Application of chitosan-citric acid variant resins in the cyclic sorption-desorption of toxic ions from Zn dominant Adsorbate system

Abstract

Targeted sorbents for the real-world adsorptive separation of heavy metals shall exhibit high sorption capacity, reusability, and cost-effectiveness. In this study, a novel composite sorbent has been synthesized for the concurrent mitigation of iron, lead, and zinc metal ions from synthetic wastewater systems. For this purpose, chitosan with alternate molecular weight (low, medium, and high) and with hydroxyl and amine functional groups was employed as a substrate. The successful anchoring of the organic compound citric acid was achieved with the glutaraldehyde crosslinker. The work focused on the concurrent elimination of iron, lead, and zinc ions under diverse conditions of sorbent dose (0.2 to 2 g L− 1), initial concentration (194.9-584.7 mg L− 1, 2.65–7.95 mg L− 1, and 104.8-314.4 mg L− 1 respectively for zinc, lead, and iron), and adsorbent contact duration (5 to 720 min). Accordingly, it was ascertained that other alternative ions in the adsorbate system significantly alter the sorption patterns. Following this, the desorption of metal ions was effective with simple basic and acidic eluents and for a three-cycle-based simultaneous regeneration. In summary, the findings demonstrate the promising performance of the sorbent for metal ions eradication from intricate solutions.