquat removal from aqueous media using a fixed-bed column packed with Pinus Eldarica stalks activated carbon.

In this study, a fixed-bed column packed with an activated carbon (Pinus eldarica stalks (PES-AC)) was used to evaluate the performance of paraquat removal from wastewater. The effect of bed height, initial paraquat concentration, contact time, flow rate on the removal of paraquat was investigated using response surface methodology (RSM) based on central composite design (CCD). From the RSM model, the optimum experimental conditions to achieve 94.65% removal of paraquat were solution pH of 8.0, 6 mg L-1 of paraquat, 4 mL min-1 of flow rate, 0.8 cm of the bed height, and 40 min of contact time. The breakthrough data were significantly fitted with Thomas, bed depth services time (BDST), and Yoon-Nelson models. The high values of NBD (14.33, 32.29, and 54.46 mg L-1) and critical bed depth (0.396, 0.370, and 0.330 cm) obtained from BDST model revealed the high efficiency and suitability of the adsorbent. Adsorption of paraquat on PES-AC was strongly dependent on solution pH, indicating an electrostatic attraction mechanism.

Decorating graphene oxide with zeolitic imidazolate framework (ZIF-8) and pseudo-boehmite offers ultra-high adsorption capacity of diclofenac in hospital effluents.

This study reports on an easy and scalable synthesis method of a novel magnetic nanocomposite (GO/ZIF-8/γ-AlOOH) based on graphene oxide (GO) nanosheets decorated with zeolitic imidazolate framework-8 (ZIF-8), pseudo-boehmite (γ-AlOOH), and iron oxide (Fe3O4) nanoparticles by combining solvothermal and solid-state dispersion (SSD) methods. The nanocomposite was successfully applied to remove of diclofenac sodium (DCF) - a widely used pharmaceutical - from water. Response Surface Methodology (RSM) was used to optimize the adsorption process and assess the interactions among the influencing factors on DCF removal efficiency; including contact time, adsorbent dosage, initial pH, solution temperature, and DCF concentration. Adsorption isotherm results showed a good fitting with the Langmuir isotherm model with an exceptional adsorption capacity value of 2594 mg g-1 at 30 °C, which was highly superior to the previously reported adsorbents. In addition, kinetic and thermodynamic investigations further illustrated that the adsorption process was fast (equilibrium time = 50 min) and endothermic. The regeneration of GO/ZIF-8/γ-AlOOH nanocomposite using acetic acid solution (10% v/v) after a simple magnetic separation was confirmed in five consecutive cycles, which eliminate the usage of organic solvents. The nanocomposite has also shown a superior performance in treating a simulated hospital effluent that contained various pharmaceuticals as well as other organic, and inorganic constituents.

Highly effective pre-concentration of thymol and carvacrol using nano-sized magnetic molecularly imprinted polymer based on experimental design optimization and their trace determination in summer savoury, Origanum majorana and Origanum vulgare extracts.

To ascertain thymol and carvacrol in pharmaceutical syrups, a valid and effective magnetic molecular imprinted polymer dispersive solid phase microextraction (MMIP-DSPME) process was developed in this study, which was in combination with a high performance liquid chromatography-ultra violet (HPLC-UV) technique for the assessment of thymol and carvacrol separation and pre-concentration. Contact time, eluent kind and volume, pH, the mass of the MMIP were all taken into consideration as key factors. Design expert and multi-objective response surface methodology (RSM) were used to optimize these variables. The mass of the MMIP, sample pH, eluent kind, time of sorption, the volume of eluent, and time of elution were 10 mg, 6, acetonitrile, 28 min, 200 µL, and 5.5 min, respectively, for the maximum extraction recovery of the analytes. The limit of detection (LOD) was 0.042 ng mL-1 at the optimal conditions, while the value for the limit of quantification (LOQ) was 0.140 ng mL-1. At the optimized conditions for thymol and carvacrol, the suggested MMIP sorbent had sorption capacities of 64.1 and 72.6 mg g-1, respectively. Furthermore, for triplicate measurements, the linear dynamic range (LDR) was 0.40-5000 ng mL-1, and the method's accuracy (RSD %) was 6.26%. The saturation magnetization for the MMIP was 19.0 emu g-1 obtained by VSM, allowing the sorbent to be separated quickly. The sorption experiments confirmed the large sorption capacity of the MMIP for thymol and carvacrol, as well as its homogeneous binding sites. The extraction recovery for thymol and carvacrol was 96.9-103.8% and 96.6-105.4%, respectively, at all spiked amounts (20, 100, 200, and 500 ng mL-1). The findings of seven desorption-regeneration cycles using MMIP demonstrated the high stability of the sorbent. The MMIP revealed a particular behavior of sorption for thymol and carvacrol, implying a selective, simple, effective, and flexible analytical method.

Synthesis of magnetic tungsten disulfide/carbon nanotubes nanocomposite (WS2/Fe3O4/CNTs-NC) for highly efficient ultrasound-assisted rapid removal of amaranth and brilliant blue FCF hazardous dyes.

In this research, the potentiality of magnetic tungsten disulfide/carbon nanotubes nanocomposite (WS2/Fe3O4/CNTs-NC) as an adsorbent for the ultrasound-assisted removal of amaranth (AM) and brilliant blue FCF (BB FCF) dyes was investigated. The experiments were conducted using a central composite design (CCD) with the inputs of solution pH (X1: 2.0-10), adsorbent mass (X4: 4-20 mg), AM concentration (X2: 10-50 mg L-1), BB FCF concentration (X3: 10-50 mg L-1), and sonication time (X5: 2-12 min). At the optimum conditions, the removal percentages of 99.30% and 98.50% were obtained for AM and BB FCF, respectively. The adsorption of the dyes was described by Langmuir isotherm and pseudo-second-order (PSO) kinetic models. The maximum adsorption capacities of AM and BB FCF were 174.8 mg g-1 and 166.7 mg g-1, respectively. The adsorption thermodynamic study showed that the adsorption of the dyes occurred endothermically and spontaneously. The removal percentages of AM and BB FCF from the real samples were in the range of 94.52-99.65% for the binary solutions. The removal percentage for each dye after five cycles of adsorption/desorption was > 90%. This work provides a useful insight to the potential application of CNTs-based magnetic nanocomposite for the treatment of wastewaters contaminated with dyes.

Encapsulation of rose essential oil using whey protein concentrate-pectin nanocomplexes: Optimization of the effective parameters.

The aim of this study was to optimize the preparation of whey protein concentrate (WPC)-pectin nanocomplexes as a carrier for rose essential oil (REO) via response surface methodology (RSM); with initial concentrations of WPC (4-8%) and pectin (0.5-1%) at different pH values ​​(3-9). The highest encapsulation efficiency of REO was 96.97% for 4.0:0.5 ratio of WPC:pectin at pH = 3. The highest viscosity was obtained at 4:1 ratio of WPC:pectin and pH = 3, and the highest stability (96.5%) was related to 4:1 ratio of WPC:pectin at pH = 9; the lowest stability (81%) was observed at 4:1 ratio of WPC:pectin at pH = 3. Finally, the highest solubility occurred at pH = 9 while the lowest solubility was seen in the treatments prepared at pH = 3 due to the creation of a strong WPC-pectin coacervate complex.

A reusable mesoporous adsorbent for efficient treatment of hazardous triphenylmethane dye wastewater: RSM-CCD optimization and rapid microwave-assisted regeneration.

In this research, mesoporous calcium aluminate nanostructures (meso-CaAl2O4) were synthesized using a citric acid-assisted sol-gel auto-combustion process as the potential adsorbent to eliminate toxic triphenylmethane dye malachite green (MG) from synthetic/real effluent. The surface morphology of meso-CaAl2O4 was highly porous with nanometric size and non-homogeneous surface. The specific surface area, total pore volume, and BJH pore diameter of meso-CaAl2O4 were 148.5 m2 g-1, 1.39 cm3 g-1, and 19 nm, respectively. The meso-CaAl2O4 also showed a very high heat resistance, due to losing only 7.95% of its weight up to 800 °C, which is mainly related to the moisture loss. The optimal adsorption conditions were obtained based on response surface methods (RSM)-central composite design (CCD) techniques. The Langmuir isotherm model was used for fitting the adsorption measurements, which presented 587.5 mg g-1 as the maximum adsorption capacity of the dye. The data obtained from the adsorption kinetics model were found to correspond to the pseudo-second-order model. Also, the thermodynamic parameters including enthalpy change (ΔH°), entropy change (ΔS°), and Gibbs free energy change (ΔG°) indicated that MG dye adsorption by the meso-CaAl2O4 was feasible, endothermic, and occurred spontaneously. Furthermore, the meso-CaAl2O4 was regenerated by microwave irradiation under 900 W at 6 min, and the MG dye removal efficiency was remained over 90% after the five cycles of microwave regeneration.

Treatment of nano-oil polluted wastewater in an expanded bed adsorption column based on carboxymethyl cellulose-cellulose-nickel composite beads.

In the present work, spherical carboxymethyl cellulose-cellulose-nickel (CMC-C-Ni) composite beads as novel adsorbent was synthesized to make a stable expanded bed adsorption (EBA) column for the treatment of the oily wastewater collected from the downstream of rapeseed industry. The morphology and structure of the CMC-C-Ni composite beads were studied by scanning electron microscopy (SEM) and optical microscope. The SEM images revealed that the synthesized composite beads were spherical with porous structure. The pore size of the beads was in the range of 90-200 nm. The physical characteristics of the CMC-C-Ni composite beads including wet density, porosity, and water content were respectively in the ranges of 1.23-1.63 g/cm3, 82.29-90.75%, and 52-76%. The factor of bed expansion in the range of 2-3 was corresponded with Richardson-Zaki equation. The results showed that by increasing the fluid viscosity, the terminal settling velocity (Ut) was reduced. The expansion index values were between 2.77 and 3.14 that were close to 4.8 (commonly utilized index in the laminar flow regimes). CMC-C-Ni composite beads were tested when the velocity of fluid was ˂ 700 cm/h, and the Daxl was found to be ˂ 1 × 10-5 m2/s (steady state).

Ultrasound-assisted solid phase microextraction-HPLC method based on Fe3O4@SiO2-NH2-molecularly imprinted polymer magnetic nano-sorbent for rapid and efficient extraction of harmaline from Peganum harmala extract.

In the present study, a magnetic molecularly imprinted polymer (MMIP) was synthesized for the extraction of harmaline from Peganum harmala by dispersive solid-phase microextraction (DSPME). The MMIP for selective and intelligent extraction of harmaline with excellent functionality and high selectivity was synthesized using the sol-gel method with functionalized superparamagnetic core-shell nanoparticles, ethylene glycol dimethacrylate (EDMA) as a cross-linker, methacrylic acid (MAA) as a functional monomer, and 2,2-azobisisobutyronitrile (AIBN) as a porogen. To study the properties and morphology of the coated polymer, FT-IR spectroscopy, FESEM, TEM images, and VSM were used. The DSPME-HPLC-UV equipment was used to quantify and analyze the data obtained from harmaline extraction. In this research, the efficiency of the synthesized polymer in harmaline extraction was modeled and optimized using the response surface methodology based on central composite design (RSM-CCD). In addition, for modeling the isotherm of harmaline sorption by the MMIP, Langmuir and Freundlich isotherm equations were used. The obtained results showed that the extraction of harmaline with the MMIP was well described with Freundlich isotherm. The results of the validation of the method showed that the measurement of harmaline in the concentration range of 1.0-4000 ng mL-1 followed a linear relationship (R2 = 9986.0). Moreover, the accuracy or repeatability index (% RSD) was determined to be < 10, and the LOQ and LOD values were 0.526 and 0.158 ng mL-1, respectively. The results of this study showed that the DSPME technique by using the synthesized MMIP as an effective sorbent with high efficiency and capacity could be utilized for pre-concentration and extraction of harmaline from real and complex samples.

Nano-sized Fe3O4@SiO2-molecular imprinted polymer as a sorbent for dispersive solid-phase microextraction of melatonin in the methanolic extract of Portulaca oleracea, biological, and water samples.

In this study, a magnetic molecularly imprinted polymer (MMIP (Fe3O4@SiO2-MIP)) was used for the dispersive magnetic solid-phase microextraction (d-MSP-µ-E) to design an easy and effective method for melatonin (MLT) extraction in the methanolic extract of Portulaca oleracea, human urine and plasma, and water samples. HPLC with UV detection was utilized, and pH, the type and volume of eluent, MMIP mass, and contact time were considered as effective factors in the study of MLT separation and pre-concentration. These factors were optimized by Plackett-Burman and multi-objective response surface methodology (RSM). The values were 10 mg, 14 min, 4.2, methanol, 0.180 mL, 2.5 min, for the MMIP mass, time of sorption, sample pH, eluent type, eluent volume, and time of elution, respectively. At the optimum conditions, the limit of detection (LOD) was 0.046 ng mL-1, and the limit of quantification (LOQ) was 0.156 ng mL-1. The sorption capacity of the proposed MMIP sorbent was 109.1 mg g-1 at the optimum conditions. Besides, linear dynamic range (LDR) was 0.2-4200 ng mL-1, and the precision of the method (RSD %) for triplicate measurements was <6.1%. The MMIP showed saturation magnetization of 19.75 emu g-1, resulting in fast separation of the sorbent. The sorption test revealed the high sorption capacity of the MMIP for MLT and its homogeneous binding sites. In all spiked levels (50, 100, 200, and 500 ng mL-1), 93.07-104.1% was the range obtained for the recovery of MLT. The relative selectivity factor (ß) values of MLT/tryptophan, MLT/serotonin, MLT/ferulic acid, MLT/mefenamic acid, MLT/quercetin, MLT/luteolin, and MLT/chlorogenic acid were 1.60, 1.68, 2.02, 2.38, 2.32, 2.40, and 2.50, respectively. The results of desorption-regeneration cycles (seven times) by employing the MMIP showed the high stability of the resultant material. In conclusion, the MMIP combined with the magnetic separation showed a specific sorption behavior for MLT and suggested a simple, flexible, selective, and powerful analytical tool.

A new approach for microextraction of trace albendazole sulfoxide drug from the samples of human plasma and urine, and water by the molecularly imprinted polymer nanoparticles combined with HPLC.

In this research study, a method of dispersive-micro-solid phase extraction (D-µ-SPE) combined with molecularly imprinted polymer nanoparticles (MIP-NPs) with HPLC-UV was developed for the fast and selective detection of the trace amount of albendazole sulfoxide (ABZSO) in the biological samples. To investigate the effective factors on ABZSO microextraction by the method, central composite design (CCD) was utilized, and the optimum conditions for ABZSO microextraction were sample pH of 8.0, MIP-mass of 15 mg, sonication time of 12 min, and eluent (methanol) volume of 0.25 mL. Under the obtained optimal extraction conditions, the value for the limit of detection (LOD) and limit of quantification (LOQ) was respectively showed to be 0.074 and 0.246 ng mL-1. In addition, the calculated peak areas exhibited a linear relationship with the ABZSO concentration ranging from 0.4 to 4200 ng mL-1. The analyses of the samples including human plasma and urine, and water were successfully performed by the usage of the D-µ-SPE method, which was a simple and sensitive technique and a suitable alternative for the analysis of ABZSO. In the analysis of ABZSO in various samples, the recoveries at various levels of ABZSO concentrations (50, 300, and 500 ng mL-1) were in the range of 95.7-103.0 %, and the relative standard deviations (RSDs; n = 3) varied from 2.2 to 4.4%.

Response surface methodology based on central composite design for simultaneous adsorption of rare earth elements using nanoporous calcium alginate/carboxymethyl chitosan microbiocomposite powder containing Ni0.2Zn0.2Fe2.6O4 magnetic nanoparticles: Batch and column studies.

In this research paper, the utilization of the magnetic calcium alginate/carboxymethyl chitosan/Ni0.2Zn0.2Fe2.6O4 (CA/CMC/Ni0.2Zn0.2Fe2.6O4) was investigated for the simultaneous aqueous adsorption of Nd (III), Tb (III), and Dy (III). The magnetic products were characterized by FE-SEM, EDX, XRD, FT-IR, TGA, and VSM techniques. The saturation magnetization value for Ni0.2Zn0.2Fe2.6O4 and CA/CMC/Ni0.2Zn0.2Fe2.6O4 was found to be 45.87 and 14.14 emu/g, respectively. Using RSM, a quadratic polynomial equation was obtained to predict the adsorption efficiency of each ion. Under the conditions of pH = 5.5, adsorbent dosage of 0.1 g, initial concentration of 30 mg/L, and contact time of 53 min predicted by RSM, the adsorption efficiencies of Nd (III), Tb (III), and Dy (III) were respectively 95.72, 96.17, and 99.44%. The isotherm and kinetic data were respectively fitted well with Freundlich and pseudo-second-order (PSO) models. The desorption of the loaded ions was effectively carried out by 0.2 M HNO3, and the adsorbent was consecutively utilized with 2.54, 1.63, and 1.16% decrease in adsorption efficiency for Nd (III), Tb (III), and Dy (III), respectively, after the forth cycle. Additionally, the adsorption behavior of the CA/CMC/Ni0.2Zn0.2Fe2.6O4 towards Nd (III), Tb (III), and Dy (III) was studied by using a fixed-bed column technique.

Modeling and optimization of ultrasound-assisted high performance adsorption of Basic Fuchsin by starch-capped zinc selenide nanoparticles/AC as a novel composite using response surface methodology.

In this study, the starch-capped zinc selenide nanoparticles loaded on activated carbon (ST-Zn-Se-NPs-AC) composite was fabricated, and then it was used for removing Basic Fuchsin (BF) dye from aqueous solution. The ST-Zn-Se-NPs-AC composite was characterized by FE-SEM, UV-Vis, EDS, and XRD techniques. The removal percentage dependence to different variables such as initial BF concentration, pH, dosage of adsorbent, and time of sonication was investigated by Central Composite Design (CCD) under Response Surface Methodology (RSM). The quadratic model between the independent and dependent variables was predicted. A good agreement between the experimental and predicted data was achieved by the predicted model that showed the performance of the predicted model for predicting of real optimum points, and it was successfully employed to remove BF from aqueous media. The maximum removal percentage of 99.34% was obtained by the predicted model under the optimum conditions (15 mg L-1 of initial BF concentration, pH of 7.0, 12 mg of ST-Zn-Se-NPs-AC, and 6 min of sonication time), which was very close to the experimental value (99.00%). Moreover, the data were efficiently fitted by Langmuir model, and the saturation adsorption capacity (Qmax) at 25 °C for BF was discovered to be 222.72 mg g-1.

Biocompatible chitosan-zinc oxide nanocomposite based dispersive micro-solid phase extraction coupled with HPLC-UV for the determination of rosmarinic acid in the extracts of medical plants and water sample.

In the present research, a procedure was described for the recovery of rosmarinic acid (RA) from medical extract samples using chitosan­zinc oxide nanoparticles as a biocompatible nanocomposite (CS-ZnO-NC). The dispersive micro-solid phase extraction (D-µ-SPE) of RA from the medical extract samples was investigated by using the prepared biocompatible composite as a solid phase. The HPLC-UV method was used for measuring the extracted RA. The important variables (pH, biocompatible composite mass, contact time, and volume of eluent) associated with the extraction process were analyzed by the application of central composite design (CCD). The achieved optimum values for the mentioned variables were 7.0, 10 mg, 4 min, and 180 µL, respectively. The extraction recovery (99.68%) obtained from the predicted model was in agreement with the experimental data (98.22 ± 1.33%). In addition, under the obtained optimum conditions and over the concentration in the range of 2-3500 ng mL-1, a linear calibration curve was obtained with R2 > 0.993. The limit of detection (LOD) and quantification (LOQ) values were computed, and the obtained ranges were respectively from 0.060 to 0.089 ng mL-1 and 0.201 to 0.297 ng mL-1. In addition, the enrichment factors were obtained in the range of 93.7-110.5 with preconcentration factor of 83.3. Therefore, the D-µ-SPE-HPLC-UV method could be used for analyzing RA in the samples of the extracts obtained from the medical plants and water with the recovery values of the analyte in the range of 96.6%-105.4% and the precision with relative standard deviation <5.7%.

Synthesis of poly(acrylamide-co-itaconic acid)/MWCNTs superabsorbent hydrogel nanocomposite by ultrasound-assisted technique: Swelling behavior and Pb (II) adsorption capacity.

In this research, the poly (acrylamide-co-itaconic acid)/multi-walled carbon nanotubes (P(AAm-co-IA)/MWCNTs) as a novel superabsorbent hydrogel nanocomposite was synthesized by graft copolymerization of acrylamide (AAm) and itaconic acid (IA) mixture in the presence of the MWCNTs using ammonium persulfate (APS) as a free radical initiator and methylenebisacrylamide (MBA) as a crosslinker under ultrasound-assisted condition. The blank P(AAm-co-IA) hydrogel and its composite with the MWCNTs were characterized by means of SEM, FTIR, XRD and TGA methods. The effects of different parameters such as pH, time, the MWCNTs content and salt solutions on swelling behavior were investigated. The stability of the hydrogel increased by any increase in the MWCNTs content, which might be attributed to the hydrophobic nature of the MWCNTs as well as the increase of the crosslinker density. The water retention capacity (WRC) of the P(AAm-co-IA) hydrogel increased in the presence of the MWCNT (10 wt%). The synthesized hydrogel nanocomposite was studied for Pb (II) adsorption from aqueous solution. The effects of different parameters such as contact time (5-90 min), Pb (II) initial concentration (25-175 mg/L) and initial pH (1.5-4.5) of solution on Pb (II) adsorption were investigated by batch method. In comparison to P(AAm-co-IA) hydrogel, the P(AAm-co-IA)/MWCNTs hydrogel nanocompoite showed better adsorption behavior toward Pb (II). One of the most important aspects of this research was to investigate the effects of ultrasonic waves on polymer matrix and its ability.