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
Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4066
Author(s):  
Xianyuan Fan ◽  
Hong Liu ◽  
Emmanuella Anang ◽  
Dajun Ren

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.


2017 ◽  
Vol 29 (23) ◽  
pp. 10198-10205 ◽  
Author(s):  
Qinglin Yuan ◽  
Pengfei Li ◽  
Jun Liu ◽  
Yue Lin ◽  
Yunyu Cai ◽  
...  

2013 ◽  
Vol 643 ◽  
pp. 83-86 ◽  
Author(s):  
Jing Jing Wang ◽  
Fang Liu

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).


2014 ◽  
Vol 2 (14) ◽  
pp. 5034-5040 ◽  
Author(s):  
Zhihui Dong ◽  
Dong Wang ◽  
Xia Liu ◽  
Xianfeng Pei ◽  
Liwei Chen ◽  
...  

By utilizing the synergistic effect of poly-dopamine (PD) with functional groups and graphene oxide (GO) with a high surface area, a series of sub-nano thick PD layer coated GO (PD/GO) composites were fabricated and used for effectively decontaminating wastewater.


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