Study on Metal Ion Adsorption of Bifunctional Chelating/Ion-Exchange Resins

Abstract

Ion‐exchange resin has been considered as a suitable material for the recovery of heavy metals in water treatment. The chelating group, iminodiacetic acid (—R—N(CH2COOH)2), was introduced into the weak‐acid type (—R(COOH)—)n—) ion‐exchange resin to obtain bifunctional ion‐exchange resins. Chromic, cupric, cadmium and lead ions were employed for adsorption experiments in this study. In isothermal experiments, the order of heavy metal ion adsorption decreased with increasing diameter of the heavy metal ion when the chelating group content was less than half. On the contrary, the adsorbed amount of lead ion would be higher than that of cadmic ion as the quantity of chelating group content was more than half owing to the stability constant difference (Ks[Pb2+] = 1017.5 > Ks[Cd2+] = 105.71 in iminodiacetic acid). The adsorption efficiency of bifunctional ion‐exchange resins, especially for lead ions, would increase with rising chelating group content (from 0.08 mmol/mmol COOH to 0.31 mmol/mmol COOH). Meanwhile, the working pH range for metal ion adsorption in bifunctional ion‐exchange resins was extended from 2.5 down to 0.5. Addition of chelating groups to weak acid ion‐exchange resins could increase the adsorption efficiency for metal ions owing to the increased free volume of polymer structure.

Effect of chelating functional polymer on the size of CdS nanocluster formation

“…Reaction temperature was 75 • C, controlled by a thermostatic water bath. Glycidyl methacrylate (GMA) was reacted with iminodiacetic acid (IDA) to produce the monomer (2-methylacrylic acid 3-(biscarboxymethylamino)-2-hydroxy-propyl ester) (GMA-IDA) [14]. MA was added to the reaction flask, followed by potassium sulfate (K 2 S 2 O 8 , Aldrich Co.) as a polymerization initiator, yielding poly(MA-co-GMA-IDA) microspheres in latex form.…”

“…In the authors' earlier work, the strongly N-chelating copolymer poly(acrylates-co-2-methylacrylic acid 3-(bis-carboxymethylamino)-2-hydroxypropyl ester) was prepared by soap-free emulsion polymerization and used to treat the metal ion waste water, etc. [14][15][16]. In our present study, we use a similar chelating comonomer for production of hybrid composite CdS Q-dots chelated onto copolymer microspheres of poly(acrylates-co-2-methylacrylic acid 3-(bis-carboxymethylamino)-2-hydroxy-propyl ester), i.e., onto poly(MA-co-GMA-IDA) microspheres.…”

Adsorption of heavy metal ions and azo dyes by crosslinked nanochelating resins based on poly(methylmethacrylate-co-maleic anhydride)

“…Two strong absorption bands at 1401 and 1544 cm -1 are observed in the spectrum of [Hg-(Co-g-AP 3 )] complex, which are assigned to the symmetric (vs, COO -) and asymmetric (vas, COO -) vibration absorption of the carboxylic groups, respectively [25]. The shift of FT-IR peak for the carbonyl group of carboxylate could indicate whether the bonding between the ligand and metal ion was covalent or ionic [26]. In this study, there is small shift towards higher frequency which can be taken as evidence for formation of covalent bond between metal ions and carbonyl groups.…”

Synthesis of yttrium iron garnet using polymer–metal chelate precursor

“…Reaction temperature was 75 • C, controlled by a thermostatic water bath. GMA was reacted with iminodiacetic acid (IDA) to produce the chelating monomer (2-methylacrylic acid 3-(bis-carboxymethylamino)-2-hydroxypropyl ester) (GMA-IDA) [10]. BA (0.26 M), GMA (0.07 M), and GMA-IDA (0.06 M) were added to the reaction flask, followed by potassium sulfate (KPS, K 2 S 2 O 8 , Aldrich Co.) (0.36 mM) as an initiator, yielding poly(BA-co-GMA-co-GMA-IDA) microspheres in latex form (average particle diameter ca.…”

“…Because this kind of chelating polymer was polymerized using a vinyl chelating monomer that is manufactured by our laboratory [10], one can easily prepare different polarities of chelating copolymer by adding hydrophilic or hydrophobic vinyl monomers. Thus, following the different co-monomer additives, two types of chelating polymer, water-soluble and water-insoluble, were synthesized in this text to study the formation mechanism of YIG preparation from homogeneous and heterogeneous nucleation, respectively.…”