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1.
《分离科学与技术》2012,47(16):4000-4022
Abstract

The biosorption of Cu(II) and Zn(II) using dried untreated and pretreated Citrus reticulata waste biomass were evaluated. The Cu(II) and Zn(II) sorption were found to be dependent on the solution pH, the biosorbent dose, the biosorbent particle size, the shaking speed, the temperature, the initial metal ions (800 mg/L), and the contact time. Twenty-eight physical and chemical pretreatments of Citrus reticulata waste biomass were evaluated for the sorption of Cu(II) and Zn(II) from aqueous solutions. The results indicated that biomass pretreated with sulphuric acid and EDTA had maximum Cu(II) and Zn(II) uptake capacity of 87.14 mg/g and 86.4 mg/g respectively. Moreover, the Langmuir isotherm model fitted well than the Freundlich model with R 2 > 0.95 for both metal ions. The sorption of Cu(II) and Zn(II) occurred rapidly in the first 120 min and the equilibrium was reached in 240 min. FTIR and SEM studies were also carried out to investigate functional groups present in the biomass and the surface morphological changes of biomass.  相似文献   

2.
Poly[5,5??-methylene-bis(2-hydroxybenzaldehyde)1,2-phenylenediimine] resin was prepared and characterized by employing elemental, thermal analysis, FTIR, and UV?Cvisible spectroscopy. The metal uptake behavior of synthesized polymer towards Cu(II), Co(II), Ni(II), Fe(III) and Cd(II) ions was investigated and optimized with respect to pH, shaking speed, and equilibration time. The sorption data of all these metal ions followed Langmuir, Freundlich, and Dubinin?CRadushkevich isotherms. The Freundlich parameters were computed 1/n?=?0.31?±?0.02, 0.3091?±?0.02, 0.3201?±?0.05, 0.368?±?0.04, and 0.23?±?0.01, A?=?3.4?±?0.03, 4.31?±?0.02, 4.683?±?0.01, 5.43?±?0.03, and 2.8?±?0.05?mmol?g?1 for Cu(II), Co(II), Ni(II), Fe(III), and Cd(II) ions, respectively. The variation of sorption with temperature gives thermodynamic quantity (??H) in the range of 36.72?C53.21?kJ/mol. Using kinetic equations (Morris?CWeber and Lagergren equations), values of intraparticle transport and the first-order rate constant was computed for all the five metals ions. The sorption procedure is utilized to preconcentrate these ions prior to their determination by atomic absorption spectrometer. It was found that the adsorption capacity values for metal-ion intake followed the following order: Cd(II)?>?Co(II)?>?Fe(III)?>?Ni(II)?>?Cu(II).  相似文献   

3.
ABSTRACT

Hydrous titanium dioxide was impregnated on the surface of zeolite to obtain a kind of hydrous TiO2/zeolite (HTiO2/ZFA) adsorbent using the hydrothermal method. HTiO2/ZFA was characterised by scanning electron microscopy combined with energy-dispersive spectrometer, X-ray diffraction, Fourier transform infrared, particle size distribution; and the pH of zero point charge measurement and its performance for Cu(II) adsorption were investigated. It was shown that Ti was not inserted into the skeleton of ZFA and hydrous TiO2 loaded on the surface was amorphous. The pHzpc of HTiO2/ZFA decreased to pH 5.5 from pH 6.5 of ZFA. Cu(II) adsorption was favoured in a pH range of 3.0–6.0, and 90% copper could be removed in first 30?min for 60?mg?L–1 Cu(II) solution. The Langmuir isotherm model could well describe the adsorption isotherm data and the maximal Cu(II) adsorption capacity reached 251.9?mg?g–1. Moreover, the HTiO2/ZFA could be desorbed by HCl solution for further use, which implied an effective application in wastewater treatment.  相似文献   

4.
Chloromethylated polystyrene‐divinylbenzene has been functionalized with dithiooxamide. The resulting chelating resin (DTOA) has been characterized by elemental analyses, infrared spectroscopy, thermogravimetric analysis, and metal ion sorption capacities. It has been used for the preconcentration and separation of Cu(II), Zn(II), Cd(II), and Pb(II) prior to their determination by FAAS. Parameters such as the amount of the resin, effect of pH, equilibration rate, sorption and desorption of metal ions, and effect of diverse ions have been studied. The maximum sorption capacities found are 0.97, 0.12, 0.08, and 0.12 mmol g?1 for Cu(II), Zn(II), Cd(II), and Pb(II) at pH 6.0, 5.5, 1.0, and 5.5, respectively. The preconcentration factors are 100, 100, 50, and 50 for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. Recoveries of the metal ions were 96 ± 5, 97 ± 6, 96 ± 5, and 96 ± 5 at 95% confidence level, whereas the limits of detection are 2.0, 1.3, 2.5, and 25.0 μg L?1 for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. The calibration curves were linear up to 12 μg mL?1 (R2 = 1.000), 2 μg mL?1 (R2 = 0.998), 2 μg ml?1 (R2 = 1.000), and 5 μg mL?1 (R2 = 0.979) for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. The reliability of the method has been tested by analyzing certified samples. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2281–2285, 2007  相似文献   

5.
《分离科学与技术》2012,47(4):923-943
Abstract

The sorption behavior of 2.7×10?5 M solution of Th(IV) ions on 1‐(2‐pyridylazo)‐2‐naphthol (PAN) loaded polyurethane foam (PUF) has been investigated. The quantitative sorption was occurred from pH 6 to 9 from acetate buffer solutions. The sorption conditions were optimized with respect to pH, shaking time, and weight of sorbent. The sorption data followed the Freundlich, Langmuir, and Dubinin‐Radushkevich (D‐R) isotherms very successfully at low metal ions concentration. The Freundlich isotherm constant (1/n) is estimated to be 0.22±0.01, and reflects the surface heterogeneity of the sorbent. The Langmuir isotherm gives the maximum monolayer coverage is to be 8.61×10?6 mol g?1. The sorption free energy of the D‐R isotherm was 17.85±0.33 kJ mol?1, suggesting chemisorption involving chemical bonding was responsible for the adsorption process. The numerical values of thermodynamic parameters such as enthalpy (ΔH), entropy (ΔS), and Gibbs free energy (ΔG) indicate that sorption is endothermic, entropy driven, and spontaneous in nature. The adsorption free energy (ΔGads) and effective free energy (ΔGeff) are also evaluated and discussed. The effect of different anions on the sorption of Th(IV) ions onto PAN loaded PUF was studied. The possible sorption mechanism on the basis of experimental finding was discussed. A new separation procedure of Th(IV) from synthetic rare earth mixture using batch, column chromatography, and squeezing techniques were reported.  相似文献   

6.
ABSTRACT

A non-hazardous groundwater treatment waste (GWTW) was examined as a low-cost sorbent for Pb(II) and Cu(II) ions. The content of the dominant elements in GWTW was as follows: 78% Fe2O3, 7.4% P2O5, 7.4% CaO and 5.2% SiO2. The removal of Pb(II) and Cu(II) was fast, and more than 67–95% of ions were accumulated by GWTW during the first 3 min. The sorption capacity of GWTW depends on solution pH, concentration and temperature. Equilibrium data fitted well with Langmuir–Freundlich and Langmuir-partition models. The inherently formed nano-adsorbent could be utilized for the treatment of water contaminated with Pb(II) and Cu(II) ions.  相似文献   

7.
The biosorptive uranium(VI) uptake capacity of live and lyophilized Pseudomonas cells was characterized in terms of equilibrium metal loading, effect of solution pH and possible interference by selected co‐ions. Uranium binding by the test biomass was rapid, achieving >90% sorption efficiency within 10 min of contact and the equilibrium was attained after 1 h. pH‐dependent uranium sorption was observed for both biomass types with the maximum being at pH 5.0. Metal uptake by live cells was not affected by culture age and the presence of an energy source or metabolic inhibitor. Sorption isotherm studies at a solution pH of either 3.5 or 5.0 indicated efficient and exceptionally high uranium loading by the test biomass, particularly at the higher pH level. At equilibrium, the lyophilized Pseudomonas exhibited a metal loading of 541 ± 34.21 mg g?1 compared with a lower value by the live organisms (410 ± 25.93 mg g?1). Experimental sorption data showing conformity to both Freundlich and Langmuir isotherm models indicate monolayered uranium binding by the test biomass. In bimetallic combinations a significant interference in uranium loading was offered by cations such as thorium(IV), iron(II and III), aluminium(III) and copper(II), while the anions tested, except carbonate, were ineffective. Uranium sorption studies in the presence of a range of Fe3+ and SO42? concentrations indicate a strong inhibition (80%) by the former at an equimolar ratio while more than 70% adsorption efficiency was retained even at a high sulfate level (30 000 mg dm?3). Overall data indicate the suitability of the Pseudomonas sp biomass in developing a biosorbent for uranium removal from aqueous waste streams. © 2001 Society of Chemical Industry  相似文献   

8.
《分离科学与技术》2012,47(8):669-687
Abstract

The compatibility of the adsorbing colloid flotation of Cu(II) with Fe(OH)3 and sodium lauryl sulfate with a variety of precipitation pretreatment techniques was studied. Procedures were developed which permitted precipitation pretreatment and effective foam flotation polishing. The interferences of glycerol, ClO4 ?, NO3 ?, C1?, CN?, CNS?, F?, SO44 2?, HPO4 2?, HAsO4 2?, C2O4 2?, (PO3)6 6?, and EDTA with the precipitate flotation of ferric hydroxide by sodium lauryl sulfate were studied. The simultaneous adsorbing colloid flotation of Cu(II), Pb(II), and Zn(II) with Fe(OH)3 and sodium lauryl sulfate was found to be effective in the pH range 6 to 7 at ionic strengths below 0.1 mole/l. A model was analyzed for calculating surface potentials for floe surfaces having the charge distributed at discrete sites in the presence of electrolytes. Plots of surface potential versus adsorbable ion concentration were calculated for various values of the model parameters.  相似文献   

9.
Nickel was coated on carbon and it was characterized by SEM and XRD. Sorption of Cd(II) ions onto carbon and nickel‐coated carbon (Ni/C), effect of acids, pH, shaking time, loading capacity, and adsorbent weight has been investigated. Acids reduce sorption and maximum sorption takes place from deionized water and Rd values for carbon and Ni/C in deionized water are 212.9 ± 0.9 and 232.5 ± 2.5. The sorption data followed the Freundlich, Dubinin–Radushkevich (D–R), isotherms and different parameters have been calculated. Sorption free energy values have been calculated and are 12.56 ± 0.19 and 14.84 ± 0.196 for carbon and Ni/C and indicate that adsorption process is chemisorption. Increase in adsorption shows the increase in catalytic activity of the adsorbent. The variation of sorption with temperature has been used to calculate the values of ΔH, ΔS, and ΔG for Cd(II) sorption. These values show that adsorption of Cd(II) ions on the adsorbents is endothermic, spontaneous, and entropy driven. Coating of carbon with nickel has improved its adsorption properties. Adsorption behaviour provides useful information for the catalytic activity of catalysts.  相似文献   

10.
《分离科学与技术》2012,47(15):3429-3446
Abstract

2,3‐Dihydroxypyridine (DHP) was loaded onto Amberlite XAD‐16 via azo linker and the resulting resin AXAD‐16‐DHP explored for enrichment of Zn(II), Mn(II), Ni(II), Pb(II), Cd(II), Cu(II), Fe(III), and Co(II) in the pH range 4.0–6.5. The sorption capacity was found in the range 120–512 µmol g?1 and the preconcentration factor from 200 to 300. Tolerance limits for foreign species are reported. The kinetics of sorption is fast, as t1/2 is generally ≤2 min. The chelating resin can be reused for fifty cycles of sorption‐desorption without any significant change (≤2.0%) in its sorption capacity. The limit of detection values (blank + 3s) are 2.90, 3.80, 5.17, 7.02, 1.91, 1.63, 4.59, and 5.02 µg L?1 for Zn, Mn, Ni, Pb, Cd, Cu, Fe, and Co respectively. The corresponding limit of quantification (blank + 10 s) values are 5.30, 6.20, 8.38, 9.54, 4.22, 4.17, 8.62, and 9.86 µg L?1, respectively. The enrichment on AXAD‐16‐DHP coupled with monitoring by flame atomic absorption spectrometry (FAAS) is used to determine these metal ions in river and synthetic water samples, Co in vitamin tablets, and Zn in milk samples. AXAD‐16‐DHP has been found to perform better than DHP loaded cellulose and Amberlite XAD‐2.  相似文献   

11.
《分离科学与技术》2012,47(5):1017-1035
Abstract

The distribution of five metal ions (M m+) including Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) between dilute sulfate solutions and macroporous resins containing di(2-ethylhexyl) phosphoric acid (D2EHPA, HR) was investigated. Experiments were carried out as a function of aqueous pH, D2EHPA concentration in the resin phase, and temperature. The equilibrium data were numerically analyzed. It was shown that the sorption reaction could be described by assuming the formation of metal complexes with a general composition MR m (HR) n in the resin phase. For several systems a change of complex stoichiometry with temperature was observed and discussed. The apparent thermodynamic data for the formation of these complexes were also calculated.  相似文献   

12.
《分离科学与技术》2012,47(3):213-228
Abstract

Monolauryl phosphate has been employed for the removal of copper(II), manganese(II), and zinc(II) by foam flotation at various pH's and ionic strengths. Good removals of all three metal ions were obtained in the basic pH range and in the presence of up to 0.2 M sulfate. Coprecipitation of Zn(II) with ferric hydroxide was essential to attain good removal of Zn(II). The removal of Cu(II) was also good from solutions containing oxalate, silicate, phosphate, and metaphosphate; however, the presence of EDTA hinders the removal of Cu(II). The potential of lauryldithiocarbamate as a chelating surfactant for the removal of Cu(II) was explored at various pH's and in the presence of various anions. We conclude that lauryldithiocarbamate is a weak chelating agent, unable to compete efficiently for Cu(II) with anions such as CO3 2?, HPO4 2?, SiO3 2?, and EDTA. The relatively rapid decomposition of lauryldithiocarbamate in solution coupled with its weakness as a chelating surfactant make it unsuitable for the removal of Cu(II) by foam flotation.  相似文献   

13.
The aim of this research work is to investigate sorption characteristic of modified nano alumina (n-Al) for the removal of SO42? from aqueous solutions and wastewater. The sorption of SO42? by batch method is carried out. The optimum conditions of sorption were found to be: a sorbent dose of 0.3 g in 100 ml of SO42?, contact time of 35 min, pH = 5. In optimum condition, removal efficiency was 85.6% for the SO42?. Three equations, i.e. Morris–Weber, Lagergren and pseudo second order have been tested to track the kinetics of removal process. The Langmuir, Freundlich and D–R are subjected to sorption data to estimate sorption capacity. It can be concluded that n-Al has potential to remove SO42? ions from aqueous solutions at different concentrations. It was found that the temperature has positive effect on the process and negative ΔG values indicated thermodynamically feasible and spontaneous nature of the sorption. Positive value of ΔS reveals the increased randomness at the solid–solution interface during the fixation of the ion on the active sites of the sorbent. The effect of other anions was studied and it was found the existence of them in the solution has considerable effect on the sulphate removal.  相似文献   

14.
Studies on sorption of diammine Au(I) cationic complex from ammoniacal solutions of varying composition into pure and modified with butylamine α‐ZrP have been performed in the temperature change from 40 to 80°C. Experimental results have been discussed in terms of first order reaction kinetics. The activation energies of sorption of Au(I) into pure and modified α‐ZrP were found to be equal to 28 (± 3) and 84 (± 7) kJ?mol?1, respectively. The effects of concentrations of ammonia, ammonium sulfate and Cu(II) were also examined. The kinetic parameters of sorption of tetraammine Cu(II) complex from ammoniacal solutions into modified α‐ZrP were also determined.  相似文献   

15.
《分离科学与技术》2012,47(4):897-910
Abstract

N,N′‐bis(salicylidene)‐1,2‐phenylenediamine(salophen) modified activated carbon was prepared and used as an effective sorbent for solid phase extraction of Cu(II) ions from aqueous solutions. The salophen modified activated carbon showed a high sorption affinity for Cu(II). In this method a column mode was used for preconcentration of copper(II) in the pH range 3.5–6.5. The retained copper was eluted with 0.1 mol l?1 EDTA and determined by atomic absorption spectrometry. The calibration graph was linear over the copper concentration in the range 0.05–1.5 µg ml ?1. Five replicate determination of 0.4 µg ml?1 of copper(II) gave a mean absorbance of 0.385 with a relative standard deviation of 1.35%. The detection limit was 0.0133 µg ml?1. The interference of a large number of anions and cations has been studied and the optimized conditions developed were utilized for determination of copper in various real samples.  相似文献   

16.
《分离科学与技术》2012,47(13):2003-2015
Two chelating ion exchangers possessing bis(2-pyridylmethyl)amine functional groups also known as bispicolylamine Dowex M4195, Lewatit® MonoPlus TP 220 were used for the selective removal of Cu(II) ions from acidic streams. The resin was characterized by CHNS elementary analysis, surface area, pore size, and volume analysis. After cutting by ultramicrotome, scans using electron microscope and optical profiler were recorded. For the first time the interiors of these resins after the sorption process were shown. Their superior binding affinities for Cu(II) was confirmed even under high acidities. Various physiochemical parameters like solution pH, ion exchange dose, presence of chloride, and sulfate ions in the system were studied in order to determine sorption capacity and kinetic parameters. The most effective chelating ion exchanger proved to be Lewatit® MonoPlus TP 220. Cu(II) ions sorption was affected by the presence of sulfate ions in the system. The monolayer sorption capacity (q0) for Lewatit® MonoPlus TP 220 was found to be 50.69 mg g?1 and 86.44 mg g?1 in the presence of chloride ions. The sorption of Cu(II) ions was found to be well represented by the pseudo second-order kinetics. The optimal desorption conditions were found using 1 M H2SO4 and 1 M NH4OH.  相似文献   

17.
《分离科学与技术》2012,47(1):203-222
Abstract

The decontamination of lead ions from aqueous media has been investigated using styrene‐divinylbenzene copolymer beads (St‐DVB) as an adsorbent. Various physico‐chemical parameters such as selection of appropriate electrolyte, contact time, amount of adsorbent, concentration of adsorbate, effect of foreign ions, and temperature were optimized to simulate the best conditions which can be used to decontaminate lead from aqueous media using St‐DVB beads as an adsorbent. The atomic absorption spectrometric technique was used to determine the distribution of lead. Maximum adsorption was observed at 0.001 mol L?1 acid solutions (HNO3, HCl, H2SO4 and HClO4) using 0.2 g of adsorbent for 4.83×10?5 mol L?1 lead concentration in two minutes equilibration time. The adsorption data followed the Freundlich, Langmuir, and Dubinin‐Radushkevich (D‐R) isotherms over the lead concentration range of 1.207×10?3 to 2.413×10?2 mol L?1. The characteristic Freundlich constants i.e. 1/n=0.164±0.012 and A=2.345×10?3±4.480×10?5 mol g?1 have been computed for the sorption system. Langmuir isotherm gave a saturated capacity of 0.971±0.011 mmol g?1, which suggests monolayer coverage of the surface. The sorption mean free energy from D‐R isotherm was found to be 18.26±0.75 kJ mol?1 indicating chemisorption involving chemical bonding for the adsorption process. The uptake of lead increases with the rise in temperature. Thermodynamic parameters i.e. ΔG, ΔH, and ΔS have also been calculated for the system. The sorption process was found to be exothermic. The developed procedure was successfully applied for the removal of lead ions from real battery wastewater samples.  相似文献   

18.
Particles of two different sizes (0·105–0·295 mm and 0·84–1.00 mm diameter) of two marine algae, Sargassum fluitans and Ascophyllum nodosum, were crosslinked with formaldehyde (FA), glutaraldehyde (GA) or embedded in polyethylene imine (PEI), followed by glutaraldehyde crosslinking. They were used for equilibrium sorption uptake studies with cadmium, copper, nickel, lead and zinc. The metal uptake by larger particles (0·84–1·00 mm) was higher than that by smaller particles (0·105–0·295 mm). The order of adsorption for S. fluitans biomass particles was Pb > Cd > Cu > Ni > Zn, for A. nodosum copper and cadmium change places. Uptakes of metals range from qmax = 378 mg Pb g?1 for S. fluitans (FA, big particles), to qmax = 89 mg Zn g?1 for S. fluitans (FA, small particles) as the best sorption performance for each metal. Generally, S. fluitans is a better sorbent material for a given metal, size and modification, although there were several exceptions in which metal sorption by A. nodosum was higher. The metal uptake for different chemical modifications showed the order GA > FA > PEI. A comparison of different sorption models revealed that the Langmuir sorption model fitted the experimental data best.  相似文献   

19.
BACKGROUND: Bioaccumulation and biosorption by Pichia stipitis yeast has not yet been explored. This paper evaluates, for the first time, the use of both viable and nonviable P. stipitis yeast to eliminate Cu(II) and Cr(III) from aqueous solutions. The effect of Cu(II) and Cr(III) ions on the growth and bioaccumulation properties of adapted and nonadapted biomass is investigated as a function of initial metal concentration. Binding capacity experiments using nonviable biomass are also performed as a function of temperature. RESULTS: The addition of Cu(II) and Cr(III) had a significant negative effect on the growth of yeast. Nonadapted cells could tolerate Cu(II) and Cr(III) ions up to a concentration of 75 ppm. The growth rate of nonadapted and adapted cells decreased with the increase in Cu(II) and Cr(III) concentration. Adapted P. stipitis biomass was capable of removing Cu(II) and Cr(III) with a maximum specific uptake capacity of 15.85 and 9.10 mg g−1, respectively, at 100 ppm initial Cu(II) and Cr(III) concentration at pH 4.5. Adsorption data on nonviable cells were found to be well modeled by the Langmuir and Temkin isotherms. The maximum loading capacity of dry biomass predicted from Langmuir isotherm for Cu(II) and Cr(III) at 20 °C were 16.89 and 19.2 mg g−1, respectively, at pH 4.5. Biosorptive capacities were dependent on temperature for Cu(II) and Cr(III) solutions. CONCLUSION: Cu(II)‐ and Cr(III)‐adapted cells grow and accumulate these ions at high ratios. On the other hand, nonviable P. stipitis was found to be an effective biosorbent for Cu(II) and Cr(III) biosorption. Copyright © 2008 Society of Chemical Industry  相似文献   

20.
ABSTRACT

Combustion of fuels containing organosulfur compounds has resulted in the emission of sulfur oxides (SOx) into the atmosphere, therefore, causing serious environmental and health hazards. Herein, slightly distorted octahedral zig-zag 1D coordination polymer of copper(II) [Cu(4-mba)2(H2O)3] was synthesized by reacting copper sulfate pentahydrate with a carboxylate-containing ligand (H-4mba?=?4-methoxybenzoic acid) and employed for sulfur compound uptake. The ligand coordinates to the copper(II) atom via two pairs of deprotonated ligating atoms (carboxylate oxygens) and two water molecules. Structural characterization also reveals that interplay of O–H···O, N–H···O, C-H···O and C–H···π interactions between lattice and coordinated water and ligands significantly contribute to the crystal packing leading to the formation and strengthening of three-dimensional supramolecular assembly. The complex, [Cu(4-mba)2(H2O)3], show potential for desulfurization of fuel with an observed adsorption capacity of 9.6?mg/g at 32°C for 6?h. DFT calculations further revealed a transfer of electron sulfur-containing compounds and the complex, [Cu(4-mba)2(H2O)3], thus leading to a stronger pi–pi interaction.  相似文献   

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