What are the environmental benefits of nanofiltration for water treatment?

1 How nanofiltration works

Nanofiltration is a type of pressure-driven membrane separation process that can filter out molecules and ions with a size range of 1-10 nanometers. Nanofiltration membranes have pores that are smaller than those of ultrafiltration but larger than those of reverse osmosis. This allows nanofiltration to retain multivalent ions, organic compounds, and microorganisms, while allowing monovalent ions, water, and some dissolved gases to pass through.

2 Why nanofiltration is beneficial for the environment

Nanofiltration can offer several environmental benefits for water treatment, such as reducing energy consumption and greenhouse gas emissions while minimizing water loss and enhancing water recovery. Using nanofiltration can help recover energy from the concentrate stream by using pressure exchangers or turbines. Moreover, nanofiltration can improve water quality and protect public health by removing harmful contaminants and pollutants, as well as reducing the formation of disinfection by-products and the fouling of downstream processes. It can also recycle and reuse water for different purposes, such as irrigation, industrial processes, or potable water production.

3 How nanofiltration is applied in water treatment

Nanofiltration has many applications in water treatment, depending on the source water quality and the desired product water quality. For instance, nanofiltration can be used for wastewater treatment to remove organic matter, nutrients, color, and odor. Additionally, it can desalinate brackish water and seawater to produce fresh water for drinking or irrigation, as well as reduce the salinity and hardness of water to prevent scaling and corrosion. Moreover, nanofiltration can also be used for water reuse from various sources such as surface water, groundwater, rainwater, and stormwater. Furthermore, it can treat water for specific uses such as boiler feed water, cooling tower water, or ultrapure water.