Calixarene-based extractants for heavy metal ions removal from aqueous solutions

Abstract

A hyper-crosslinked resin chemically modified with thiourea (TM-HPS) was synthesized, characterized, and evaluated for the removal of heavy metal ions (Pb 21 , Cd 21 , and Cu 21) from aqueous solutions. The structural characterization results showed that a few thiourea groups were grafted on the surface of the resin with a big BET surface area and a large number of narrow micropores. Various experimental conditions such as pH, contact time, temperature, and initial metal concentration of the three heavy metal ions onto TM-HPS were investigated systematically. The results indicated that the prepared resin was effective for the removal of the heavy metal ions from aqueous solutions. The isotherm data could be better fitted by Langmuir model, yielding maximum adsorption capacities of 689.65, 432.90, and 290.69 mg/g for Pd 21 , Cd 21 , and Cu 21 , respectively. And the adsorption kinetics of the three metal ions followed the pseudo-second-order equation. FTIR and XPS analysis of TM-HPS before and after adsorption further revealed that the adsorption mechanism could be a synergistic effect between functional groups and metal ions and electrostatic attraction, which may provide a new insight into the design of highly effective adsorbents and their potential technological applications for the removal of heavy metal ions from aqueous solutions.

1,3-Diketone Calix[4]arene Derivatives—A New Type of Versatile Ligands for Metal Complexes and Nanoparticles

“…Calix[4]arenes, thiacalix[4]arenes and calix[4]resorcinarenes are the most widely applied scaffolds among other calix[n]arenes for embedding of different groups [ 12 , 13 , 14 , 15 ]. The stability of a cone -conformation, in turn, opens new opportunities for the preorganization of functional groups, which is of great advantage in developing of ligands and extractants [ 16 , 17 , 18 ]. The 1,3-diketone derivatives have been well-documented as both promising precursors in organic synthesis [ 19 , 20 ] and as promising compounds in drug design [ 21 , 22 ], although the greatest attention has been focused on their complex ability [ 23 ].…”

Luminescence Properties of Self-Aggregating TbIII-DOTA-Functionalized Calix[4]arenes

“…Calix[4]arenes were initially proposed as artificial enzyme mimics in the late 70s (Gutsche and Muthukrishnan, 1978 ) and today represent versatile building blocks with potential for application in industrial, technical and biomedical fields, ranging from wastewater treatment (Konczyk et al, 2016 ) to medical imaging (Schühle et al, 2011 ; Sreenivasu Mummidivarapu et al, 2015 ). The multifunctional constitution of calix[4]arenes consists of four phenol moieties forming a cup-shaped structure with an upper and a lower rim .…”

Calix[4]arene‐Based n‐Dialkylamino Extractants for Selective Platinum Group Metal Separation from Automotive Catalysts

“…To them, we can introduce, in an orderly fashion, a variety of functional groups that possess high affinity for transition metals, PGMs, and rare earth metals . Calixarene‐based extractants have been widely used for the removal of heavy metal ions from aqueous solutions . For example, Yordanov et al.…”

“…[17][18][19][20][21] Calixarene-based extractants have been widely used for the removal of heavy metal ions from aqueous solutions. [22] For example, Yordanov et al synthesized "upper" and "lower" rim functionalized calix - [4]arenes and studied their ability to extract transition metals, gold, and PGMs. [23][24][25] Kostin and coworkers used many sulfurcontaining calix [4/6]arenes for the extraction of PGMs from hydrochloric acid solutions.…”