Trace metal ion retention properties of crosslinked poly(4‐vinylpyridine) and poly(acrylic acid)

Abstract

ABSTRACT:The crosslinked resins poly(4-vinylpiridine) (PVPy) and poly(acrylic acid) (PAA) were obtained by radical polymerization. PVPy shows monodentate ligands and PAA at basic pH is basically as acrylate anion, which can contain end-carboxylates groups or form a bridge acting as mono-or bidentate ligands. The retention properties for trace metal ions from saline aqueous solutions and natural seawaters of these two resins were investigated by Batch equilibrium procedure. The metal ions studied were Cu(II), Pb(II), Cd(II), and Ni(II). The following effects were studied: pH, contact time, amount of the adsorbent, temperature, and salinity. The resin PVPy showed a high affinity for Cd (II) and PAA for Cu(II) and Cd(II). The metal ions were determined in the filtrate by atomic absorption spectrometry. By the treatment of the loaded resin with 4M HNO 3 , it was possible to remove completely the Cu(II) ions. The retention properties of the resins were studied for trace metal ions present in the natural seawaters. Both resins showed a high affinity for Cd(II) when the natural seawater contained Cu(II) and Cd(II).

Regeneration of anion‐exchange resins with Mg/Al double‐metal hydroxides

“…Figure 4 shows the breakthrough curves with different dosages of Mg/Al hydroxides with an Mg/Al molar ratio of 3. The different dosages of Mg/Al hydroxides regenerated the fouled resin under pneumatic agitation, and the effluent water volume (conductivity < 300 ls/cm) reached 2.7-3.1 L. The effluent water yield was the highest at 42 times the mixed resin bed volume when Mg(OH) 2 and Al(OH) 3 were 0.045 and 0.015 mol, respectively, compared with those of the other dosages of Mg/Al hydroxides.…”

“…Mg(OH) 2 and Al(OH) 3 and NaOH, and Mg 21 and Al 31 were maintained at a certain molar ratio. The Mg(OH) 2 and Al(OH) 3 sols were rinsed until a conductivity of less than 100 ls/cm was obtained.…”

“…The fouled 201 3 7 type AERs were also rinsed until a conductivity of less than 100 ls/cm was achieved. Mg(OH) 2 , Al(OH) 3 , and the AERs were placed into a self-made ion-exchange Plexiglas column (50 mm diameter and 400 mm height) connected to a circulating-water vacuum pump and buffer, as shown in Figure 1. Pneumatic agitation was conducted for 3 h at room temperature.…”

“…1,2 Anion-exchange resins (AERs) have been widely applied in the fields of water treatment, food, metallurgy, and nuclear industries [3][4][5][6][7] to remove inorganic salts 8,9 and organic compounds 10,11 in water. After ion exchange for a specific time, the reticular structure of the resin skeleton is obstructed by organic compounds 12 in most ion states and part of the colloidal state of water.…”

Crystalline polymer decoration on multiwalled carbon nanotubes: MWCNT-induced P4VP periodic crystallization in CO2-expanded liquids

“…P4VP is so intriguing material and there are several reasons for choosing it as our functional polymer. First of all, it has reactive pyridine group for coordinative with transition metals, which can be widely used in the field of catalysis [20][21][22][23], humidity sensitive material [24], waste water treatment [25,26] and also as a host ligand of metal-containing chromophores [27,28]. Moreover, its solution behavior can be changed significantly, being a hydrophobic polymer in apolar solvents and a cation polyelectrolyte in water at low pH [29,30].…”