Study on the Adsorption of Mixed Cd(II) and Pb(II) Ions by N,O-Carboxymethyl-Chitosan

2011 ◽  
Vol 236-238 ◽  
pp. 2523-2528
Author(s):  
Shan Shan Cheng ◽  
Chao Hua Zhang ◽  
Xi Hong Yang ◽  
Wan Cui Xie

TheN,O-carboxymethyl-chitosan (N,O-CMC) was used to investigate the adsorptions of two metals of Cd(Ⅱ) and Pb(Ⅱ) ions in an mixed aqueous solution. The effects on adsorption capacities such as pH value, temperature, adsorbent dose and initial metal ion concentrations were investigated, and the dialysis method was applied to separate the materials after adsorption. The results revealed that the better adsorption ofN,O-CMC for Cd(Ⅱ) and Pb(Ⅱ) ions at the pH 7-8; the effect of temperature on the adsorption was not significant; the absorption of Cd(Ⅱ) and Pb(Ⅱ) ions was enhanced with the increase ofN,O-CMC amount; the adsorption capacity increasesed with the addition of the concentration of initial metal ions in the aqueous phase. The adsorption of Pb(Ⅱ) ion in Cd-Pb mixed solution on theN,O-CMC was well followed as the Langmuir isotherm equation under the concentration range studied, and Cd(Ⅱ) ion was corresponding to Langmuir adsorption equation in 100-200 mg/L and 200-500 mg/L, respectively. Conclusion:N,O-CMC was suitable for adsorbent to removal Cd(Ⅱ) and Pb(Ⅱ) ions, but it can selectively adsorption ions from the mixed solution, the adsorption capacity (Qm) for two metal ions was as follows: Pb(Ⅱ) > Cd(Ⅱ).

2020 ◽  
Vol 840 ◽  
pp. 10-15
Author(s):  
Dian Hana Saraswati ◽  
Mellia Harumi ◽  
Triyono Triyono ◽  
Sri Sudiono

Adsorption of Au(III) and Cu(II) by mangosteen rind adsorbent had been carried out. Mangosteen rind has several functional groups including –OH phenolics, ‒C=C‒ aromatics, and ethers. Dried mangosteen rind which was obtained from maceration was used to determine Point of Zero Charge (PZC). The most effective pH adsorption was determined by mixing adsorbent with Au(III) or Cu(II) solutions with various pH. The adsorption capacity was affected by the interaction between adsorbent and adsorbate. The solid adsorbent before and after interaction was characterized by FTIR, XRD, and microphotography. The PZC pH value of adsorbent was 3.7 while the optimum pH for Au(III) and Cu(II) were at pH 2 and pH 5, respectively. The adsorption capacity (qmax) value was 333.33 mg/g by following the Langmuir isotherm equation. The crystalline structure of adsorbent was analyzed using XRD and gave 4 peaks characteristics of gold metal on 2ϴ = 38º, 44º, 64º, and 77º after adsorption which indicated the reduction of Au(III) ions into Au(0).


2015 ◽  
Vol 6 (2) ◽  
pp. 310-324 ◽  
Author(s):  
Selvaraj Dinesh Kirupha ◽  
Selvaraj Kalaivani ◽  
Thangaraj Vidhyadevi ◽  
Periyaraman Premkumar ◽  
Palanithamy Baskaralingam ◽  
...  

A novel poly [2,5-(1,3,4-thiadiazole)-benzalimine] abbreviated as TDPI adsorbent was synthesized using simple polycondensation technique. The synthetic route involves the preparation of 2,5-diamino-1,3,4-thiadiazole from 2,5-dithiourea and subsequent condensation with terephthalaldehyde. The resin was chemically characterized using Fourier transform infrared (FT-IR), 1H-NMR, and 13C-NMR spectroscopic analysis. Surface morphology and thermal stability were analyzed using scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The effect of the pH value of solution, contact time, adsorbent dose, and initial metal ion concentration were investigated by batch equilibrium adsorption experiments. Kinetic studies show that the adsorption of metal ions onto the resin proceeds according to the pseudo-second-order model and the equilibrium data were best interpreted by the Redlich–Peterson isotherm. The experimental values of the adsorption capacities of Pb2+, Cu2+, Ni2+, and Cd2+ on to TDPI could reach up to 437.2, 491.6, 493.7, and 481.9 mg.g−1 respectively. The exothermic nature of the process, the affinity of the adsorbent towards the metal ions and the feasibility of the process are explained in the thermodynamic parameters. The resin stability and re-usability studies suggest that the resin is chemically stable (0.3 N HCl and H2SO4) and could be regenerated without any serious decline in performance.


2011 ◽  
Vol 239-242 ◽  
pp. 2310-2316 ◽  
Author(s):  
Chun Mei Niu ◽  
Shao Ying Li ◽  
Dong Huang

Crosslinked Carboxymethyl Konjac Glucomannan(CMKGM) with substitution degrees ofcarboxymethyl group(DS)0.265, 0.457 and 0.586 were prepared through reaction of monochloroacetic acid, konjac glucomannan(KGM) and epichlorohydrin and used to adsorb Cu(II) from the aqueous solutions of copper nitrate. The effects of pH, adsorbent dose, initial concentration of Cu(II), adsorption time and temperature on adsorption capacity were investigated. The results showed that adsorption capacity increased with an increasing DS of the carboxymethyl groups. Equilibrium adsorption time was 20 min or so and was independent on DS. The adsorption followed Langmuir isotherm equation. Ligand ion adsorption between carboxymethyl group and Cu(II) was thought to be predominate in the process of adsorption according to the relationship between DS and thermodynamic parameters. CMKGM can be used as cheaper and more effective adsorbents.


2019 ◽  
Vol 31 (3) ◽  
pp. 602-606
Author(s):  
Ch. Shanti Devi ◽  
S. Manimukta Devi ◽  
N. Shubhaschandra Singh

In this study, environmentally friendly hydrogels prepared from hydroxy propyl cellulose hydrogels blended with poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) were employed to absorb selected metal ions of Cu and Fe to find potential applications in removal of metal ion from water or in wastewater treatment. Highest adsorption capacity of hydroxy propyl cellulose hydrogels blended with PVA or PVP is shown at 0.04 % (w/v) of the metal ion solutions. Hydroxy propyl cellulose hydrogel when blended PVA has shown greater adsorption of Fe(III) ion than Cu(II) ion at higher pH. Hydroxy propyl cellulose hydrogel when blended with PVP also showed maximum adsorption capacity rather than PVA blended hydrogel.


2012 ◽  
Vol 550-553 ◽  
pp. 671-675 ◽  
Author(s):  
Shi Xiong Yi ◽  
Yong Chun Dong

Abstract: The non-ionic reverse micelles used for dyeing cotton fabric were prepared with a non-ionic surfactant Triton X-100 (TX-100) by injecting small amount of reactive dye aqueous solution. The effect of electrolyte on the adsorption capacity of reactive dyes onto cotton fabric in this system was studied. And the adsorption properties of three water-soluble anionic azo dyes including Reactive Blue 222, Reactive Red 195 and Reactive Yellow 145 onto cotton fabric in TX-100 reverse micelle were also studied and compared. The results indicated that reactive dyes showed a better adsorption property on cotton fabric in TX-100 reverse micelle without the addition of NaCl. The adsorption of the dyes onto cotton showed better agreement with Langmuir isotherm equation. Reactive Yellow 145 with lower negative charge and higher hydrophilicity exhibited the higher adsorption capacity than the other dyes. The adsorption process follows by the chemical adsorption.


2012 ◽  
Vol 550-553 ◽  
pp. 1747-1754
Author(s):  
Ya Li Peng ◽  
Fei Hu

Limit dextrinase is one of three main amylases in malted barley, which plays a significant role during the mashing stage of brewing. Due to very low content and similar properties compared to other amylases in malted barley, limit dextrinase is hard to separate effectively. Our work had been directed towards the extraction and purification of limit dextrinase from malted barley. Final products were obtained through fraction precipitation with ammonium sulfate and column chromatography, and purified limit dextrinase acquired a high purity of 31.23 times as much as that of crude extracts. The previous results were also confirmed by sodiumdodecyl sulphate poly-acrylamide gel electrophoresis (SDS-PAGE) revealing a single band of protein (~97KDa). Effect of temperature, pH value, and metal ion on hydrolysis characterization of limit dextrinase was investigated. The results indicated that the maximum activity of purified samples changed significantly compared with that of crude extracts. The activity of purified limit dextrinase could be activated by lower concentration of Mg2+、Ca2+、Mn2+ and inhibited by the action of Zn2+、Fe2+. But this influence was not so obvious for K+.


2008 ◽  
Vol 5 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Nizam M. El-Ashgar

An extraction chromatographic solid porous polysiloxane functionalized by chelating diethylenetriamine ligand of the general formula P-(CH2)3-NH(CH2)2NH(CH2)2NH2, (Where P represents [Si-O]nsiloxane network) has been evaluated for the separation of Co(II), Ni(II) and Cu(II) from aqueous solutions. The chromatographic parameters of the separation method have been optimized. The ligand system retained Co(II), Cu(II) and Zn(II) effectively when used as a metal ion extractant by controlling the pH value. The ligand system also shows a good separation of a mixture of metal ions Co(II), Ni(II) and Cu(II) when used as chromatographic stationary phase. The optimum separation pH values were 4.5, 4 for Co(II) and Ni(II) respectively, while a solution of 0.1 M HNO3was used to elute Cu(II). Metal ions were also preconcentrated at pH 5.5. The chemisorbed metal ions were regenerated from the solid extractant using 0.5 M HCl.


2013 ◽  
Vol 68 (8) ◽  
pp. 1873-1879 ◽  
Author(s):  
Chongxia Wang ◽  
Qingping Song ◽  
Jiangang Gao

N-carboxymethyl chitosan (NCMC) was prepared by reacting chitosan (CTS) with chloroacetic acid and characterized by 13C-NMR spectroscopy to confirm that carboxymethylation occurred only in the amino groups. The adsorption properties of CTS, NCMC and O-carboxymethyl chitosan (OCMC) towards Pb(II) ions were evaluated and the order of the adsorption capacity was as follows: NCMC > OCMC > CTS. The effects of initial pH value (2.0–5.5) of the solutions and contact time (5–120 min) on adsorption of Pb(II) were investigated and the kinetic data were evaluated using the pseudo-first-order and pseudo-second-order models. Kinetics study showed that the adsorption process followed second-order kinetics rather than the first-order one. Furthermore, the experimental equilibrium data of Pb(II) on the NCMC were analyzed using the Langmuir and Freundlich isotherm models and the results indicated that the Langmuir model gave a better fit than the Freundlich equation and the maximum adsorption capacity obtained from the Langmuir model was 421.9 mg g−1.


Author(s):  
Huiqing Lou ◽  
Siyu Li ◽  
Xiangwei Feng ◽  
Xianzhong Cao

Abstract Adsorptive properties for Cd(II), Cr(III), Cu(II), Ni(II), Pb(II) and Zn(II) onto an amidoxime-functionalized polyacrylonitrile (APAN) micro/nanofibers were systematically investigated in hexahydroxy metallic solution system using batch experiments. The interactive effect of multi-metal ions in multi- metal systems was antagonistic in nature, and the adsorption capacity in multi-metal system was lower than that in single-metal system. The Langmuir isotherm model could explain respectively the isotherm and kinetic experimental data for hexahydroxy metallic system with much satisfaction. The maximum adsorption capacity in hexahydroxy metallic for Cd(II), Cr(III), Cu(II), Ni(II), Pb(II) and Zn(II) was calculated to be 98 mg/L, 158 mg/L, 80 mg/L, 76, 312 and 58 mg/L individually. The APAN micro/nanofibers possessed good selectivity toward Pb(II) and Cr(III), over Cd(II), Cu(II), Ni(II), and Zn(II), having the highest selectivity coefficients at 17.52 and 6.07 in the test range. The five adsorption-desorption cycle experiments exhibited that APAN micro/nanofibers adsorbent are readily reusable, and have potential for heavy metal removal from wastewater. The adsorption behavior in multi-metal systems was shown to be complex, including surface complexation, antagonistic competition and displacement reactions. The diversity and selectivity in metal ion adsorption onto the micro/nanofibers relate mainly to the stability constants, and the microscopic coupling mechanism between the heavy metal ions and the functional groups on the fiber surface. This interaction mechanism between the favorable component and other metal ions could contribute significantly to the direct displacement impact illustrated schematically.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 286 ◽  
Author(s):  
Radhia Msaadi ◽  
Gorkem Yilmaz ◽  
Andrit Allushi ◽  
Sena Hamadi ◽  
Salah Ammar ◽  
...  

There is an urgent demand worldwide for the development of highly selective adsorbents and sensors of heavy metal ions and other organic pollutants. Within these environmental and public health frameworks, we are combining the salient features of clays and chelatant polymers to design selective metal ion adsorbents. Towards this end, the ion imprinting approach has been used to develop a novel nanohybrid material for the selective separation of Cu2+ ions in an aqueous solution. The Cu2+-imprinted polymer/montmorillonite (IIP/Mt) and non-imprinted polymer/montmorillonite (NIP/Mt) nanocomposites were prepared by a radical photopolymerization process in visible light. The ion imprinting step was indeed important as the recognition of copper ions by IIP/Mt was significantly superior to that of NIP/Mt, i.e., the reference nanocomposite synthesized in the same way but in the absence of Cu2+ ions. The adsorption process as batch study was investigated under the experimental condition affecting same parameters such as contact time, concentration of metal ions, and pH. The adsorption capacity of Cu2+ ions is maximized at pH 5. Removal of Cu2+ ion achieved equilibrium within 15 min; the results obtained were found to be fitted by the pseudo-second-order kinetics model. The equilibrium process was well described by the Langmuir isothermal model and the maximum adsorption capacity was found to be 23.6 mg/g. This is the first report on the design of imprinted polymer nanocomposites using Type II radical initiators under visible light in the presence of clay intercalated with hydrogen donor diazonium. The method is original, simple and efficient; it opens up new horizons in the general domain of clay/polymer nanocomposites.


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