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1.
Cr (VI) is a highly toxic pollutant to humans, to achieve high adsorption capacity, easy recovery, and good reusability, polyethersulfone/polydopamine (PES/PDA) ultrafine fibers were prepared successfully. A series of preparing effect factors were investigated systematically and the optimum one is 8.5 pH value at room temperature and 2 g/L dopamine concentration. And then they were used as an adsorbent for the removal of Cr (VI) ions from wastewater. The effect factors pH, the adsorbent dosage, and time were discussed on Cr (VI) adsorption process and the Cr (VI) adsorption behavior was investigated. It is found that the maximum Cr (VI) adsorption capacity is 115.2 ± 4.8 mg/g at pH = 3 using 0.06 g PES/PDA with 80 mins. The Cr (VI) adsorption process followed the pseudo-second-order model (r2 ≥ 0.99) and adsorption isotherms were fitted to the Langmuir model (R2 ≥ 0.999). Furthermore, the Cr (VI) adsorption mechanism was supposed according to the X-ray photoelectron spectroscopic results. Finally, PES/PDA ultrafine fibers were considered to be a promising adsorbent with good stability (decomposing temperature, 356°C), high adsorption efficiency (112.1 ± 2.5 mg/g), and good reusability (three times) on the coexistence of anions and the actual industry wastewater environment. 相似文献
2.
《分离科学与技术》2012,47(13):3563-3581
Abstract The adsorption of Cr(VI) from aqueous solution by Turkish vermiculite were investigated in terms of equilibrium, kinetics, and thermodynamics. Experimental parameters affecting the removal process such as pH of solution, adsorbent dosage, contact time, and temperature were studied. Equilibrium adsorption data were evaluated by Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models. Langmuir model fitted the equilibrium data better than the Freundlich model. The monolayer adsorption capacity of Turkish vermiculite for Cr(VI) was found to be 87.7 mg/g at pH 1.5, 10 g/L adsorbent dosage and 20°C. The mean free energy of adsorption (5.9 kJ/mol) obtained from the D–R isotherm indicated that the type of sorption was essentially physical. The calculated thermodynamic parameters (ΔG o , ΔH o and ΔS o ) showed that the removal of Cr(VI) ions from aqueous solution by the vermiculite was feasible, spontaneous and exothermic at 20–50°C. Equilibrium data were also tested using the adsorption kinetic models and the results showed that the adsorption processes of Cr(VI) onto Turkish vermiculite followed well pseudo-second order kinetics. 相似文献
3.
Enhanced adsorptive removal of Cr(VI) in aqueous solution by polyethyleneimine modified palygorskite
Polyethyleneimine (PEI) modified palygorskite (Pal) was used for the adsorption of Cr(VI) in aqueous solution. The absorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). Characterized results confirmed that the Pal has been successfully modified by PEI. The modification of PEI increased the Cr(VI) adsorption performance of the Pal by the adsorption combined reduction mechanism, and amino groups of the adsorbent play the main role in the enhanced Cr(VI) adsorption. The maximum adsorption capacity was 51.10 mg·g−1 at pH 4.0 and 25 °C. The adsorption kinetics of Cr(VI) on the adsorbent conforms to the Langmuir isotherm model. The maximum adsorption occurs at pH 3, and then the adsorption capacity of PEI-Pal was decreased with the increase of pH values. The adsorption kinetics of Cr(VI) on PEI-Pal was modeled with pseudo-second-order model. The addition of Cl−, SO42− and PO43− reduced the Cr(VI) adsorption by competition with Cr(VI) for the active sites of PEI-Pal. The Cr(VI) saturated PEI-Pal can be regenerated in alkaline solution, and the adsorption capacity can still be maintained at 30.44 mg·g−1 after 4 cycles. The results demonstrate that PEI-Pal can be used as a potential adsorbent of Cr(VI) in aqueous solutions. 相似文献
4.
Mridusmita Goswami Lukumoni Borah Debajyoti Mahanta Prodeep Phukan 《Journal of Porous Materials》2014,21(6):1025-1034
A new porous carbon with high surface area of 1,313.41 m2 g?1 with pore volume 1.359 cm3 g?1 has been synthesized from matured tea leaves by chemical activation method using phosphoric acid. The carbon was found to be highly efficient for removal of Cr(VI) from aqueous solution. The effects of various parameters such as contact time, initial metal ion concentration, pH, temperature and amount of adsorbent on the extent of adsorption were studied. Langmuir, Freundlich and Temkin adsorption models were used to interpret the experimental data. The adsorption data were best fitted with Langmuir isotherm model. The adsorption capacity of Cr(VI) onto the activated carbon calculated from Langmuir isotherm was found to be 30.8 mg g?1 at pH 4.8 and temperature 303 K. The adsorption capacity increases from 25.36 to 32.04 mg g?1 with an increase in temperature from 303 to 323 K at initial Cr(VI) concentration of 60 mg L?1. The adsorption process followed a pseudo second order kinetic model. Thermodynamic parameters ΔH0 (28.6 KJ mol?1), ΔG0 at three different temperatures [(?0.145, ?1.09, ?2.04) KJ mol?1] and ΔS0 (94.87 J mol?1 K?1) were calculated. These values confirm the adsorption process to be endothermic and spontaneous in nature. 相似文献
5.
Sorption of hexavalent chromium ions from aqueous solution by poly 4‐vinyl pyridine [Poly(4‐VP)] was studied. The batch method was applied for adsorption processes. The effects of initial ion concentration, time, pH and temperature on adsorption were investigated. A treatment time of 60 min was found to be sufficient to reach equilibrium. pH 3.0 was found as the optimum pH value for the process. The maximum adsorption performance was achieved at 86.7 mg g?1 using 500 mg L?1 Cr (VI) solutions. The process of adsorption of Cr (VI) was explained by Langmuir isotherm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2865–2870, 2006 相似文献
6.
《Separation and Purification Technology》2002,26(2-3):137-146
Modified activated carbon are carbonaceous adsorbents which have tetrabutyl ammonium iodide (TBAI) and sodium diethyl dithiocarbamate (SDDC) immobilised at their surface. This study investigates the adsorption of toxic ions, copper, zinc, chromium and cyanide on these adsorbents that have undergone surface modification with tetrabutyl ammonium (TBA) and SDDC in wastewater applications. The modification technique enhance the removal capacity of carbon and therefore decreases cost-effective removal of Cu(II), Zn(II), Cr(VI) and CN− from metal finishing (electroplating unit) wastewater. Two separate fixed bed modified activated carbon columns were used; TBA-carbon column for cyanide removal and SDDC-carbon column for multi-species metal ions (Cu, Zn, Cr) removal. Wastewater from electroplating unit containing 37 mg l−1 Cu, 27 mg l−1 Zn, 9.5 mg l−1 Cr and 40 mg l−1 CN− was treated through the modified columns. A total CN− removal was achieved when using the TBA-carbon column with a removal capacity of 29.2 mg g−1 carbon. The TBA-carbon adsorbent was found to have an effective removal capacity of approximately five times that of plain carbon. Using SDDC-carbon column, Cu, Zn and Cr metal ions were eliminated with a removal capacity of 38, 9.9 and 6.84 mg g−1, respectively. The SDDC-carbon column has an effective removal capacity for Cu (four times), Zn (four times) and Cr (two times) greater than plain carbon. 相似文献
7.
Modified chitosan beads (CB) were prepared and used for the removal of Fe(III) ions from aqueous solution. The advantages of modified CB than raw CB have been explored. The sorption capacity (SC) of the modified forms of CB namely, protonated CB, carboxylated CB, and grafted CB were found to be 3533, 3905, and 4203 mg kg?1, respectively, while the raw CB showed the SC of 2913 mg kg?1 only. Batch adsorption studies were conducted to optimize various equilibrating conditions like contact time, pH, and coions. The sorbents were characterized by FTIR, WDXRF, and SEM with EDAX analysis. The sorption process has been explained with Freundlich and Langmuir isotherms. Thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were calculated to understand the nature of sorption. Modified CB are more selective for Fe(III) than Cu(II), which inturn higher than Cr(VI). A suitable mechanism for iron sorption onto modified CB was established. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
8.
Mithun K. Debnath Mohammad A. Rahman Hideto Minami Mohammad M. Rahman Mohammad A. Alam Mohammad K. Sharafat Mohammad K. Hossain Hasan Ahmad 《应用聚合物科学杂志》2019,136(19):47524
This article describes a single-step reproducible approach for the surface modification of micrometer-sized polystyrene (PS) core particles to prepare electromagnetic PS/polyaniline–Fe3O4 (PS/PANi–Fe3O4) composite particles. The electromagnetic PANi–Fe3O4 shell was formed by simultaneous seeded chemical oxidative polymerization of aniline and precipitation of Fe3O4 nanoparticles. The weight ratio of PS to aniline was optimized to produce core–shell structure. PS/PANi–Fe3O4 composite particles were used as adsorbent for the removal of Cr(VI) via anion-exchange mechanism. The composite particles possessed enough magnetic property for magnetic separation. The adsorption was highly pH dependent. Adsorption efficiency reached 100% at pH 2 in 120 min when 0.05 g of composite particles was mixed with 30 mL 5 mg L−1 Cr(VI) solution. The adsorption isotherm fitted best with Freundlich model and maximum adsorption capacity approached 20.289 mg g−1 at 323 K. The prepared composite was found to be an useful adsorbent for the removal of soluble Cr(VI) ions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47524. 相似文献
9.
《Journal of Industrial and Engineering Chemistry》2014,20(2):480-486
Series of resin selection experiments were carried out and the KIP210 strong base anion exchange resin was confirmed to have the maximum equilibrium adsorption capacity to remove Cr(VI) from wastewater. The adsorption thermodynamics and kinetics of Cr(VI) on KIP210 resin were investigated completely and systematically. The static experiments were performed to study the effects of various parameters, such as shaking speed, resin dosage and pH during the adsorption process. The results indicate that the effect of external diffusion is eliminated at 160 rpm, the best pH value is 3.0 and the removal percentage of Cr(VI) increases with the increase of the resin dosage. The adsorption of Cr(VI) on KIP210 agrees well with the Langmuir isotherm and the adsorption parameters of thermodynamics are ΔH = 26.5 kJ mol−1, ΔS = 126.7 J mol−1 K−1 and ΔG < 0. It demonstrates that the adsorption of Cr(VI) on KIP210 is a spontaneously endothermic physisorption process. Moreover, the adsorption process can be described well by a pseudo-second-order kinetic model and the activation energy is 30.9 kJ mol−1. The kinetic analysis showed that the adsorption rate is controlled by intraparticle diffusion. The resin is successfully regenerated using the NaOH solutions. 相似文献
10.
Zahra Ghasemi Iman Sourinejad Hossein Kazemian Mojtaba Hadavifar Sohrab Rohani Habibollah Younesi 《Chemical Engineering Communications》2020,207(6):808-825
AbstractThe Na-P1 zeolite was produced from coal fly ash and modified with different environmental friendly surfactants. The potential of these green modified zeolites was investigated as adsorbents for Cr(VI) ions in a batch system. XRD, SEM, XRF, and ICP-AES analyses were used for the characterization of raw materials and zeolite samples. The environmental friendly modified zeolites successfully immobilized different toxic elements in their framework inhibiting the transfer of these toxic elements to the surrounding liquid phase. The effects of various operational parameters on Cr(VI) removal were studied. The Hexamethylenediamine (HDTMA) and Ammonyx KP (KP) modified zeolites had larger chromium removal potential than the other samples at all temperatures. The effectiveness of Cr(VI) ions elimination became greater as the pH decreased and the adsorbent dose increased. The Freundlich, Langmuir, and Dubinin–Radushkevich isotherms were fitted to the equilibrium data. The Dubinin–Radushkevich and Langmuir models gave a better fitness to equilibrium data of HDTMA-Na-P1 and KP-Na-P1, respectively. The positive and high ΔH° values showed the endothermic nature of the total Cr(VI) sorption procedure and indicated that Cr(VI) adsorption onto HDTMA-Na-P1 and KP-Na-P1 is a chemisorption. The negative ΔS° values also showed that chromium ions were stable on the surface of adsorbents. The adsorption potential of the developed eco-friendly KP-Na-P1 was higher than those of other adsorbents reported in the literature. 相似文献
11.
《分离科学与技术》2012,47(4):486-496
The efficacy of treated Shorea dasyphylla bark for Cu(II) and Cr(VI) adsorption was assessed in a batch adsorption system as a function of pH, agitation period, and initial metal concentration. The equilibrium nature of Cu(II) and Cr(VI) adsorption was described by the Freundlich, Langmuir, and Dubinin-Radushkevich isotherms. The maximum monolayer capacities of treated Shorea dasyphylla bark, estimated from the Langmuir equation were 184.66 and 42.72 mg/g for Cu(II) and Cr(VI), respectively. The experimental results were fitted using pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models; the pseudo-second order showed the best conformity to the kinetic data. Thermodynamic parameters such as enthalpy change (ΔH°), free energy change (ΔG°) and entropy change (ΔS°) were determined by applying the Van't Hoff equation. The adsorption of Cu(II) and Cr(VI) onto treated Shorea dasyphylla bark was found to be spontaneous and exothermic. The adsorption mechanism was confirmed by means of Fourier transform infrared (FTIR) and Energy dispersive X-ray (EDX) spectroscopy. The dimensionless constant separation factor (R L), indicated that treated Shorea dasyphylla bark was favorable for Cu(II) and Cr(VI) adsorption. 相似文献
12.
This study aims to remove ionic Cr(IV) from aqueous solution using Stipa tenacissima L as a biomass source. The Arabic name for the plant Stipa tenacissima L is HALFA (ALFA) ; it belongs to the category of biosorbents agro-industrial origin. Stipa tenacissima L is from the center of the province of Djelfa Algeria. This biomass was characterized by various analytical techniques such as scanning electron microscopy, energy dispersive spectroscopy and Fourier-transform infrared spectroscopy. In order to optimize the operating conditions for the determination of ions of Cr(VI), the initial concentration of Cr(VI) ions, temperature, pH of the solution and the solid/liquid ratio were individually studied. According to the results, a fix rate of about 90% was recorded. Optimum biosorption conditions were found to be pH ~1, Co = 50 mg/L, R = 5 g/L and T = 296 K. It was found that biosorption of Cr(VI) ions onto biomass of Stipa tenacissima L was better suitable to Langmuir model. The correlation coefficients for the second-order kinetic model obtained were found to be 0.996 for all concentrations. These indicate that the biosorption system studied belongs to the second-order kinetic model. Thermodynamics parameters as enthalpy, entropy of system and free energy were evaluated, which confirms the feasibility of the process. An empirical modeling was performed by using a 24 full factorial design, and the regression equation for adsorption chromium (VI) was determined from the data. The initial metal ion concentration has the most positive pronounced effect in increasing the chromium (VI) adsorption, whereas the pH and adsorbent dosage have the most negative effect on the process. 相似文献
13.
Zhengwei Luo Yiyang Xu Haonan Chen Hui Jiang Wenhua Geng Wuji Wei Zhouyang Lian 《应用聚合物科学杂志》2020,137(43):49317
Polypropylene (PP) fibers were grafted with glycidyl methacrylate (GMA) using plasma polymerization and then aminated, imprinted, and crosslinked to prepare Cr(VI)-imprinted fibers. The plasma polymerization conditions were optimized by single factor experiment and response surface methodology, and various properties and adsorption mechanism of the fibers were analyzed. The results showed that at pH 3, the imprinted fibers had a maximum Cr(VI) adsorption capacity of 173.36 mg/g, and the adsorption equilibrium could be reached within 40 min. In the presence of competing ions (SO42−, NO3− and PO43−) each at a concentration of 5 times of that of Cr(VI), the Cr(VI) adsorption rate of the fibers could be maintained at around 50%, which indicates that the imprinted fibers have high selectivity towards Cr(VI). The results also showed that the imprinted fibers had good reusability and enrichment ability, thus can be a good candidate for treating actual Cr(VI)-contaminated water. 相似文献
14.
Yung‐Pin Tsai Ruey‐an Doong Jhih‐Ci Yang Ying‐Jie Wu 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2011,86(7):949-956
BACKGROUND: This study compared the removal of aqueous Cr(VI) by multi‐walled carbon nanotubes (CNTs) modified by sulfuric acid, titanium dioxide (TiO2) and composite of CNTs and TiO2. RESULTS: More than 360 h contact time was needed to completely adsorb 3 mg L?1 of Cr(VI) by CNTs, indicating that the rate of adsorption by CNTs alone was slow. The reaction time approaching equilibrium depended on the Cr(VI) concentration. XPS analysis of CNTs after adsorbing Cr(VI) showed that the Cr(VI) on the surface of CNTs was partially reduced to Cr(III). A 3 mg L?1 solution of Cr(VI) was fully photocatalyzed by commercial TiO2 (Degussa P25) in less than 0.5 h under UV irradiation. Unlike P25, reduction by another commercial TiO2 (Hombikat UV100) took 4 h and more than 2 h were necessary for reduction by the composite. Thus the efficiency of Cr(VI) photo‐reduction by the composite was lower than by TiO2, but higher than that by CNTs. XPS analysis of TiO2 and composite showed the existence of both Cr(VI) and Cr(III) on their surfaces. CONCLUSION: In contrast to TiO2, the reduction rate of aqueous Cr(VI) using CNTs as adsorbent was slow. P25 had a markedly higher photocatalytic efficiency than the composite or UV100 alone. Using P25 to reduce aqueous Cr(VI) has a higher potential for practical application. The diameters of TiO2 and CNTs and the ratio of TiO2/CNTs are key problems in the preparation of TiO2/CNTs composite. Copyright © 2011 Society of Chemical Industry 相似文献
15.
In this work, spruce bark was used as a raw material to remove Cr(VI) ions from aqueous solutions. Three kinds of chemically modified bark adsorbents were prepared by treatment with formaldehyde (FB), dilute sulfuric acid (AB), and concentrated sulfuric acid (CB), respectively. The chemical modifications mainly changed the relative lignin content in the bark. Lower pH facilitated the adsorption of Cr(VI) ions because reduction of Cr(VI) ions to Cr(III) ions occurred during the adsorption process which consumed a large amount of H+ ions. Higher temperature accelerated the adsorption process, owing to the endothermic nature of the redox reaction. At initial solution pH around 1, the adsorption capacities of Cr(VI) ions on FB, AB, and CB were as high as 423, 503, and 759 mg/g, respectively, which were much higher than the reported adsorption capacities by other agricultural and forest biosorbents in the literatures. XPS analysis revealed the adsorption mechanism was adsorption-coupled reduction involving the electron-donor groups of lignin moieties. 相似文献
16.
S. Bhuvaneshwari 《Chemical Engineering Communications》2013,200(6):834-854
Wastewater containing low levels of pollutants can be effectively treated by the adsorption technique. In the present work, an adsorption study was carried out using chitosan as adsorbent in a fixed-bed column for the removal of Cr(VI) from wastewater solutions. The column performance of Cr(VI) adsorption onto chitosan was studied at different bed heights (3–9 cm), flow rates (50–200 mL/min), initial metal concentrations (2–10 mg/L), pH values (2–7), and temperatures (30°–60°C). The equilibrium data for the batch adsorption of Cr(VI) on chitosan were tested using the Langmuir, Freundlich, and BET isotherm models. The Langmuir model was found to be the most suitable, with a maximum adsorption capacity of 35.7 mg/g and a correlation coefficient (R 2) = 0.952. The experimental data were found to fit well with the pseudo-second-order kinetic model, with R 2 = 0.999. The dynamics of the adsorption process was modeled using the Adams-Bohart, Thomas, and mass transfer models. The models were used to predict the breakthrough curves of adsorption systems and to determine the characteristic design parameters of the column. The adsorption data were observed to fit well with all three models. The model parameters were derived using MATLAB software. In order to compare quantitatively the applicability of adsorption dynamic models in fitting to experimental data, the percentage relative deviation (P) was calculated and found to be less than 5, confirming that the fit is good for all three models. 相似文献
17.
Hexavalent chromium (Cr(VI)) adsorption from aqueous solutions on magnetically modified multi-wall carbon nanotubes (M-MWCNT) and activated carbon (M-AC) was investigated. M-MWCNT and M-AC were prepared by co-precipitation method with Fe2+:Fe3+ salts as precursors. The magnetic adsorbents were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The effects of amount of adsorbents, contact time, initial pH, temperature and the initial concentration of Cr(VI) solution were determined. The adsorption equilibrium, kinetics, thermodynamics and desorption of Cr(VI) were investigated. Equilibrium data fitted well with the Langmuir isotherm for both of the adsorbents. The theoretical adsorption capacities are 14.28 mg/g of M-MWCNT and 2.84 mg/g of M-AC. Cr(VI) adsorption kinetics was modeled with pseudo-second order model, intra-particle diffusion model and Bangham model. Thermodynamic parameters were calculated and ΔG°, ΔH° and ΔS° indicate that the adsorption of Cr(VI) onto M-MWCNT and M-AC was exothermic and spontaneous in nature. Results revealed that M-MWCNT is an easily separated effective adsorbent for Cr(VI) adsorption from aqueous solution. 相似文献
18.
《分离科学与技术》2012,47(18):2983-2992
ABSTRACTThis communication provides the eliminating of heavy metals from water resources using Ag-Mg/TiO2 nanoparticles. The nanoparticles with a size of 15 nm were prepared using sol-gel technique and used for the removal of Cr(VI) and Cu(II) from waste waters. Batch sorption studies were carried out to investigate the adsorption of the above metal ions for a concentration range of 0.1–10 mg/L. The maximum sorption capacity values were found to be 2.42 mg/g for Cr(VI) and 2.03 mg/g for Cu(II) at a concentration of 0.1 ppm. The mechanism of adsorption was also investigated. The results showed that both Freundlich and Dubinin–Radushkevitch isotherms were found to be the best fit for the adsorption of metals. The results from kinetic data reveal that the pseudo-second-order and Reichenberg film diffusion models were found to be well fit for the experimental data. The value of the thermodynamic parameter ΔH° revealed the endothermic adsorption process and negative value of ΔG° shows the feasibility and spontaneity of material–anion interaction. In addition, the method is considered to be simple and cost-effective, and shows excellent adsorption removal properties on heavy metals for industrial applications. 相似文献
19.
De-oiled spent bleaching clay was activated either by acid treatment followed by heat activation or by heat activation alone
at temperatures between 200 and 800°C. The surface area of the heat-activated clay attained a maximal value of ≈120 m2 g−1 at temperatures between 400 and 500°C while the acid-heat-treated clay attained maximal surface area of ≈140 m2 g−1. The adsorption capacities of chromium [Cr(VI)] for both series studied increased as the activation temperature increased
until 300°C and decreased again at higher temperatures. At lower pH, more than 95% of the Cr(VI) was absorbed in a solution
with initial concentration of 1 mg L−1 per gram of adsorbent activated at 300°C. The adsorption patterns followed Freudlich's isotherms. Two maximal values of adsorption
capacities of nickel [Ni(II)] were observed at activation temperatures of 200 and 500°C for acid-treated samples, whereas
these were at 200 and 700°C for the nonacid-treated samples. The amount of Ni(II) adsorbed increased with the pH of the solution
for all samples studied. The maximal adsorption capacities of the adsorbents in solution containing initial Ni(II) concentration
of 5 mg L−1 per 0.5 g of adsorbent and at pH 6 were found to be 44 and 42%, respectively, for the acid-treated sample activated at 500°C
and for the nonacid-treated sample activated at 700°C. They all obeyed both the Langmuir's and Freundlich's isotherms. 相似文献
20.
Removal of hexavalent chromium in wastewater by polyacrylamide modified iron oxide nanoparticle
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Iron oxide nanoparticle has been successfully modified by polyacrylamide and the polyacrylamide modified magnetic nanoparticles (PMMNs) were applied to remove Cr(VI) in wastewater. The vibrating sample magnetometer (VSM) spectra indicated the large saturation magnetization and superparamagnetic property of the PMMNs. This made the polyacrylamide modified iron oxide easily separate with liquid phase. Scanning electron microscope (SEM) results showed that both the synthesized iron oxide and the PMMNs were nanoscale. Batch adsorption studies had been carried out to determine the effect of pH, contact time, Cr(VI) initial concentration, and coexisting salts on the adsorption of Cr(VI). Maximum removal (98.30%) was observed from an initial concentration of 100 mg L?1 Cr(VI) at pH 3.0, 30°C. This process followed pseudo‐second‐order kinetics model and the equilibrium time was 40 min. The experimental data fitted the Langmuir isotherm better than Freundlich. Maximum adsorption amount of Cr(VI) by PMMN was 35.186 mg g?1. The effect of coexisting salts on Cr(VI) removal was not apparent even the concentration of salt was 10 times as big as the low concentration, 0.01M. It had been proposed that the mechanism of Cr(VI) uptake onto PMMN was adsorption‐coupled reduction. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40945. 相似文献