scholarly journals Preparation of Chitosan/Calcium Alginate/Bentonite Composite Hydrogel and Its Heavy Metal Ions Adsorption Properties

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1891
Author(s):  
Zongkun Lin ◽  
Yuru Yang ◽  
Zizhan Liang ◽  
Lei Zeng ◽  
Aiping Zhang
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Calcium Alginate ◽  
Heavy Metal Ions ◽  
Crosslinking Agent ◽  
Composite Hydrogel ◽  
Maximum Adsorption Capacity ◽  
Competitive Sorption ◽  
Operation Process ◽  
Kinetics And Isotherms

In order to avoid the secondary pollution of the toxic residue of chemical crosslinking agent accompanied by chemical hydrogel adsorbent and enhance the adsorption performance of physical hydrogel, chitosan/calcium alginate/bentonite (CTS/CA/BT) composite physical hydrogel was constructed. The formation mechanism and structure of the composite hydrogel were determined by FTIR, XRD and SEM. Adsorption performances of the hydrogel toward Pb2+, Cu2+ and Cd2+ in water under different condition as well as multi-ion competitive sorption were investigated. The adsorption processes were described with the canonical adsorption kinetics and isotherms models. With the utilization of XPS analysis and adsorption thermodynamics analysis, it was found that the adsorptions were spontaneous physico-chemical adsorptions. The results showed that the maximum adsorption capacity of the hydrogel for Pb2+, Cu2+ and Cd2+ reached up to 434.89, 115.30 and 102.38 mg·g−1, respectively, better than those of other physical hydrogels or chitosan/bentonite composite. Moreover, the composite hydrogel improved the collectability of bentonite and showed a good reusability. The modification of bentonite and the formation of hydrogel were completed simultaneously, which greatly simplifies the operation process compared with the prior similar works. These suggest that the CTS/CA/BT composite hydrogel has promising application prospects for removal of heavy metal ions from water.

scholarly journals Fabrication of Lignin-based Magnetic Adsorbent via Thiol-ene Click Reaction for the Effective Removal of Pb(II)

2021 ◽  
Author(s):  
Xuan Zhou ◽  
Yunlong Liu ◽  
can Jin ◽  
Guomin Wu ◽  
Guifeng Liu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Click Reaction ◽  
Uv Light ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
High Adsorption ◽  
Adsorption Selectivity ◽  
Kinetics And Isotherms

Abstract The effective and selective removal of heavy metal ions from sewage is a major challenge, and of great significance to the treatment and recovery of metal waste. Herein, a novel magnetic lignin-based adsorbent L@MNP was synthesized by thiol-ene click reaction under UV light irradiation. Multiple characterization techniques containing FT-IR, XRD, elemental analysis, VSM, SEM and TEM confirmed the formed nano-morphology and structure of L@MNP. Effects of pH, contact time, initial metal concentration and temperature on the batch adsorption of Pb(II) by L@MNP were investigated. Due to the existence of sulfur and oxygen containing sites, the maximum adsorption capacity of L@MNP for Pb(II) could reach 97.38 mg/g, while the adsorption equilibrium was achieved within 30 min. Adsorption kinetics and isotherms were well described by the pseudo-second-order model and Langmuir model, respectively, suggesting a chemical and monolayer adsorption process. In addition, L@MNP showed a high adsorption selectivity (kPb = 0.903) toward Pb(II) in the presence of other co-existing metal ions. Experimental results also revealed that L@MNP displayed structural stability, easy recovery under external magnetic field, and acceptable recyclability after the fifth cycle. Considering its facile preparation, low cost and high adsorption efficiency, the developed L@MNP adsorbent demonstrated great potential in removing heavy metal ions from wastewater.

Hierarchical Hydroxyapatite Microspheres Composed of Nanorods and Their Competitive Sorption Behavior for Heavy Metal Ions

2012 ◽  
Vol 2012 (16) ◽  
pp. 2665-2668 ◽  
Author(s):  
Ronghai Zhu ◽  
Xiaoyong Lai ◽  
Jonathan E. Halpert ◽  
Ranbo Yu ◽  
Dan Wang
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Sorption Behavior ◽  
Competitive Sorption

scholarly journals Efficient Removal of Heavy Metal Ions in Wastewater by Using a Novel Alginate-EDTA Hybrid Aerogel

2019 ◽  
Vol 9 (3) ◽  
pp. 547 ◽  
Author(s):  
Min Wang ◽  
Zhuqing Wang ◽  
Xiaohong Zhou ◽  
Shikun Li
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Heavy Metal Ions ◽  
Maximum Adsorption Capacity ◽  
Adsorbent Regeneration ◽  
Acid Washing ◽  
Washing Process ◽  
Repeated Use ◽  
Hybrid Aerogel

In this study, we prepared a novel calcium alginate-disodium ethylenediaminetetraacetate dihydrate hybrid aerogel (Alg-EDTA) by chemical grafting and vacuum-freeze-drying to remove heavy metal ions from wastewater. Experimental results show that the as-prepared Alg-EDTA adsorbent has a high affinity for heavy metal ions, such as Cd2+, Pb2+, Cu2+, Cr3+, and Co2+, and can adsorb >85% of metal ions from the corresponding solution. Alg-EDTA also exhibits high selectivity toward Cd2+, and the maximum adsorption capacity for Cd2+ reached 177.3 mg/g, which exceeds the adsorption capacity of most reported Cd2+-adsorbents. Adsorbent regeneration can be achieved by a simple acid-washing process, and adsorption performance of Alg-EDTA remains stable after repeated use. All these findings indicate that Alg-EDTA has a promising prospect in the treatment of heavy metal ions wastewater.

Adsorption performance of a polysaccharide composite hydrogel based on crosslinked glucan/chitosan for heavy metal ions

2019 ◽  
Vol 169 ◽  
pp. 45-54 ◽  
Author(s):  
Chenglong Jiang ◽  
Xiaohong Wang ◽  
Ganghu Wang ◽  
Chen Hao ◽  
Xin Li ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Composite Hydrogel ◽  
Adsorption Performance

A Mesoporous Chelating Polymer-Carbon Composite for the Hyper-Efficient Separation of Heavy Metal Ions

2020 ◽  
Vol 20 (5) ◽  
pp. 3042-3046 ◽  
Author(s):  
Jukyoung Kang ◽  
Tack-Jin Kim ◽  
Jong Won Park ◽  
Kyo-Young Lee ◽  
Doh Hee Park ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Mesoporous Carbon ◽  
Heavy Metal Ions ◽  
Carbon Composite ◽  
Maximum Adsorption Capacity ◽  
Absorption Data ◽  
Public Health Perspective ◽  
Chelating Polymer

The removal of heavy-metal ions from wastewater is an important objective from a public-health perspective, and chelating agents can be used to achieve this aim. Herein, we report the synthesis of mesoporous carbon as a chelating polymer host using nanoarchitectonics approach. Carboxymethylated polyethyleneimine, a chelating polymer, was incorporated into the mesopore walls of mesoporous carbon to create a polymer-mesoporous-carbon composite. Nitrogen adsorption– desorption experiments and scanning electron microscopy (SEM) were used to illustrate the structural advantages of the composite. Co2+ adsorption by the composite material was examined using cobalt nitrate solutions at pH 3. The study revealed that the Co2+-absorption data are most closely modeled by the Langmuir isotherm. The maximum adsorption capacity, calculated by linear regression, was determined to be about 40 mg-Co/g-composite at pH 3. The composite exhibited about a six-times higher adsorption capacity toward a dilute Co solution (12.5 ppm) than that of the pristine mesoporous carbon. In addition, the composite showed a substantially higher distribution coefficient (Kd = 1.54×105) compared to that (Kd = 2.05×102) of the mesoporous carbon. Overall, we expect that the mesoporous composite, with its large mesopores (~20 nm), will be in high demand for adsorption applications.

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