The aim of our research was to study the ability of CuO nanoparticle which was synthesized for photocatalytic dye degradation of Direct Red 31 (DR31), Reactive Red 194 (RR194) and Reactive Red 120 (RR120) and to apply response surface methodology (RSM) and genetic algorithm (GA) in the optimization of the process.The characteristics of the nanoparticle were investigated by XRD, SEM and FTIR.The experiments were analyzed using response surface methodology and genetic algorithm.A Historical Data Design was used to evaluate the effects and interactions of the four significant variables: catalyst dosage, dye concentration, reaction time and salt (inorganic anion) on the photocatalytic degradation of dyes as the process response.All the experimental data showed the good agreement with the predicted results according to RSM and GA optimizations.Under the optimized conditions (catalyst dosage, 0.005 g; dye concentration, 50 mg/L; reaction time, 180 min and inorganic anion, blank) the maximal decolorization efficiencies of 78.25% , 80.08% and 70.14% were achieved for DR31, RR194 and RR120 respectively.
Corrosion inhibition effect of cationic surfactants, DTAB (Dodecyl Three methyl Ammonium Bromide) and TTAB (Tetradecyl Three methyl Ammonium Bromide) on low carbon steel was studied using weight loss, Open circuit potentional (OCP) and Electrochemical Impedance Spectroscopy (EIS) measurements. The effect of chain length compatibility on corrosion inhabitancy of surfactant and co-surfactant was investigated by C7OH (1-heptanol), C12OH (1-dodecanol) and C15OH (1-pentadecanol) as nonionic co-surfactants in acidic media at different concentrations of DTAB and TTAB. Data represented that the corrosion rate decreased by increasing concentration of DTAB and TTAB, independently. The effect of chain length compatibility on surfactant behavior was discussed. Decreasing of corrosion rate for DTAB+C12OH was more pronounced than other mixtures.
Herein, MIL-53 (Fe) and MIL-53 (Fe)/graphene oxide (GO) nanocomposite were synthesized and denoted as MIL-C, and MIL-C/GO. The synthesized materials were modified using 3-amino propyl trimethoxy silane (APTMS) (amine-functionalization) with different amounts (0.1, 0.2, and 0.3 mL for preparing MIL-C/NH2(0.1), MIL-C/NH2(0.2), and MIL-C/NH2(0.3), MIL-C/GO-NH2(0.1), MIL-C/GO-NH2(0.2), and MIL C/GO-NH2(0.3), respectively) and characterized. Direct Red 23 (DR23) was used as a model pollutant. The dye adsorption followed a Langmuir isotherm and pseudo-second-order model. The MIL-C/GO and MIL-C/GO-NH2(0.3) showed the adsorption capacity of 1,371 and 4,504 mg/g, respectively. The high removal ability and reusability indicated that the synthesized MIL-C/GO-NH2(0.3) could be as an alternative adsorbent for other organic contaminant with similar chemical structures from aqueous media.
Herein, NH2-MIL-125(Ti) (NMT) as one of the known stable metal-organic frameworks (MOFs) in aqueous solution was successfully magnetized with CoFe2O4 nanoparticles through the hydrothermal method. The Ag/AgCl as a plasmonic photocatalyst was assembled on the CoFe2O4/NMT (CFNMT) at room temperature by in situ deposition, and photo-reduction methods to improve the photocatalytic activity of CFNMT under LED visible light. The prepared materials were fully characterized by SEM/EDX, TEM, FTIR, XRD, UV-DRS, and VSM analysis. Rhodamin B (RhB) was selected as the pollutant model. The results showed that the Ag/AgCl@CFNMT had super-fast degradation ability of RhB molecule due to the synergetic effect between Ag/AgCl and CFNMT in comparison with NMT and CFNMT. The introduced Ag/AgCl on the surface of CFNMT increased absorption of photons in the visible region and enhanced the transfer and separation of the produced charge on the contact area between Ag/AgCl and CFNMT. Also, after seven times recycling, besides the simple magnetic separation of Ag/AgCl@CFNMT from liquid media, the composite still showed high photodegradation ability (89%).
Zinc aluminum hydroxide (ZAH) as a porous adsorbent was synthesized using microwave assisted combustion method and its dye removal ability from single and binary systems was studied. The ZAH characteristics were investigated using XRD, FTIR, and SEM. Acid Blue 92(AB92), Acid Red 14 (AR14), and Direct Red 23 (DR23) were used. The effect of ZAH dosage and initial dye concentration on dye removal was investigated. Adsorption isotherm and kinetic was evaluated. The capacity of ZAH to remove AB92, AR14, and DR23 was 95mg/g, 84mg/g and 75mg/g, respectively. Dye removal fitted with the Langmuir model and pseudo-second order kinetics.
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Herein, magnetic cobalt ferrite nanoparticles (CFNPs) was synthesized and its surface was modified by cationic surfactant (cetyltrimethyl ammonium bromide: CTAB) and its potential to selective removal of dye from multicomponent (ternary) system was investigated. Direct red 31 (DR31), Direct green 6 (DG6) and Direct red 23 (DR23) were used as a model dyes. The characteristics of the synthesized adsorbent (CFNPs-CTAB) nanoparticles were studied using FTIR, SEM, TEM, XRD, and TOC. Selectivity analysis showed that the magnetic adsorbent had selective removal of DR31. A reliable and intelligent model based on Least-Squares Support Vector machine (LS-SVM) was used to present pollutant adsorption efficiency. The presented model illustrates better performance in predicting dye removal efficiency compared to the kinetic models with average absolute percent relative error of 2.024% and correlation coefficients close to unity. Moreover, it was showed that the developed models are capable of simulating the actual physical trend of the dye removal efficiency with variation of adsorbent dosage, initial dye concentration, salt and initial pH of solution. The proposed model could be trustful for predicting the dye removal efficiency from colored wastewater.
In this paper, the Laccase enzyme was covalently immobilized onto nanoparticle of zeolite (NZ)-graphene oxide (GO) composites to prepare the novel nanobiocatalysts for degrading Direct Red 23 as an organic pollutant. Graphene oxide-zeolite (GZ) nanocomposites with 0.03, 0.05, and 0.07 g amounts of GO (denoted as GZ3, GZ5, and GZ7, respectively) were synthesized. The materials were silanized for synthesizing SNZ, SGZ3, SGZ5, and SGZ7. The glutaraldehyde as a cross-linking agent was used to prepare GSNZ, GSGZ3, GSGZ5, and GSGZ7. Laccase was immobilized on them for synthesizing Laccase immobilized nanobiocatalysts including LIGSNZ, LIGSGZ3, LIGSGZ5, and LIGSGZ7. The SEM, FESEM, XRD, FTIR, TEM, HPLC, and UV–vis were used for characterizing materials and dye degradation. The effects of GO ratio, catalyst dosage, dye concentration and pH on pollutant biodegradation were evaluated and optimized. The nanobiocatalysts indicated well reusability over five cycles, high storage stability, and thermal stability.
In this paper, polyaminoimide homopolymer (PAIHP) was synthesized and its dye removal ability was investigated. Physical characteristics of PAIHP were studied using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). Direct Red 31 (DR31), Direct Red 23 (DR23), Direct Black 22 (DB22) and Acid Blue 25 (AB25) were used as model compounds. The kinetic and isotherm of dye adsorption were studied. The effect of operational parameter such as adsorbent dosage, pH and salt on dye removal was evaluated. Adsorption kinetic of dyes followed pseudo-second order kinetics. The maximum dye adsorption capacity (Q 0) of PAIHP was 6667mg/g, 5555mg/g, 9090mg/g and 5882mg/g for DR31, DR23, DB22 and AB25, respectively. It was found that adsorption of DR31, DR23, DB22 and AB25 onto PAIHP followed with Langmuir isotherm. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 90% for DR31, 86% for DR23, 87% for DB22 and 90% for AB25 were achieved in aqueous solution at pH 12. The results showed that the PAIHP as a polymeric adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored wastewater.
Herein, COF (Covalent Organic Framework), MIL100 (Materials Institute Lavoisier), CuFe2O4 and COF/MIL100/CuFe2O4 hybrids were synthesized and characterized. The COF/MIL100/CuFe2O4 hybrids with different amounts of COF (0.3, 0.6, and 0.15 g) were competently synthesized through a hierarchical approach and denoted as COF/MIL100/CuFe2O4 (2:1), COF/MIL100/CuFe2O4 hybrid (1:1), and COF/MIL100/CuFe2O4 hybrid (1:2), respectively. This hybrid exhibited impressive photocatalytic capabilities for the degradation of pharmaceutical (TCN: tetracycline) and dye (MG: Malachite Green) contaminants. The MG degradation (100 mL of 20 mg/L dye solution at natural pH) using COF, MIL100, CuFe2O4, hybrid (1:1), hybrid (2:1), and hybrid (1:2) was 66 %, 43 %, 32 %, 99 %, 95 %, and 85 %, respectively. Also, the TCN removal (100 mL of solution and 5 mg of composites at natural pH) was 59 %, 61 %, 34 %, 80 %, 77 %, and 74 % using COF, MIL100, CuFe2O4, hybrid (1:1), hybrid (2:1), and hybrid (1:2), respectively. Examination of degradation kinetics demonstrated first-order behavior for tetracycline and zero-order behavior for malachite green. Active species assessment, emphasizes the substantial involvement of holes (h+), and hydroxyl ( OH) radicals in the photodegradation mechanism. Also, the hybrid provided good stability and performance even after being used for five cycles. This research presents a concept for the development of an efficient photocatalyst, leveraging the enhanced performance and magnetic separation capacity achieved through the synergistic combination of MIL100, COF, and magnetic nanoparticles (CuFe2O4).
No abstract is provided for this article.
No abstract is provided for this article.
The effect of pH on equilibrium and kinetics of dye adsorption onto canola hull as a biosorbent was studied. Reactive Red 198 (RR198), Reactive Blue 19 (RB19), Direct Red 79 (DR79), and Direct Red 80 (DR80) were used as model textile dyes. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and UV–vis spectroscopy were used. The presence of functional groups onto canola hull was investigated using FTIR spectroscopy. The pseudo first‐order, pseudo second‐order and intraparticle diffusion kinetics models were examined to evaluate the kinetics data. The Langmuir, Freundlich, and Tempkin adsorption isotherm models were applied to describe the equilibrium isotherms. The FTIR spectrum proved the presence of functional groups such as hydroxyl and amino groups in canola hull surface. The results showed that the adsorption of RR198, RB19, DR79, and DR80 onto canola hull followed Tempkin isotherm. Adsorption kinetic of dyes followed pseudo second‐order kinetics. Desorption tests showed maximum dye releasing of 88% for RR198, 86% for RB19, 91% for DR79, and 95% for DR80 at pH 12. Data showed that canola hull could be used as a novel natural material for the removal of anionic dyes from wastewater. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
