Using UCST Ionic Liquid as a Draw Solute in Forward Osmosis to Treat High-Salinity Water

The concept of using a thermoresponsive ionic liquid (IL) with an upper critical solution temperature (UCST) as a draw solute in forward osmosis (FO) was successfully demonstrated here experimentally. A 3.2 M solution of protonated betaine bis­(trifluoromethylsulfonyl)­imide ([Hbet]­[Tf2N]) was obta...

Full description

Saved in:
Bibliographic Details
Published in:Environmental science & technology 2016-01, Vol.50 (2), p.1039-1045
Main Authors: Zhong, Yujiang, Feng, Xiaoshuang, Chen, Wei, Wang, Xinbo, Huang, Kuo-Wei, Gnanou, Yves, Lai, Zhiping
Format: Article
Language:English
Subjects:
Heating
Ionic Liquids - chemistry
Ions
Osmosis
Salinity
Solubility
Solutions - chemistry
Spectrophotometry, Ultraviolet
Temperature
Temperature effects
Ultraviolet radiation
Water - chemistry
Water Purification - methods
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The concept of using a thermoresponsive ionic liquid (IL) with an upper critical solution temperature (UCST) as a draw solute in forward osmosis (FO) was successfully demonstrated here experimentally. A 3.2 M solution of protonated betaine bis­(trifluoromethylsulfonyl)­imide ([Hbet]­[Tf2N]) was obtained by heating and maintaining the temperature above 56 °C. This solution successfully drew water from high-salinity water up to 3.0 M through FO. When the IL solution cooled to room temperature, it spontaneously separated into a water-rich phase and an IL-rich phase: the water-rich phase was the produced water that contained a low IL concentration, and the IL-rich phase could be used directly as the draw solution in the next cycle of the FO process. The thermal stability, thermal-responsive solubility, and UV–vis absorption spectra of the IL were also studied in detail.
ISSN:0013-936X
1520-5851
DOI:10.1021/acs.est.5b03747