In this paper, silica nanoparticle (SN) and amine-functionalized silica nanoparticle (AFSN) were prepared and their dye removal abilities were investigated. Physical characteristics of adsorbents were studied using the point of zero charge, surface area, Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). Three textile dyes, Acid Red 14 (AR14), Acid Black 1 (AB1) and Acid Blue 25 (AB25), were used as model compounds. The effect of operational parameter such as adsorbent dosage, pH, dye concentration and salt were evaluated. The isotherm and kinetic of dye adsorption were studied. The maximum dye adsorption capacity (Q 0 ) of SN for AR14, AB1 and AB25 was 0.031mg/g, 0.034mg/g and 0.170mg/g, respectively. But the maximum dye adsorption capacity of AFSN for AR14, AB1 and AB25 was 434mg/g, 250mg/g and 167mg/g, respectively. It was found that dye adsorption onto SN and AFSN followed with Freundlich and Langmuir isotherms, respectively. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetics. Based on the data of present investigation, one could conclude that the AFSN being an eco-friendly adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored aqueous solutions.
Corrosion inhibition effect of cationic surfactant DTAB (Dodecyl Threemethyl Ammonium Bromide) on low carbon steel in 1M HCl was studied using weight loss and OCP (Open Circuit Potential) methods. Inhibition efficiency increases with increasing of surfactant concentration. Also synergistic effect between surfactant and different alkaline metals salts (KCl, NaCl, NaBr, NaI, LiCl, Na2SO4, and NaNO3) in 1 M HCl is investigated. The effect of different anions and different metal cations on inhibition efficiency is discussed. The inhibition efficiency increases with increasing of salts concentration and reaches the maximum value near 0.1 M. The results show that the synergistic effects of salts are in this order Na2SO4 >NaI > LiCl > NaCl > KCl > NaBr > NaNO3. This inhibitor system containing cationic surfactant and an alkaline metal salt is efficient and low-cast for steel corrosion inhibition in HCl medium, even when the concentration of DTAB is as low as 0.5 × 10-4 M.
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Herein, Fe based metal-organic framework (Materials Institute Lavoisier: MIL100) and its nanocomposites with different titania nanofiber (TNF) amounts (0.05, 0.07 and 0.09 g denoted as MIL100/TNF5, MIL100/TNF7 and MIL100/TNF9) were synthesized using a facile and green procedure at room temperature and atmospheric pressure. The TNF inorganic nanofiber was synthesized using the electrospinning method. The nanomaterials were fully characterized. They were used for visible-light photocatalytic degradation of Methylene Blue (MB). The surface area of MIL100/TNF7 was 1194.48 m2/g. The data indicated the MIL100 diameters ranging from 22 to 72 nm. The decolorization percentage of the synthesized materials at different dosages including 0.003, 0.004, 0.005, and 0.006 g was 39.80, 54.96, 63.31, and 72.10% for MIL100, 25.50, 26.81, 29.23, and 35.62% for TNF and 46.42, 70.85, 88.3, 97.96 and 99.40% for MIL100/TNF7, respectively. The MIL100/TNF7 nanomaterial had higher dye degradation ability, reusability, and stability over five cycles. Dye degradation followed first-order kinetics.
In this article, surface modification of feldspar using hexadecyltrimethyl ammonium bromide (HDTMA) and its dye removal ability in single and binary systems was studied. Acid Black 1 (AB1) and Acid Red 14 (AR14) were used as model dyes. The monocomponent Langmuir isotherm model was applied to experimental data and the isotherm constants were calculated for both dyes. The monolayer coverage capacities of surfactant‐modified feldspar (HDTMA‐feldspar) for AB1 and AR14 dyes in single solution system were found as 6.369 mg/g and 3.984 mg/g, respectively. It was observed that the equilibrium uptake amounts of AB1 and AR14 dye in binary mixture onto sorbent decreased with increasing concentrations of the other dye resulting in their antagonistic effect. Equilibrium adsorption for binary systems was analyzed by using the Extended Langmuir and Jain and Snoeyink Modified Extended Langmuir models. The rate of kinetic processes of single and binary dye systems onto adsorbent was described by using two kinetics adsorption models. The pseudo‐second‐order model was the best choice among the kinetic models to describe the adsorption behavior of single and binary dyes onto HDTMA‐feldspar. Thermodynamic parameters showed that dye adsorption on HDTMA‐feldspar were exothermic and unspontaneous in nature. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
This paper deals with the degradation of Fenitrothion (an agricultural organophosphorous pollutant) in aqueous solution by titania nanophotocatalysis. The immersion type method was used for the treatment of polluted water. UV-Vis, ion chromatography and chemical oxygen demand analyses were employed to obtain the details of the photocatalytic degradation and mineralization of Fenitrothion. The numerical model was used to solve mathematical equation describing pollutant degradation process. The simulation results were compared to those results obtained from experimental tests and close agreement was achieved. Results show that the immobilized titania nanophotocatalysis is the effective method for removing Fenitrothion from contaminated water.
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.
To overcome the limitations of current water treatment technologies, it is essential to develop non-toxic materials with high removal capabilities. Herein, novel green biocomposite beads, CS/ZIF-8/TiO2 (CZT), based on chitosan modified with zeolitic imidazolate framework (ZIF-8) and titania (TiO2) was introduced. The interesting and noteworthy features of this new biocomposite are its green synthesis, biocompatibility, and easy separation ability. The composite beads effectively decolorize Malachite Green (MG) dye solution using visible LED light. In the present study, the efficiency of three components of CZT biocomposite, which were synthesized by two different methods (in situ and blending), was compared to investigate the effect of the synthesis method, as well as the synthesis with two different amounts of TiO2 (0.2 g, and 0.4 g) to investigate the effect of TiO2. The prepared materials through the XRD, SEM, EDS, FTIR, DRS, TGA, and RAMAN analyses were characterized. The synergistic effect of ZIF-8, TiO2, and chitosan in the biocomposite increased the photo-decolorization ability of the MG dye under visible-light irradiation. The decolorization at the optimum pH (pH = 6.5) after 180 min reached 94.5% and at the natural pH (pH = 3.93) after 300 min reached 98.2%. The photocatalytic decolorization reaction of the biocomposite followed zero-order kinetics.
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.
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.
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In this work, magnetic nanoparticles of ZIF-8/NiFe2O4 were synthesized using a simple method to employ the photocatalytic activity under visible-light irradiation for the degradation of methylene blue. The ZIF-8/NiFe2O4 photocatalyst with 30 wt.% of NiFe2O4 demonstrated the best photocatalytic performance with a degradation efficiency of 94% in 120 min and the stability was good after 4 cycles. The ZIF-8/NiFe2O4 composite could easily separate from the water environment by an external magnet. The present study would open a new horizon for highly efficient visible-light photocatalysts for the degradation of organic dyes in wastewater.
No abstract is provided for this article.
Degumming is a surface modification process of natural fibers such as silk. In this paper, the feasibility of degumming with ultrasonic, ultrasonic–soap, and ultrasonic–enzyme (alcalase, savinase, and mixtures of these enzymes) processes as cleaner and environmentally friendly surface modification techniques of Persian silk were investigated. The effectiveness of parameters such as sonication time, soap, ultrasound–enzyme, enzyme concentration, degumming time and enzymes mixture on silk degumming were studied. The evaluation of the data was carried out through the measurement of the weight loss, strength, and elongation of the samples. In addition, the enzymatic treatment improved the properties of silk yarn such as strength and elongation. The scanning electron microscope images were obtained for degummed silk samples. The findings of this research support the potential production of new environmentally friendly textile fibers.
No abstract is provided for this article.
