Nanofiltration technology in water treatment and reuse: applications and costs

Abstract

Nanofiltration (NF) is a relatively recent development in membrane technology with characteristics that fall between ultrafiltration and reverse osmosis (RO). While RO membranes dominate the seawater desalination industry, NF is employed in a variety of water and wastewater treatment and industrial applications for the selective removal of ions and organic substances, as well as certain niche seawater desalination applications. The purpose of this study was to review the application of NF membranes in the water and wastewater industry including water softening and color removal, industrial wastewater treatment, water reuse, and desalination. Basic economic analyses were also performed to compare the profitability of using NF membranes over alternative processes. Although any detailed cost estimation is hampered by some uncertainty (e.g. applicability of estimation methods to large-scale systems, labor costs in different areas of the world), NF was found to be a cost-effective technology for certain investigated applications. The selection of NF over other treatment technologies, however, is dependent on several factors including pretreatment requirements, influent water quality, treatment facility capacity, and treatment goals.

All cellulose electrospun water purification membranes nanotextured using cellulose nanocrystals

“…Water purification technology in food industry also faces some major technical barriers, especially while dealing with removal of small molecules and viruses and nanofiltration or reverse osmosis process is accompanied with high energy consumption and low water flux (Manth et al 2003;Shahmansouri and Bellona 2015). Ultrafiltration membranes systems can be a solution as they are typically more compact, require lower pressure than reverse osmosis or nanofiltration membrane systems, and also have the ability to remove harmful biologics while maintaining a relatively high flux, though the removal of smaller molecules and ions can still be challenging.…”

Rejection rate and mechanisms of drugs in drinking water by nanofiltration technology

“…Therefore, the study on the high-effective removal techniques of drugs from water is an urgent need. In recent decades, nanofiltration (NF), a low pressure-driven membrane process, has been gaining much attention due to its high rejection rates to many low molecule weight organic pollutants [12][13][14][15]. NF was a costly technology due to the short life cycle, easily fouling and high operation cost in the past.…”

“…NF was a costly technology due to the short life cycle, easily fouling and high operation cost in the past. However, with the development of research and the improved manufacturing technology, the cost of NF has decreased significantly, which makes NF become a promising application in water treatment [15][16][17][18][19]. For the quality and safety of supply drinking water, it is expected that NF will be widely employed into drinking water treatment in the near future.…”

Advanced treatment of municipal wastewater by nanofiltration: Operational optimization and membrane fouling analysis

“…It is well known that NF can effectively remove multivalent ions and high molecular weight organic compounds with lower operating pressure and higher permeate flux in comparison with RO. Thus, NF is a promising technology for advanced wastewater treatment considering its energy requirements and cost effectiveness, particularly when both NF and RO are suitable for wastewater reclamation (Alzahrani et al, 2013;Shahmansouri and Bellona, 2015). Despite these advantages, membrane fouling is still a key issue that hinders the application of membrane technologies.…”