Chitosan@Succinic acid: A green adsorbent for Diclofenac removal from wastewaters

Over the last few decades, scientists have focused on chitosan modification [1]. Chitosan is a natural cationic polymer that is low-cost, non-toxic, biodegradable, and offers antimicrobial and adsorbent properties [2]. Moreover, chitosan provides two different functional groups, -NH₂ and -COOH, that create new chemical bonds with other smaller chemical compounds to improve mechanical properties and adsorption capacity. Many researchers have studied the modification of chitosan with dicarboxylic acids such as itaconic acid [3], citric acid[4], and malonic acid [5]. In this study, the modification of chitosan with tricarboxylic acid and succinic acid was tested. In the literature, numerous research articles refer to the chitosan modification with succinic anhydrate [6]^,[7]. However, succinic acid is less toxic (it is a GRAS-approved food additive by the FDA) [8] than succinic anhydrate, and this makes the new adsorbent Chitosan@Succinic acid more environmentally friendly. In this work, CS@SA was synthesized and characterized via FTIR and XRD techniques. Thereafter, CS@SA was investigated for the removal of diclofenac. Batch experiments concluded the effect of pH, kinetics, and isotherm studies.

Acknowledgment: We acknowledge support of this work by the project “Advanced Nanostructured Materials for Sustainable Growth: Green Energy Production/Storage, Energy Saving and Environmental Remediation” (TAEDR-0535821) which is implemented under the action “Flagship actions in interdisciplinary scientific fields with a special focus on the productive fabric” (ID 16618), Greece 2.0—National Recovery and Resilience Fund and funded by European Union NextGenerationEU.