**Author details**

*Water Quality - Science, Assessments and Policy*

**7. Summary**

**Acknowledgements**

**Conflict of interest**

University, CREST Award #1036593.

The authors declare no conflict of interest.

advantages of low membrane fouling, feasibility to treat high salinity water, possibility to run at low voltage electricity, and applications in osmotic dilution at low energy demand. When thermal volatile draw solute is used, FO can easily be integrated with low-grade heat, such as waste heat in a power plant and thermal heat gathered by highly efficient solar collector, for draw solute recovery [57, 58]. MD as a thermal membrane separation process has the nature to utilize low-grade heat easily, and it also possesses distinctive advantages of low membrane fouling and low operation energy demand of heating the feed and cooling the permeate when integrating with low-grade heat source and high quality of product water when using VMD and AGMD in the desalination of highly saline water [59]. The utilization of PEG, its derivatives, and copolymers in FO and MD membranes can improve the overall membrane performance, thus enhancing the abilities of these membranes in various applications. **Table 1** summarizes the performance of PEG-assisted FO and

PEG, its derivatives, and copolymers are water soluble depending on their molecular weights, terminal, and copolymer blocks. They have widely been utilized in membrane fabrications and performance tests of some membranes due to the nature of hydrophilicity of these polymers. This chapter focuses on PEG applications in two emerging membrane technologies FO and MD. With regard to FO, PEG can not only be integrated into some draw solutes for easy draw solute recovery but can also be applied to the support and active layers for improving membrane antifouling properties. On the other hand, PEG is mainly used as pore-forming additive in the MD membrane fabrication. Compared to the control membranes in the various studies which are summarized here, PEG-assisted FO and MD membranes exhibit better overall performance for wastewater treatment and desalination according to water flux, flux recovery after cleaning, and antifouling behaviors.

This work is supported by the National Science Foundation (NSF) through the Center for Energy and Environmental Sustainability (CEES) at Prairie View A&M

MD membranes used in wastewater treatment and desalination.

**64**

Hongbo Du1 , Subhani Bandara2 , Laura E. Carson<sup>2</sup> and Raghava R. Kommalapati3 \*

1 Center for Energy and Environmental Sustainability, Prairie View A&M University, Prairie View, Texas, USA

2 Cooperative Agricultural Research Center, Prairie View A&M University, Prairie View, Texas, USA

3 Department of Civil and Environmental Engineering, Center for Energy and Environmental Sustainability, Prairie View A&M University, Prairie View, Texas, USA

\*Address all correspondence to: rrkommalapati@pvamu.edu

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
