Work

Novel bifunctional thio-methylene-pyridine grafted polymeric resin for mercury removal from acidic solutions

Year: 2025

Type: article

Abstract: This work brings forth a new ligand grafted onto porous polymeric sorbent beads for selective mercury removal over a wide range of acidity wherein inputs from experimental batch sorption studies, spectroscopic evaluation of the metal-ligand interaction, as well as DFT calculations were obtained to pin down the bi-functional mechanism exhibited by the ligand for Hg2+ sorption. A novel porous solid sorbent, thio-methylene-pyridine (TMP) ligand grafted polymeric resin (TMP resin) was synthesized and tested for sorption of mercury in hydrochloric acid medium. TMP resin showed quantitative sorption of ‘Hg’ in high as well as low acidic solutions (chloride medium) with uptake capacity in the range of 70-80 mg Hg/g, indicating sorption of ‘Hg’ in both cationic and anionic form hence utilizing the bi-functionality of TMP ligand. Spectroscopic investigation on metal-ligand interactions, as well as DFT calculations indicates towards preference for soft-soft co-ordinate complexation at lower acidity and anion exchange of Hg-chloride complex by pyridinium group at higher acidity. Near complete back extraction of from the Hg-loaded sorbent was achieved using 0.1 M thiourea solution at 0.1 M HCl. Resin was regenerated upto 5 cycles of repeated loading and elution wherein there was no appreciable change in the performance with respect to Hg2+ sorption & desorption.

Source: Sustainable Chemistry for the Environment

DOI: 10.1016/j.scenv.2025.100280

Authors: Nikhilesh Iyer, Ritesh Ruhela, Suvarna Saundarajan, Sanjukta Abhay Kumar, Dhruva Kumar Singh

Institutions: Bhabha Atomic Research Centre, Homi Bhabha National Institute

Language: English

Topic: Extraction and Separation Processes

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: gold

Estimated APC paid: $1,440