Preparation and characterization of hydroquinone based polyoxalate and its application in the removal of heavy metals from water

Abstract

Hydroquinone based polyoxalate was synthesized from oxalyl chloride and hydroquinone. The polymer was characterized with FTIR, 1H-NMR, 13C-NMR, PXRD, SEM and thermal analysis. The chelation behaviour of the polymer towards Pb(II), Cd(II), and Hg(II) in aqueous solutions was studied by batch technique as a function of contact time and pH. The polymer showed high metal uptake toward Pb(II) and Cd(II) and moderate metal uptake toward Hg(II). The adsorption capacity was not affected by the pH of solution. The adsorption data were fitted with second order kinetic model and the isotherms models of Langmuir and Freundlich. Thermodynamics measurements showed that sorption process was spontaneous. Furthermore, the chelating polymer was loaded with metal ions using fixed bed column. For regenerating the loaded polymer, different eluting agents include HNO3, H2SO4, and EDTA was investigated. The highest recovery of metal ions was achieved using HNO3, indicating that desorption process was governed by the solubility factor and cation exchange mechanism.

Light‐Triggered Structural Modulation of Nanofibrous Meshes to Promote Deep Penetration of Cultured Cells

“…Previous studies also reported similar bands at ≈1700–1800 cm −1 in the FTIR spectra of valsartan‐loaded POX microspheres or poly(1,4‐phenylene oxalate). [ 33,39 ] On the other hand, while POX NFs with and without laser irradiation, as well as POX/Ce6 NF without laser irradiation, did not exhibit any changes in the FTIR spectrum, the band intensity of POX/Ce6 with the laser irradiation spectrum significantly decreased (except for the CN band at 1162 cm −1 that indicated the presence of Ce6 molecules in the NF mesh). The enlarged image in Figure 2a denotes the reduced intensity of the C═O band at ≈1700 cm −1 , which could be attributed to the degradation of oxalate groups in POX under the effect of ROS released from Ce6 when irradiated with laser.…”

Synthesis and Characterization of Poly (1,4-Benzenedimethylene Phthalate) and the Study of its ability to sorb Pb(II), Cd(II), and Zn(II) ions

“…The trend in qm values for poly(1,4cyclohexanedimethylene oxalate) at pH= 4.00 and 25.0 oC is Pb(II) > Cd(II) > Zn(II), in (mg/g) were 31.2 > 29.8 > 15.9, respectively [19]. The trend for Pb(II) and Cd(II) ions in poly(hydroquinone oxalate), and in poly(neopentyl oxalate) polymer, were as follows: Pb(II)>Cd(II) [24][25][26][27] and thus the results similar in order the metal ion with our results in the literature [23] that is q m values 207.7 >30.7 >19.1 for Pb(II) >Zn(II) >Cd(II) in poly(bisphenol A oxalate).…”