skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Triplet Photochemistry of Effluent and Natural Organic Matter in Whole Water and Isolates from Effluent-Receiving Rivers
Award ID(s):
1132207
PAR ID:
10012554
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Environmental Science & Technology
Volume:
49
Issue:
6
ISSN:
0013-936X
Page Range / eLocation ID:
3453 to 3463
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. The increasing use of Gd-based contrast agents for magnetic resonance imaging at hospitals and research centers has led to the rapidly growing demand for Gd and Gd anomalies in surface waters. Recycling Gd from hospital effluents could simultaneously address Gd demand and severe concerns about Gd contamination. Here, we present a study relevant to the extraction and preconcentration of Gd from hospital effluents that contain parts per billion-level Gd via the ligand-assisted electrochemical aerosol formation (LEAF) process. We demonstrate that the LEAF process extracts ∼75% GdIII from 50 ppb Gd-spiked water samples, including diluted artificial urine samples while preconcentrating Gd by up to 390-fold. Mechanistic studies confirm that the surface activity of the Gd-binding ligand is essential for successful LEAF extraction. The ligands are recyclable by performing electrophoretic separation in an origami paper device, followed by water extraction. The steep pH gradient and strong electric field in the origami paper device enabled the dissociation of Gd-ligand complexes, spatial separation of Gd and ligand, and precipitation of GdIII as Gd(OH)3. Approximately 80% of the ligands were recovered from the paper device by water extraction and reused in subsequent extraction cycles. This straightforward and green method could also be adapted to other aqueous rare earth metal wastes in the future. 
    more » « less