Membrane-based seawater desalination: Present and future prospects

TLDR: In this article, the state-of-the-art in present seawater desalination practice, emphasizing membrane-based technologies, was explored, while identifying future opportunities in step improvements to conventional technologies and development of emerging, potentially disruptive, technologies through advances in material science, process engineering, and system integration.

About: This article is published in Desalination.The article was published on 2017-01-02 and is currently open access. It has received 487 citations till now. The article focuses on the topics: Desalination & Geothermal desalination.

Frequently asked questions

Q1. What are the contributions in "Membrane-based seawater desalination: present and future prospects" ?

This paper explores the state-of-the-art in present seawater desalination practice, emphasizing membrane-based technologies, while identifying future opportunities in step improvements to conventional technologies and development of emerging, potentially disruptive, technologies through advances in material science, process engineering, and system integration. In this paper, seawater reverse osmosis ( RO ) serves as the baseline conventional technology. The discussion extends beyond desalting processes into membrane-based salinity gradient energy production processes, which can provide an energy offset to desalination process energy requirements. The future membrane landscape in membrane-based desalination and salinity gradient energy is projected to include ultrahigh permeability RO membranes, renewable-energy driven desalination, and emerging processes including closed-circuit RO, membrane distillation, forward osmosis, pressure retarded osmosis, and reverse electrodialysis according various niche applications and/or hybrids, operating separately or in conjunction with RO. 

Q2. What is the common type of membrane?

Synthetic ion channel membranes, depending on the specific channel, may function as either ion exchange membranes for cations or anions, or as a molecular gate for all ions. 

Q3. What is the common term used in the sentence?

While (fossil fuel) reductions will lead to a concomitant reduction in GHG emissions, further reductions can be realized by solardriven SWRO and, for off-the-grid applications, solar MD. 

Q4. What is the important term for the passage?

Future seawater desalination technology adoption should be based on a rigorous life cycle assessment (LCA) that goes beyond unit costs ($/m3) and also takes into account environmental impact minimization. 

Q5. What are the main topics of the paper?

Brine ConcentrationFO-LPRO, FO-MDTreatment, Brine ConcentrationFO-MD, MD-PRO, MD-RED8.0 Path Forward for Reducing Specific Energy Consumption and GHG EmissionsFane et al. (2015) state that improvements are necessary in membranes, modules, and processes (i.e., membrane engineering). 

Q6. What is the important topic in the paper?

Two interesting opportunities are: (i) membranes incorporating synthetic ion channels and (ii) further evolution of CDI in transitioning from a brackish to a seawater technology in concert with materials-improvements in highercapacity electrodes and further process intensification to membrane-CDI (M-CDI). 

Q7. What is the common term used to describe the CC-RO process?

In the near-term, CC-RO is now emerging into the commercial arena as well as FO and MD in niche applications; however, improved-performance hollow-fiber FO and MD membranes will allow other, potentially more efficient FO and MD process configurations (versus commercially-available flat-sheet membranes). 

Q8. What is the main focus of the paper?

Given the relatively lower energy requirement of SWRO pre- and post-treatment (< 0.5 kWh/m3), their major focus is on the SWRO membrane process itself (> 2.5 kWh/m3) in terms of UHP RO membranes or emerging processes. 

Q9. What is the impact of the SWRO brine disposal process on the environment?

In addition, more stringent SWRO brine disposal requirements may lead to further energy investment in multi-port diffuser systems in order to achieve a restricted mixing zone. 

Q10. What is the role of the SWRO pretreatment process in the development of a sustainable water?

Given the recent interest in subsurface intakes, a careful energetic and environmental analysis is needed in comparison to open intakes, however, it is important to acknowledge that subsurface intakes may in themselves play the role of the SWRO pre-treatment process whereas open intakes require a separate pretreatment process with its own energy requirements.