Environmental Engineering Reference
In-Depth Information
27
Water Desalination: Emerging and
Existing T
echnologies
Shaurya Prakash,
1
Mark A. Shannon,
2
and Karen Bellman
1
1
Department of Mechanical and Aerospace Engineering,
The Ohio State University, Columbus, Ohio, USA
2
Department of Mechanical Science and Engineering, University of
Illinois at Urbana-Champaign, Urbana, Illinois, USA
CONTENTS
27.1 Introduction ........................................................................................................................ 533
27.2 Review of Existing Water Desalination Methods ......................................................... 536
27.2.1 Theoretical Minimum Energy Requirement for Water Desalination ............ 536
27.2.2 Challenges to Desalination Processes ................................................................ 537
27.2.3 Common Separation Methods ............................................................................. 537
27.2.3.1 MSF Distillation ...................................................................................... 539
27.2.3.2 Multi-Effect Distillation ......................................................................... 539
27.2.3.3 Vapor Compression (VC) Processes ..................................................... 540
27.2.3.4 Reverse Osmosis...................................................................................... 541
27.2.3.5 Electrodialysis and Electrodialysis Reversal ......................................544
27.2.3.6 Challenges with Membrane Processes ................................................ 546
27.3 Emerging Water Desalination Technologies.................................................................. 549
27.3.1 Forward Osmosis ................................................................................................... 550
27.3.2 Microluidic and Nanoluidic Concentration Polarization for Desalination ... 551
27.3.3 Advanced Membranes .......................................................................................... 552
27.3.4 Humidiication-Dehumidiication Desalination .............................................. 554
27.3.5 Microbial Desalination Cells ................................................................................ 555
27.3.6 Asymmetry-Driven Ion Pumps ........................................................................... 556
27.4 Summary and Conclusions .............................................................................................. 557
References ..................................................................................................................................... 557
27.1 Introduction
The ability to procure or produce clean water is essential for health, energy, and security
demands [1-4]. The following statistics on water quality effects emphasize the importance
of advancing the science and technology to increase freshwater supplies. On the basis
of World Health Organization (WHO) reports, nearly 2.4 million people die every year
533
