Development of chitosan-based granular adsorbents for enhanced and selective adsorption performance in heavy metal removal

2006 ◽  
Vol 54 (10) ◽  
pp. 103-113 ◽  
Author(s):  
N. Li ◽  
R. Bai
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Selective Adsorption ◽  
Cross Linking ◽  
The Novel ◽  
Chitosan Beads ◽  
Hydrogel Beads ◽  
Amine Groups ◽  
The Cross

Novel chitosan-based granular adsorbents were developed for enhanced and selective separation of heavy metal ions. The research included the synthesis of chitosan hydrogel beads, the cross-linking of the hydrogel beads with ethylene glycol diglycidyl ether (EGDE) in a conventional and a novel amine-shielded method, the functionalization of the chitosan beads through surface grafting of polyacrylamide via a surface-initiated atom transfer radical polymerization (ATRP) method, and the examination of the adsorption performance of the various types of chitosan beads in the removal of heavy metal ions. It was found that chitosan beads were effective in heavy metal adsorption, the conventional cross-linking method improved the acidic stability of the beads but reduced their adsorption capacity, the novel amine-shielded cross-linking method retained the good adsorption capacity while it improved the acidic stability of the beads, and the grafting of polyacrylamide on chitosan beads not only enhanced the adsorption capacity but also provided the beads with excellent selectivity for mercury over lead ions. XPS analyses indicated that the adsorption of metal ions on chitosan beads was mainly attributed to the amine groups of chitosan, the novel amine-shielded cross-linking method preserved most of the amine groups from being consumed by the cross-linking process and hence improved the adsorption capacity of the cross-linked chitosan beads, and the many amide groups from the polyacrylamide grafted on the chitosan beads increased the adsorption capacity and also made possible selective adsorption of mercury ions because the amide groups can form covalent bonds with mercury ions.

scholarly journals Effects of Electronegativity and Hydration Energy on the Selective Adsorption of Heavy Metal Ions by Synthetic NaX Zeolite

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4066
Author(s):  
Xianyuan Fan ◽  
Hong Liu ◽  
Emmanuella Anang ◽  
Dajun Ren
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Heavy Metal Ions ◽  
Binary Systems ◽  
Adsorption Mechanism ◽  
Selective Adsorption ◽  
Hydration Energy ◽  
Nax Zeolite ◽  
High Electronegativity

The adsorption capacity of synthetic NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ in single and multi-component systems were investigated. The effects of electronegativity and hydration energy on the selective adsorption, as well as potential selective adsorption mechanism of the NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ were also discussed. The maximum adsorption capacity order of the heavy metals in the single system was Pb2+ > Cd2+ > Cu2+ > Zn2+, and this could be related to their hydration energy and electronegativity. The values of the separation factors (α) and affinity constant (KEL) in different binary systems indicated that Pb2+ was preferentially adsorbed, and Zn2+ presented the lowest affinity for NaX zeolite. The selective adsorption capacities of the metals were in the order, Pb2+ > Cd2+ ≈ Cu2+ > Zn2+. The trend for the selective adsorption of NaX zeolite in ternary and quaternary systems was consistent with that in the binary systems. Pb2+ and Cu2+ reduced the stability of the Si-O-Al bonds and the double six-membered rings in the NaX framework, due to the high electronegativity of Pb2+ and Cu2+ than that of Al3+. The selective adsorption mechanism of NaX zeolite for the high electronegative metal ions could mainly result from the negatively charged O in the Si-O-Al structure of the NaX zeolite, hence heavy metal ions with high electronegativity display a strong affinity for the electron cloud of the oxygen atoms in the Si-O-Al. This study could evaluate the application and efficiency of zeolite in separating and recovering certain metal ions from industrial wastewater.

scholarly journals Hg selective adsorption on polypropylene-based hollow fiber grafted with polyacrylamide

2017 ◽  
Vol 36 (1-2) ◽  
pp. 287-299 ◽  
Author(s):  
Changkun Liu ◽  
Jizhen Jia ◽  
Ji’an Liu ◽  
Xiaoyan Liang
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Hollow Fiber ◽  
Heavy Metal Ions ◽  
Hollow Fiber Membrane ◽  
Selective Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Fiber Membrane

A novel polypropylene hollow fiber membrane with a new function of selective adsorption of mercury ions in aqueous solutions was successfully prepared. The surface of the polypropylene hollow fiber membrane was initially modified with polydopamine by surface polymerization, and subsequently grafted with polyacrylamide (PAM) polymer brush via the surface initiated atom transfer radical polymerization (SI-ATRP) technique (thereafter named as PP-PAM). This study investigated the adsorption performance of Hg(II) ions by PP-PAM and the effect of various influencing factors on Hg(II) ion adsorption. The experiment indicated that the Hg(II) adsorption capacity of the PP-PAM increased with the increase of the pH, and the Hg(II) adsorption kinetics was consistent with the pseudo-second-order kinetic model. The adsorption isotherm followed the Langmuir model, with the maximum adsorption capacity calculated to be 0.854 mmol/g for Hg(II) ions. The adsorption study in multi-component system indicated that PP-PAM preferentially adsorbs Hg(II) over Pb(II) ions, with significant adsorption capacity difference of the two heavy metal ions. This study provided an efficient method for the preparation of the adsorptive polypropylene hollow fiber membrane, which expands its application for the selective removal of heavy metal ions.

scholarly journals IMMOBILIZATION OF HUMIC ACID ON CHITOSAN BEADS BY PROTECTED CROSS-LINKING METHOD AND ITS APPLICATION AS SORBENT FOR Pb(II)

2010 ◽  
Vol 10 (1) ◽  
pp. 88-95
Author(s):  
Radna Nurmasari ◽  
Uripto Trisno Santoso ◽  
Dewi Umaningrum ◽  
Taufiqur Rohman
Keyword(s):  
Humic Acid ◽  
Adsorption Capacity ◽  
Active Sites ◽  
Cross Linking ◽  
Basic Solution ◽  
Chitosan Beads ◽  
Reaction Method ◽  
The Cross

Immobilization of humic acid (HA) on chitosan beads has been done using a protected cross-linking reaction method and the product was then utilized as sorbent for Pb(II). Protection of the active sites of HA was carried out by interacting HA with Pb(II) before performing the cross-linking reaction in order to maintain its adsorption capacity. Protected-HA was cross-linked with chitosan beads using glutaraldehyde in order to obtain sorbent insoluble both in aqueous acidic and basic solution. The result showed that the amount of immobilized HA on beads chitosan was 88.60% by weight. The adsorption capacity of the protected-sorbent beads for Pb(II) was 784 mg/g. As a comparison, the adsorption capacity of the non-protected sorbent beads for Pb(II) was only 142 mg/g.   Keywords: immobilization, adsorption, crosslinking, humic acid, chitosan

Preparation of Pb(II)-Imprinted-Carboxymethyl Chitosan-Pectin-BADGE Film as Sorbent for Pb(II) Ion

2015 ◽  
Vol 798 ◽  
pp. 384-389
Author(s):  
Budi Hastuti ◽  
Mudasir ◽  
Dwi Siswanta ◽  
Triyono
Keyword(s):  
Ir Spectroscopy ◽  
Bisphenol A ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Selective Adsorption ◽  
Carboxymethyl Chitosan ◽  
Wave Number ◽  
Hydroxyl Group ◽  
Cross Linking ◽  
Selective Adsorbent

Cross-linked metal-imprinted Carboxymethyl Chitosan-Pectin (CMC-Pec) were prepared from CMC and pectin, using Pb (II) ion as a template and Bisphenol A diglycidil ether (BADGE) as the cross-linking agent. The film was prepared in order to obtain a selective adsorbent for Pb (II) ion. The film was characterized using infrared (IR) spectroscopy. The result showed that the active group of the Pb (II)-imprinted CMC-Pec-BADGE film was hydroxyl group (-OH) and carboxylic (-COOH) as indicated by IR peaks at the wave number 3300-3600 cm-1and 1600-1800 cm-1, respectively. The Pb (II) adsorption capacity of the Pb (II)-imprinted CMC-Pec-BADGE film was 12.18 mg/g. The film showed a selective adsorption for Pb (II) metal ions compared to the adsorption of Zn (II) and Cu (II) in mole ratio of 1: 1: 1.

scholarly journals Novel ionic surface imprinting technology: design and application for selectively recognizing heavy metal ions

RSC Advances ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 2431-2440 ◽  
Author(s):  
Fu-Qiang An ◽  
Hu-Fei Li ◽  
Xu-Dong Guo ◽  
Bao-Jiao Gao ◽  
Tuo-Ping Hu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Chemical Stability ◽  
Heavy Metal Ions ◽  
Selectivity Coefficient ◽  
Surface Imprinting ◽  
Technology Design ◽  
Surface Imprinting Technology ◽  
Design And Application

SIPs have good chemical stability and reusability. They could be reused without a significant reduction in adsorption capacity and selectivity coefficient.

Hydrogel beads based on carboxymethyl cellulose for removal heavy metal ions

2010 ◽  
Vol 119 (2) ◽  
pp. 1204-1210 ◽  
Author(s):  
Shaoping Yang ◽  
Shiyu Fu ◽  
Hao Liu ◽  
Yiming Zhou ◽  
Xueyun Li
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Carboxymethyl Cellulose ◽  
Heavy Metal Ions ◽  
Hydrogel Beads
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