Synthesis and characterisation of zinc oxide modified biorenewable polysaccharides based sustainable hydrogel nanocomposite for Hg2+ ion removal: Towards a circular bioeconomy

Industrial metal ion pollution has been considered the chief source of water contaminants all over the world. In the present research, we have prepared gum tragacanth cross-linked 2-hydroxyethyl methacrylate-co-acrylamide (GT-cl-(HEMA-co-AAm)) hydrogel and gum tragacanth cross-linked 2-hydroxyethyl methacrylate-coacrylamide/zinc oxide (GT-cl-(HEMA-co-AAm)/ZnO) hydrogel composite with better Hg2+ adsorption capability. GT-cl-(HEMA-co-AAm)/ZnO hydrogel composite (154.8 mg g(-1)) exhibited higher Hg2+ adsorption than GT-cl-(HEMA-co-AAm) hydrogel. To address the performance of GT-cl-(HEMA-co-AAm) hydrogel and GT-cl(HEMA-co-AAm)/ZnO hydrogel composite, batch adsorption experiments were successfully conducted under different optimised conditions. At last, in-vitro antibacterial activities of Hg2+ loaded GT-cl-(HEMA-co-AAm) and GT-cl-(HEMA-co-AAm)/ZnO were performed in two different well Staphylococcus aureus (gram-positive) and Pseudomonas aeruginosa (gram-negative) bacteria. As a positive control, ampicillin was employed against both types of bacteria. This methodology for the reusability of material has a great ecofriendly impression for minimising secondary waste derived from adsorption and can help design upgraded antibacterial agents.

Automated summary

This study prepared hydrogel materials with improved adsorption capability for Hg2+, which is an important step towards addressing industrial metal ion pollution. The hydrogel composite showed higher adsorption capacity compared to the single hydrogel material. Furthermore, the material exhibited promising antibacterial activity in vitro, suggesting its potential as an upgraded antibacterial agent.