Dendrimer-Enhanced Filtration: Principles and Applications to Water Treatment and Desalination
Speaker : Mamadou S. Diallo, Ph.D.
Date & Time : 2009. 6. 3 (Wed), 14:00
Place : 신소재공학과 #2427강의실
Abstract
Pressure-driven membrane processes such reverse osmosis (RO), nanofiltrafiltration (NF), ultrafiltration (UF) and microfiltration (MF) are emerging as key components of water treatment and desalination systems throughout the world. The bulk of the capital and operating costs of membrane systems is associated with the high pressure needed to remove dissolved contaminants (e.g., monovalent ions and small organic molecules). RO and NF are very effective at removing dissolved ions. However, high pressures (7-70 bar) are required to operate NF and RO membranes. Conversely, UF and MF membranes require much lower pressure (0.3-2 bar). Unfortunately, they are not effective at retaining dissolved ions. We have developed a dendrimer enhanced filtration (DEF) process that can remove dissolved ions using UF and MF membrane systems. Dendritic macromolecules, which include dendrimers, hyperbranched polymers and dendrigraft polymers, are highly branched 3D globular polymers with controlled composition and architecture. They have many reactive functional sites and binding pockets per molecule, and their globular shape and large size make them easier to filter than linear polymers. DEF works by combining dendritic macromolecules with conventional UF or MF membrane systems. Functionalized dendritic macromolecules are added to an incoming aqueous solution and bind with the target contaminants. For most dissolved solutes (e.g., cations and anions), a change in solution acidity and/or salinity causes the dendritic macromolecules to bind or release the target ions. Thus, a two-stage filtration process can be used to recover and concentrate a variety of dissolved ions in water. This concentrated solution is then collected for disposal or subsequent processing while the dendritic macromolecules are recycled.
In this presentation, I will discuss the principles and applications of DEF to water treatment. Examples that will be discussed include the recovery of toxic metal ions (e.g., copper, silver and uranium) from industrial wastewater and the removal of anions (e.g. perchlorate, nitrate and bromide) from groundwater. I will also highlight my vision for using dendritic macromolecules as functional materials to develop the next generation of low-pressure filtration systems for brackish water and seawater desalination.
Speaker : Mamadou S. Diallo, Ph.D.
Date & Time : 2009. 6. 3 (Wed), 14:00
Place : 신소재공학과 #2427강의실
Abstract
Pressure-driven membrane processes such reverse osmosis (RO), nanofiltrafiltration (NF), ultrafiltration (UF) and microfiltration (MF) are emerging as key components of water treatment and desalination systems throughout the world. The bulk of the capital and operating costs of membrane systems is associated with the high pressure needed to remove dissolved contaminants (e.g., monovalent ions and small organic molecules). RO and NF are very effective at removing dissolved ions. However, high pressures (7-70 bar) are required to operate NF and RO membranes. Conversely, UF and MF membranes require much lower pressure (0.3-2 bar). Unfortunately, they are not effective at retaining dissolved ions. We have developed a dendrimer enhanced filtration (DEF) process that can remove dissolved ions using UF and MF membrane systems. Dendritic macromolecules, which include dendrimers, hyperbranched polymers and dendrigraft polymers, are highly branched 3D globular polymers with controlled composition and architecture. They have many reactive functional sites and binding pockets per molecule, and their globular shape and large size make them easier to filter than linear polymers. DEF works by combining dendritic macromolecules with conventional UF or MF membrane systems. Functionalized dendritic macromolecules are added to an incoming aqueous solution and bind with the target contaminants. For most dissolved solutes (e.g., cations and anions), a change in solution acidity and/or salinity causes the dendritic macromolecules to bind or release the target ions. Thus, a two-stage filtration process can be used to recover and concentrate a variety of dissolved ions in water. This concentrated solution is then collected for disposal or subsequent processing while the dendritic macromolecules are recycled.
In this presentation, I will discuss the principles and applications of DEF to water treatment. Examples that will be discussed include the recovery of toxic metal ions (e.g., copper, silver and uranium) from industrial wastewater and the removal of anions (e.g. perchlorate, nitrate and bromide) from groundwater. I will also highlight my vision for using dendritic macromolecules as functional materials to develop the next generation of low-pressure filtration systems for brackish water and seawater desalination.
