EDTA-Inspired Polydentate Hydrogels with Exceptionally High Heavy Metal Adsorption Capacity as Reusable Adsorbents for Wastewater Purification

Sudipta Panja, Samuel Hanson, Chun Wang

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

Water pollution by heavy metal ions is a critical threat to public health. To remove the heavy metal pollutants from large waterbodies, we have synthesized a biocompatible, cost-effective, metal ion non-specific, and ethylenediaminetetraacetic acid (EDTA)-inspired polydentate hydrogel with exceptionally high adsorption capacity and reusability. The hydrogel was synthesized by the transamidation reaction between hydrolyzed polyacrylamide and branched polyethylenimine (BPEI). The mechanical strength of the synthesized hydrogel displayed an increasing trend with the wt % of the cross-linker (BPEI) and achieved a maximum storage modulus (Gmax′) of 1093 Pa. Scanning electron microscopy revealed a porous network structure of the hydrogel (pore size: 30-70 μm), resulting in a very high swelling ratio of 5800%. The porous hydrogel manifested the maximum adsorption capacity of 482.2 mg/g when adsorbing from a mixture of metal ions (Cr3+, Cu2+, Zn2+, Cd2+, Hg2+, and Pb2+), higher than any EDTA-grafted material known to date. The high adsorption capacity of the hydrogel was attributed to the existence of numerous EDTA-mimicking coordinating functional groups, as confirmed by X-ray photoelectron spectroscopy. In addition, the hydrogel showed the self-healing property and preserved more than 85% adsorption efficiency even after five cycles of reuse. Furthermore, the hydrogels showed no or moderate toxicity toward mammalian cells.

Original languageEnglish (US)
Pages (from-to)25276-25285
Number of pages10
JournalACS Applied Materials and Interfaces
Volume12
Issue number22
DOIs
StatePublished - Jun 3 2020

Keywords

  • EDTA
  • Hydrogel
  • metal ion adsorbent
  • multidentate ligand
  • water purification

PubMed: MeSH publication types

  • Journal Article

Fingerprint Dive into the research topics of 'EDTA-Inspired Polydentate Hydrogels with Exceptionally High Heavy Metal Adsorption Capacity as Reusable Adsorbents for Wastewater Purification'. Together they form a unique fingerprint.

  • Cite this