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.

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.

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 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 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.

Adsorption capacity of hydroxyapatite for several amino acids and heavy metal ions

2012 ◽  
Vol 46 (5) ◽  
pp. 292-294 ◽  
Author(s):  
A. S. Berlyand ◽  
A. P. Snyakin ◽  
A. A. Prokopov
Keyword(s):  
Amino Acids ◽  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Heavy Metal Ions

scholarly journals Competitive adsorption and mechanism of hexahydroxy metallic system by aminated solution-blown polyacrylonitrile micro/nanofibers

2021 ◽  
Author(s):  
Huiqing Lou ◽  
Siyu Li ◽  
Xiangwei Feng ◽  
Xianzhong Cao
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Metal Ion ◽  
Metal Removal ◽  
Interactive Effect ◽  
Maximum Adsorption Capacity ◽  
Coupling Mechanism ◽  
Metal System ◽  
Metallic System

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.

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