Enhanced Recovery of Pb2+ Ions from Aquatic Media by Using Polyurethane Composite as Adsorbent

Abstract

Elastomeric polyurethane (PU) and its composites (PUN and PUC) with different types of filler were prepared and investigated by differential analysis. Their ability to remove Pb 2+ ions from aqueous solutions was studied. The results indicated that, at high concentration of Pb 2+ ions (500 mg/L), the removal efficiency of Pb 2+ ions by PUC is better than PUN; at low concentration of Pb 2+ ions (125 mg/L), the difference in removals between the two is only slight, i.e., 58.36 % by PUC (0.5 g/L) and 55.11 % by PUN (0.5 g/L). Moreover, PUN exhibited a well-developed site structure, providing adsorption sites for Pb 2+ ions; for this and for cost reasons, we decided to study Pb 2+ ions removal ability of PUN. The results showed that the maximum adsorption capacity of Pb 2+ ions at 125 mg/L concentration at pH 5.0, when using 0.5 g/L of PUN as adsorbent, was 142.85 mg/g. Furthermore, the equilibrium data showed that the adsorption of Pb 2+ ions on PUN obeys a pseudo-second order kinetic model, depending on adsorbent dosage, pH, initial concentration of metal ions and contact time. From these results, it is suggested that PUN adsorbent may be appropriate for the removal of Pb 2+ ions from wastewater.

Filler-Modified Castor Oil-Based Polyurethane Foam for the Removal of Aqueous Heavy Metals Detected Using Laser-Induced Breakdown Spectroscopy (LIBS) Technique

“…In contrary to the hydrophobic surface, which is typical for the vegetable oil-based polyurethane, it formed a barrier that obstructed the adsorbate transport. increased the contact surface [32]. It can be expected that the higher Pb 2+ adsorption can be obtained from the foam modified with filler addition.…”

“…The presence of filler particles, either bentonite, zeolite, or activated carbon, contributed to the formation of a rougher surface. Rough morphology facilitated more interaction with the adsorbent as it increased the contact surface [32]. It can be expected that the higher Pb 2+ adsorption can be obtained from the foam modified with filler addition.…”

“…It has a unique structure, surface area, porosity, and functional groups, which contribute to its adsorption performance of heavy metals [23,24]. The addition of AC into the PUF matrix gave a result of rougher surface and higher water absorption, which was expected to be a good filler for facilitating higher Pb 2+ adsorption [32]. Unfortunately, based on the spectral analysis in Figure 7a,b, COPUF modified with AC filler (AC/COPUF) gave the worst adsorption performance among the three modified foams.…”