Abstract

Forward osmosis (FO) and membrane distillation (MD) are two emerging membrane technologies, and both have advantages of low membrane fouling, ability to use for highly saline desalination, and feasibility to integrate with a low-grade heat source like solar collector. Because polyethylene glycol (PEG) is a flexible, water-soluble polymer, it is an essential material used for membrane fabrication and enhancement of membrane properties. Low-molecular-weight PEG sometimes is used as pore constrictor and pore former for developing MD membranes and support layer of FO membranes. Due to the affinity of PEG chains to water molecules, PEG, its derivatives, and copolymers have been widely used in the fabrication/modification of FO and MD membranes, which are currently applied to bioseparation, wastewater treatment, and desalination in academia and industry at the pilot scale. This chapter covers direct PEG and its membrane separation applications in wastewater treatment and desalination. The advancement of PEG in membrane science and engineering is reviewed and discussed comprehensively. We focus on the effectiveness of PEG on membrane antifouling and the stability of PEG-modified membranes when applied to wastewater treatment and desalination.

Highlights

  • polyethylene glycol (PEG) is available as linear or branched chain polymers with terminal hydroxyl groups

  • Ge et al have synthesized supramagnetic nanoparticles to be used as draw solutes in forward osmosis (FO) membrane using polyethylene glycol activated with two carboxylic acid groups at the terminal ends [8]

  • PEG succinimidyl succinate (PEG-SS) produced by reacting Monomethoxy PEG (mPEG) with succinic anhydride followed by carboxylic acid activation to form succinimidyl ester is an NHS ester that has been successfully coupled to the enzyme asparaginase [4, 9]

Read more

Summary

Hetero- and homobifunctional PEG derivatives

Various hetero- and homobifunctional products of PEG can be synthesized by different methods. Bentley et al have shown a method to synthesize heterobifunctional PEG derivatives in high purity and high yield, by going through an intermediate with an removable group [5]. They have first attached a benzyloxy group as the removable group to one end of PEG. After modifying the other terminal OH group with a required molecule, the first group was removed by hydrogenolysis or hydrolysis Afterward, another functional group can be attached to the newly available OH group, or the new OH can be converted to a different functional group.

Monofunctional PEG derivatives
Principle of forward osmosis
Principle of membrane distillation
PEG used as/in draw solute
PEG in the support layer of an FO membrane
PEG in the active layer of an FO membrane
PEG used as pore-forming additive
PEG applied to surface modification of MD membrane
PEG-assisted membranes in wastewater treatment and desalination
Findings
Summary
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.