Thermoresponsive Ion-Imprinted Composite Hydrogels for Heavy Metal Ion Removal

A novel thermoresponsive Cu(II) ion-imprinted composite hydrogel [Cu(II)-IICH] based on N-isopropylacrylamide (NIPAM) and aminated silica (SiO2-NH2) has been prepared by in situ free-radical polymerization using Cu(II) ion as template. The Cu(II)-IICH was used to remove heavy metal ions from aqueous solution at 20 and 40oC. The Cu(II)-IICH selectively bound the template ion above a critical gel transition temperature (CGTT) of crosslinked poly(N-isopropylacrylamide) (PNIPAM). The memory was fixed by shrinking above the CGTT, and was deleted by swelling below the CGTT. In order to study the reusability of the Cu(II)-IICH, the sorption-desorption cycles were performed for five times. The results suggested that the Cu(II)-IICH can be used for several times without significantly decreasing its adsorption capacity.

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Removal of Heavy Metal Ions with Hacac-Silica

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.901.45 ◽

2014 ◽

Vol 901 ◽

pp. 45-51

Author(s):

Dan Feng Cui ◽

Jian Zhuang Zhao ◽

Yan Ying Zheng

Keyword(s):

Heavy Metal ◽

Metal Ions ◽

Metal Ion ◽

Heavy Metal Ions ◽

High Specific Surface Area ◽

Metal Ion Removal ◽

Ion Removal ◽

Ultrasonic Technology ◽

Heavy Metal Ion Removal

This paper presents a new decoration view functionalization of mesoporous silica to extend their applications to heavy metal ion removal. The study showed that Hacac can be incorporated into the structure through in-situ strategy, and the calcined Hacac-silica possesses advantages of high specific surface area of about 1496 m2/g and pore size of 4nm, ordered spheric morphology of about 300nm in diameter. Auxiliary by ultrasonic technology, the heavy metal ions remove rates are more than 95% for Pb2+, Cu2+ and Cr3+. More choice of chelating agents can be used for further functionalization of silica based mesoporous material.

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Effect of Different Chemical and Physical Characteristic Having Lignocellulosic Fibers on Heavy Metal Ion Removal from Auqueous Solution

Materials Science Forum ◽

10.4028/www.scientific.net/msf.569.285 ◽

2008 ◽

Vol 569 ◽

pp. 285-288 ◽

Cited By ~ 2

Author(s):

Hyun Jong Lee ◽

Beom Goo Lee ◽

Dae Yong Shin ◽

Heon Park

Keyword(s):

Heavy Metal ◽

Metal Ions ◽

Metal Ion ◽

Heavy Metal Ions ◽

Heavy Metal Ion ◽

Metal Ion Removal ◽

Ion Removal ◽

Lignocellulosic Fibers ◽

Heavy Metal Ion Removal ◽

Kenaf Bast

In this study lignocellulosic fibers, such as kenaf bast, kenaf core, sugar cane bagasse, cotton, coconut coir, and spruce, which are environment friendly natural materials, were tested for their ability to remove copper, nickel and zinc ions from aqueous solutions. The fibers were analyzed for Klason lignin content, water sorption capacity and dry volume. The fiber with the highest level of heavy metal removal in the separate and mixed solution was kenaf bast.. In the mixed solution kenaf bast, sugar cane bagasse and cotton removed more copper and nickel ion than in the separate solution, and the amounts of removed heavy metal ions were changed in some lignocellulosic fibers, compared to those of the separate solution. In the mixed solution heavy metal ions may compete with one another for sorption sites on the surface of lignocellusic fiber. In kenaf bast to remove heavy metal ions most, Klason lignin content was the second lowest, and water sorption and dry volume were the lowest in all tested lignocellulosic fibers. It showed that removal of heavy metal ions does not correlate with any chemical and physical factors, but may be affected by the cell wall structure of lignocellulosic fibers and how many free phenolic groups in lignin, which are considered as the heavy metal ion binding site, are exposed on the surface of fibers. Cotton, with about 1% Klason lignin, was very low in heavy metal ion removal, while all other fibers containing greater than about 10% lignin did remove heavy metal ions. It showed that even the lignin content of lignocellulosic fibers does not correlate with heavy metal ion removal but lignin does play a role in heavy metal ion removal.

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Selective Removal of Toxic Ions from Water/Wastewater: Using a Novel Surfactant

Substantia ◽

10.36253/substantia-830 ◽

2021 ◽

pp. 79-88

Author(s):

Mohammad Ziaee ◽

Mojtaba Taseidifar ◽

Richard M. Pashley ◽

Barry W. Ninham

Keyword(s):

Heavy Metal ◽

Metal Ions ◽

Metal Ion ◽

Heavy Metal Ions ◽

Toxic Heavy Metal ◽

Metal Ion Removal ◽

Ion Removal ◽

Advantages And Disadvantages ◽

Heavy Metal Ion Removal ◽

Green Surfactant

Pollution of drinking water by toxic heavy-metal ions is a matter of concern worldwide. These ions occur naturally, and also from environmental spills, radioactive wastes and other industrial waste. Arsenic and lead are typical examples. A novel green surfactant, purpose designed, and environmentally friendly is shown to be extremely effective and specific for heavy metal ion removal. This is a considerable step forward on previous technologies. Surfactants have been used universally to remove organic and inorganic contaminants from water. But little selectivity has been achieved. After usage, the residual surfactants are discharged into surface waters or sewage systems. This causes environmental pollution. In this review, three surfactants from different classes (novel green surfactant, synthetic chemical surfactant and biosurfactant) are compared in terms of their efficiency in flotation, removal of different heavy-metal ions, biodegradability, and toxicity level, including their advantages and disadvantages.

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