Superabsorbent Polymers for the Development of Nanofiltration

Numerous types of membranes having pores sizes within the range of 1 to 10 nm have been employed for nanofiltration. Materials commonly employed as membranes for nanofiltration consist of polyethylene terephthalate or metallic materials such as aluminum. Superabsorbent polymers (SAPs) are gradually gaining popularity in the field of nanofiltration. SAPs are polymeric materials having hydrophilic networks which have the potential of retaining large amounts of aqueous solution or water up to a thousand times their own weight. These materials have found relevance in various sectors such as agriculture, pharmaceuticals, health and numerous commercial applications. They have also been employed as soil conditioners for the purpose of storing ground water, retaining and discharging plants nutrients, and general improvement of soil. More recently SAPs have also found relevance in hazardous wastewater treatment processes such as nanofiltration. Nanofiltration is a membrane based filtration process that is pressure driven and employed commonly for the treatment of wastewater. This chapter discusses the application of superabsorbent polymers for nanofiltration. It highlights the preparations of SAPs, their physicochemical properties that make them suitable for nanofiltration, unique advantages in their application in nanofiltration, and the challenges in the use of SAPs in nanofiltration. Finally, some recent studies on the use of SAPs in the area of nanofiltration are also presented.