Synthesis and Characterization of a New Polyamide Network for Use as Cu2+ Adsorbent from Aqueous Media

Water contamination with toxic ions has become a great environmental problem. Among toxic metal ions, copper is a micronutrient element and play an important role in the bone formation together with certain proteins and enzymes. But, it is considered a hazardous pollutant when it cannot be maintained at an appropriate physiological concentration. Cu2+ ions have been introduced from several industrial wastewaters. Therefore a simple, reliable, selective and sensitive method for Cu2+ monitoring and removal is important for environmental safety and health [1]. Various methods and technologies have been developed and reported for effective removal of Cu2+ from aqueous solutions. Among these methods, adsorption with a chelating resin containing amino and carboxyl groups has attracted considerable research interest in recent years due to advantages of achieving high efficiency, good selectivity, reusability and relatively low cost [2]. There are several groups of chelating agents that contain carboxylate functional groups bound to one or more nitrogen atoms and have the ability to sequester metal ions. Therefore, surface functionalization with these high affinity binding groups has received considerable research interests in the recent years [3]. In this work, firstly 2, 6-dimethyl-3, 5-pyridinedicarboxhydrazide (DMPDCH) was synthesized using the Hantzsch pyridine synthesis followed by reacting with hydrazineaccording to Figure 1. Then a novel polyamide network was prepared by condensation polymerization of the DMPDCH with citric acid (CA). The prepared poly (DMPDCH-co-CA) was used as chelating agent to remove Cu2+ from aqueous solutions. Different parameters were investigated to obtain optimized condition. Results showed acceptable efficiency for the prepared resin. The structural characterization of the resin was studied using FT-IR, TGA and SEM analyses.