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.
Highlights
Excessive release of toxic heavy metals into the environment has posed a great problems worldwide [1]
The synthesis of PPO was performed by polycondensation of oxalyl chloride and hydroquinone, the reaction was catalyzed with pyridine as given in Scheme 1
The synthesized polymer was insoluble in most common organic solvents such as chloroform, dimethyl formamide (DMF), tetrahydrofuran (THF) 1,4-dioxane and showed good solubility only in dimethyl sulfoxide (DMSO)
Summary
Excessive release of toxic heavy metals into the environment has posed a great problems worldwide [1]. Many methods have been evaluated for their ability to remove heavy metals from environment resources from the waste-water streams. The backbone of chelating polymers composed active functional groups capable for coordinating with different metal ions. These functional groups usually contain electron donor atoms (Lewis base) such as N, O and S that can coordinate with most of the toxic heavy metals (Lewis acid) [10]. Several criteria are important in the design of chelating polymers include specific and fast metal uptake, high mechanical strength and ability for reusability [11]. In our effort to increase the metal-ion uptake capacity we describe the synthesis and characterization of an aromatic polyoxalate, poly(1,4-phenylene oxalate) (PPO). A real water sample contaminated with heavy metals was studied in order to provide evidence for the applicability of the prepared polymer in wastewater treatment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
