Facet-Dependent Selective Adsorption of Mn-Doped α-Fe2O3 Nanocrystals toward Heavy-Metal Ions

2017 ◽  
Vol 29 (23) ◽  
pp. 10198-10205 ◽  
Author(s):  
Qinglin Yuan ◽  
Pengfei Li ◽  
Jun Liu ◽  
Yue Lin ◽  
Yunyu Cai ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Selective Adsorption ◽  
Mn Doped

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 Insight into the Synergistic Effect on Selective Adsorption for Heavy Metal Ions by a Polypyrrole/TiO2Composite

Langmuir ◽  
2018 ◽  
Vol 34 (34) ◽  
pp. 10187-10196 ◽  
Author(s):  
Jie Chen ◽  
Mengting Yu ◽  
Caiyun Wang ◽  
Jiangtao Feng ◽  
Wei Yan
Keyword(s):  
Heavy Metal ◽  
Synergistic Effect ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Selective Adsorption ◽  
Insight Into

Thermoresponsive Ion-Imprinted Hydrogels with Interpenetrating Network Structure for Removal of Heavy Metal Ions

2013 ◽  
Vol 643 ◽  
pp. 83-86 ◽  
Author(s):  
Jing Jing Wang ◽  
Fang Liu
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Network Structure ◽  
Heavy Metal Ions ◽  
Selective Adsorption ◽  
Triethylene Glycol ◽  
Solution Temperature ◽  
Interpenetrating Network ◽  
Ion Imprinted ◽  
Ion Imprinting

A novel thermoresponsive Cu(II) ion-imprinted hydrogel [Cu(II)-IIH] with interpenetrating network structure has been prepared to remove Cu(II) ions with high selectivity. The Cu(II)-IIH was prepared by free radical/cationic hybrid photopolymerization of N-isopropylacrylamide (NIPAM) and triethylene glycol divinyl ether (DVE-3) using Cu(II) ion as template. The Cu(II)-IIH was used to remove heavy metal ions from aqueous solution at 20 and 40oC. The Cu(II)-IIH selectively bound the template ion above a lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) (PNIPAM). The memory was fixed by shrinking above the LCST, and was deleted by swelling below the LCST. Selective adsorption study indicated that ion imprinting resulted in stronger affinity of the Cu(II)-IIH toward Cu(II) ions than other competitor metal ions compared with the non-imprinted hydrogel (NIH).

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.

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