This paper deals with the removal of textile dyes from aqueous solutions by a poly(propylene imine) dendrimer (PPI) as a polymeric nanoarchitecture in single and binary (mixture of dyes) systems. Direct Blue 78 (DB78) and Acid Black 26 (AB26) were used as model dyes. The effects of operational parameters such as dendrimer concentration, contact time, dye concentration, inorganic anions (salts), and pH have been studied on dye removal. Adsorption isotherms (Langmuir, Freundlich, and Tempkin models), adsorption kinetics (pseudofirst order, pseudosecond order, and intraparticle diffusion), and dye desorption were studied in single and binary dye systems. It was found that the isotherm data of DB78 and AB26 in single and binary systems of dyes followed the Langmuir isotherm. Adsorption kinetics of dyes in single and binary dye systems were found to conform to a pseudosecond order model. Desorption tests showed that the maximum dye releases of 93 % for DB78 and 86 % for AB26 in a single system and 90 % for DB78 and 84 % for AB26 in a binary system of dyes were achieved in aqueous solution at pH 12. On the basis of the data of the present study, it can be concluded that the dendrimer as a polymeric nanoarchitecture is an eco-friendly adsorbent with a relatively large adsorption capacity and may be a suitable alternative for elimination of dyes from aqueous media.
not Available.
Herein, zeolitic imidazolate framework (ZIF-8) - Polyvinylpyrrolidone (PVP) - Polyethersulfone (PES) composites (ZPP) with different amounts of ZIF-8 (1%, 2% and 3% denoted as ZPP-1, ZPP-2 and ZPP-3, respectively) were prepared. ZIF-8 particles have been synthesized individually. Then they are mixed with PES and PVP/PES and converted into membrane films. The materials including ZIF-8, PES, PVP/PES, ZPP-1, ZPP-2 and ZPP-3 were characterized by FTIR, XRD, AFM, SEM, BET, TEM, contact angle, and optical microscopy. The prepared membrane was used to remove Malachite green (MG) using a cross flow system. The outcomes showed that the ZPP hybrid membrane had higher dye removal ability. The membrane is made in an optimum state of 99.6% of the Malachite green (MG) removal from the wastewater at a flow rate of 12.42 L/m2 h. These results indicate that the ZPP membrane prepared in this way without the need for any special preparation can be a good option for the dye removal process. The prepared membranes have good efficiency and stability under different operating pressures.
In this paper, reduced graphene oxide (rGO) nanosheet from graphite was synthesized using the top‐down approach. The surface of rGO was modified by cetyltrimethylammonium bromide (CTAB) to prepare rGO/CTAB adsorbent for anionic dye removal. The prepared rGO/CTAB was characterized by XRD, FTIR, FE‐SEM and TGA. The operation parameters (surfactant concentration, adsorbent dosage, pH and initial concentration of dye solution) affecting the batch adsorption process to remove direct red 80 (DR80) and direct red 23 (DR23) were studied in detail. The dye adsorption capacity of rGO/CTAB was 213 and 79 mg/g for DR80 and DR23, respectively. In addition, dye removal followed the Langmuir isotherm with pseudo‐second order reaction kinetics.
This paper investigates the ability of multi-walled carbon nanotube (CNT) to adsorb three cationic dyes from colored wastewater in single and binary systems. Basic Blue 41 (BB41), Basic Red 18 (BR18), and Basic Violet 16 (BV16) were used as model dyes. The surface characteristic of CNT was studied using Fourier transform infrared. The effect of operational parameters (CNT dosage, dye concentration, pH, and salt) on dye removal was investigated. The adsorption isotherm and kinetic were studied. The isotherm data in single and binary systems followed Langmuir isotherm. The maximum adsorption capacity (Q0) of BB41, BR18, and BV16 in single dye systems were 123.457, 80.012, and 64.935 mg/g, respectively. In adsorption from binary dye solutions, the isotherm of each individual dye followed extended Langmuir isotherm model. The paper also measured the kinetic adsorption of the dyes on CNT in single and binary dye systems at different dye concentrations. The adsorption follows a pseudo-second-order kinetic model at all the concentrations and values on the rate constants (k2) in binary systems at optimum dye concentration (25 mg/L) have been calculated as 0.612, 0.548, and 0.517 g/mg min, respectively. Results showed CNT was an effective adsorbent to remove cationic dyes from single and binary systems.
Herein, the novel green MOF's nanocomposite based on cucumber peel activated carbon (AC) and chromium-based metal-organic framework (MIL-101(Cr)) with different AC ratios (2, 5 and 10 wt%) was synthesized and used for removing Acid Green 25 (AG25) and Reactive Yellow 186 (RY186) dyes from the binary systems. The characterization of materials was done using TGA, BET, XRD, SEM, and FTIR. The SEM images of MIL-101 showed octahedral crystal structure and composite materials exhibited the same morphology as MIL-101(Cr) crystals on an activated carbon bed. The BET surface area of AC and AC/MIL-101(Cr)_5% was measured 1096.83 and 2412.1 m2/g, respectively. The results showed that the Response Surface Methodology (RSM) model predicted the actual data with high correctness. The reliability of the RSM model was validated by the high values of R2 (AG25: 0.961 and RY186: 0.957). The obtained data from this research are well-fitted with the Langmuir isotherm and the pseudo-second order kinetics. The desorption process indicates that the adsorption capacity changes are <9% after five cycles.
Herein, magnetic metal-organic framework nanocomposite (ZIF-8@SiO2@MnFe2O4) was synthesized. The ultrasound-assisted simultaneous adsorption of Malachite Green (MG) and Methyl Orange (MO) as cationic and anionic dyes onto ZIF-8@SiO2@MnFe2O4 magnetic microporous nanocomposite (MMNC) as a novel adsorbent was investigated. The FTIR, FESEM, TEM, XRD, BET and VSM were used to characterize the prepared adsorbent. The analysis of dyes concentration in a binary mixture was investigated using zero-order and first order derivative spectrophotometry. The individual effects and possible interactions between the various parameters were investigated by response surface methodology (RSM). The optimized values of sonication time, adsorbent mass, MG and MO concentrations were found to be 15 min, 0.005 g, 13 and 10 mg L−1, respectively. The removal percentages for MG and MO were predicted to be 92.5% and 5.9%, respectively. The data matched well with pseudo-second order kinetic model and Langmuir isotherm models. The maximum adsorption capacities were obtained 1010.2 and 78.12 mg g−1 for MG and MO dyes, respectively. Moreover, the magnetic nanocomposite showed that it could selectively adsorbed cationic MG dye from the MG/MO mixture. After reaction, the magnetic adsorbent can be easily separated from the mixture via an external magnetic field and can be effectively regenerated.
The effect of chain length compatibility on corrosion inhibition effect of mixed inhibitor systems of cationic gemini surfactant (l,3-butan-bis(dodecyl dimethyl ammonium bromide) (designated as 12-4-12)), nonionic co-surfactants (C7OH (1-heptanol), C12OH (1-dodecanol) and C15OH (1-pentadecanol)) on low carbon steel in acidic medium was studied using weight loss, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. Data represented that the corrosion rate decreased by increasing surfactant concentration. In addition, less chain length difference causes more compatibility and inhibition efficiency on behavior of surfactant and co-surfactant mixture. Increasing of inhibition efficiency for C12OH+gemini surfactant was more than other mixtures.
In this paper, nickel–zinc ferrite magnetic nanoparticle (NZFMN) was synthesized and its dye degradation ability using photocatalytic ozonation was investigated. The NZFMN was characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM), Fourier transforms infrared (FTIR) and alternative gradient force magnetometer (AGFM). Reactive Red 198 (RR198) and Direct Green 6 (DG6) were used as dye models. UV–vis and ion chromatography (IC) analyses were employed to study dye degradation. The effects of operational parameters on decolorization such as NZFMN dosage, dye concentration, salt and pH were studied. RR198 and DG6 were completely decolorized (100%) by photocatalytic ozonation using NZFMN. Formate, acetate and oxalate anions were detected as dominant aliphatic intermediates. Nitrate, sulfate and chloride ions were detected as mineralization products of dyes. Results showed that the photocatalytic ozonation using NZFMN was a very effective method for dye degradation.
not Available.
In this paper, titania/silica nano-hybrid (TSNH) and amine-functionalized titania/silica nano-hybrid (AFTSNH) (LAFTSNH: low amine-functionalized titania/silica nano-hybrid and HAFTSNH: high amine-functionalized titania/silica nano-hybrid) were synthesized and their dye removal abilities were investigated. Physical characteristics of adsorbents were studied using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). Reactive Red 198 (RR198) and Acid Red 14 (AR14) were used as model compounds. The kinetic and isotherm of dye adsorption were studied. The effects of operational parameters such as adsorbent dosage, initial dye concentration, pH and salt on dye removal were evaluated. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetics. The maximum dye adsorption capacity (Q 0) of TSNH, LAFTSNH and HAFTSNH were 0.027, 116.279 and 138.889mg/g for RR198 and 0.232, 270.270 and 315.500mg/g for AR14, respectively. Dye adsorption onto TSNH, LAFTSNH and HAFTSNH for both dyes followed with Langmuir, Freundlich and Langmuir isotherms, respectively. The results showed that the AFTSNH as an adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored wastewater.
In this paper, nanoporous polyacrylonitrile/calcium carbonate (PAN/CaCO3) nanofiber was produced through a solvent casting/porogen leaching technique. Calcium carbonate (CaCO3) nanoparticle was extracted from PAN/CaCO3 nanofiber. The nanofiber was modified using triethylenetetriamine (TETA). The aminated nanoporous PAN (ANPAN) nanofiber was characterized by FTIR, SEM, AFM and DSC. The dye removal ability of ANPAN nanofiber from wastewater was investigated by studying the influence of adsorbent dosage, dye concentration, and solution pH on dye adsorption. Response surface methodology (RSM) was used to build up the equation of dye removal efficiency from water with respect to operational conditions (adsorbent dosage, pH and dye concentration). The dye removal isotherm and kinetics followed the Langmuir isotherm and pseudo-second order model respectively. The thermodynamic data indicated dye removal by ANPAN nanofiber was spontaneous, endothermic, and a physisorption reaction. The RSM data confirmed good agreements with the experimental results.
Ultrasound-assisted procedure is widely used for synthesizing materials due to its low cost, environmental friendly, facile, and mild properties. Herein, ultrasound-assisted synthesis of magnetic zeolitic imidazolate framework-8 (ZIF-8)/cobalt ferrite (CoFe2O4)/graphene oxide (GO) nanocomposites (ZIF-8/CoFe2O4/GO: ZCG) with different amounts of CoFe2O4/GO (25 and 50 mg denoted as ZCG-25, and ZCG-50) were studied in details. The GO was prepared from graphite. The synthesized materials including GO, ZIF-8, CoFe2O4, CoFe2O4/GO, ZCG-25, and ZCG-50 were fully characterized using BET, TEM, XRD, SEM, FTIR, and VSM. The ultrasound-assisted pollutant removal ability of the synthesized materials was investigated using Malachite Green (MG) as a model contaminant. The surface area of GO, CoFe2O4, ZCG-25, and ZCG-50 was 46, 52, 1543, and 2490 m2/g, respectively. Pollutant removal obeyed the pseudo-second order and Langmuir models. The pollutant removal capacity of ZCG-50, ZCG-25, CoFe2O4/GO, ZIF-8, CoFe2O4 and GO was 2610, 1948, 212, 901, 100, and 118 mg/g, respectively.
Novel chitosan-tailored graphene oxide (CSGO)-embedded poly(ether-b-amide) (PEBA) thin film nanocomposite (TFN) membranes have been fabricated and coated on ultraporous polyethersulfone. To synthesize the nature-friendly CSGOs, the covalent functionalization of GO has been done by carbohydrate polymer chitosan. The green nanofillers were then incorporated in the PEBA selective layer at different loadings up to 2 wt%. The structural studies were performed using FTIR, XRD, SEM, AFM and contact angle analyses, which confirmed the appropriate filler dispersion and enhanced hydrophilicity of the TFN membranes. Moreover, using nanofiltration (NF) for malachite green (MG) dye rejection, the effects of CSGO loadings, transmembrane pressure, feed concentration and duration on the membranes separation performance were also assessed. The membrane loaded with 0.1 wt% of CSGO showed the highest permeate flux, 3.2 times higher than that of the TFC membrane. The surface-decorated CSGO-filled TFN membranes also represented improved antifouling performance because the CSGO nanofillers had a positive charge due to the protonation of chitosan N-H groups in the acidic medium of this work.
In this paper, cobalt ferrite magnetic nanoparticle was modified by N-(2-aminoethyl)-3-(trimethoxysilyl) propyl amine. Polyoxometalate was immobilized on the modified bi-amino surface functionalized nanoparticle to prepare the environmentally friendly catalyst nanoparticle (EFCN). The synthesized EFCN was characterized using Fourier transform infrared, scanning electron microscopy and X-ray powder diffraction. The EFCN was used for photocatalytic dye degradation. Acid Red 18 and Direct Red 81 were used as model dyes. The effect of catalyst dosage, dye concentration and salt on dye degradation was studied. Dye degradation increases by catalyst dosage. The results showed that decolorization followed a zero-order kinetic model.
