Adsorption of Hg(Ⅱ) from aqueous solution using thiourea functionalized chelating fiber

A fast and selective adsorbent for Hg（ll） from aqueous solutions using thiourea （TU） functionalized polypropylene fiber grafted acrylic acid （PP-g-AA）, PP-g-AA-TU fibers, was characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The adsorption behavior of the functionalized chelating fibers for Hg（Ⅱ） was investigated by static adsorption experiments, and the effects of some essential factors on adsorption of Hg（Ⅱ） were examined, such as pH, initial concentration, adsorption time, coexisting cations, and temperature, The results showed that the adsorptive equilibrium could be achieved in 10 min, and the equilibrium adsorption quantity of PP-g-AA-TU fibers was 20 times that of PP-g-AA fibers. The PP-g-AA-TU fibers showed a very high adsorption rate and a good selectivity for Hg（Ⅱ） over a wide range of pH. The adsorption isotherm can be well described with Langmuir model, with the maximum adsorption capacity for Hg（Ⅱ） up to 52.04 mg.g-1 and the removal of Hg（Ⅱ） more than 97%. The kinetic data indicate that the adsorption process is best-fitted into the pseudo-second-order model.

Preparation of new hyper cross-linked chelating resin for adsorption of Cu^(2+) and Ni^(2+) from water

The new hyper cross-linked chelating resin NDWJN2 modified with carboxyl groups was prepared for removal of Cu^（2＋） and Ni^（2＋） from water.NDWJN2 was characterized using BET,SEM and FT-IR spectroscopy.Comparing with commercial resins D113 and IRC84,NDWJN2 could remove Cu^（2＋） and Ni^（2＋） from water more effectively.Langmuir model could fit adsorption isotherms well.

Chelating Properties of Salicylhydroxamic Acid-functionalized Polystyrene Resins and Its Application to Efficient Removal of Heavy Metal Ions from Aqueous Solutions

Salicylhydroxamic acid（SHA） was covalently bound onto crosslinked polystyrene spheres（CPSs） via the Friedel-Crafts alkylation reaction between chloromethylated CPSs and SHA in the presence of SnCI4 as the Lewis acid catalyst. The resulted SHA-CPSs possessed very strong chelating ability for heavy metal ions. In particular, the saturated adsorption amount of SHA-CPSs for Cu2＋ ions could reach as high as 34.2 mg/g at 318 K. The chelating capability of SHA-CPSs towards heavy metal ions was pH and temperature dependent. SHA-CPSs also showed se- lective metal coordination with the chelating capacity decreasing in the order of Cu2＋ 〉Zn2＋〉〉Pb2＋. The adsorption isotherms conformed well to the Langmuir model, and the adsorption process was found to be entropy-driven and endothermic. Besides, SHA-CPSs possessed the excellent reusability.

Optimization of polyacrylonitrile-cysteine resin synthesis and its selective removal of Cu(Ⅱ) in aqueous solutions

Polyacrylonitrile beads（PAN） cysteine（CS） was synthesized from polyacrylonitrile beads（PAN） and cysteine（CS）.The content of the functional group and the percentage conversion of the functional group of PAN-CS prepared under the optimum condition using response surface methodology（RSM） for the first attempt were 3.22 mmol/g and 35.78%.The structure was characterized by ET-IR and elemental analysis.The adsorption properties of the resin for Cu（Ⅱ） were investigated by batch and column experiments.Batch adsorption results suggested that PAN-CS had higher adsorption capability for Cu（Ⅱ）than other metal ions and maximum saturated adsorption capacity was 184.7 mg/g.The resin and its metal complexes were studied by FT-IR.Furthermore,the resin can be eluted easily using 1 mol/L HC1.PAN-CS can provide a potential application for selective removal of copper from waste solution.

Preparation and application of a novel orotic acid chelating resin for removal of Cu(Ⅱ) in aqueous solutions

A novel chelating resin OABA,capable of removing Cu（Ⅱ） from aqueous solution,was synthesized via the reaction of macroporous chloromethylated PS-DVB copolymer beads with orotic acid.The elemental analysis（EA）,Fourier transform infrared spectroscopy（FT-IR）,and scanning electron microscopy microscope-energy dispersive X-ray spectroscopy（SEM-EDS） were used in the characterization of the synthesized chelating resin.Multiple,static batch adsorption experiments were conducted at different initial concentrations and temperatures.OABA showed good adsorption capacity for Cu（Ⅱ） and the equilibrium data could be well matched with the Freundlich isotherm model.Coexisting sodium chloride and calcium chloride in solutions favored the Cu（Ⅱ） adsorption.Moreover,the desorption process of Cu（Ⅱ） was tested and over 90%regeneration efficiency for the spent OABA was achieved at ammonia concentrations ranging from 1.0%to 2.0%.The results suggested that OABA would be a potential alternative adsorbent for Cu（Ⅱ）,even with other heavy metal ion treatments of wastewater.