Dynamic osmosis is demonstrated as an alternative water filtration system
Dynamic osmosis is demonstrated as an alternative water filtration system lead image
Lack of clean water and water scarcity are global issues that motivate constant innovation and development of water filtration systems. Traditional filtration methods, such as reverse osmosis, are limited by factors like energy consumption and the selectivity-permeability trade-off.
Marbach et al. study the concept of dynamic osmosis through active membranes to avoid the challenges associated with traditional filtration. They present a model demonstrating how water is transported through active membranes and record the properties of osmotic pressure as a function of the typical oscillating frequency.
“The idea of dynamic osmosis is then to use energy not to push water by a piston but to act directly on the membrane to open and close the membrane dynamically,” said author Lydéric Bocquet.
The authors’ research focuses on local pore size to induce a time-dependent, intermittent osmosis through the dynamic membranes. These membranes are made from porous materials whose interaction with the ions and fluid can be tuned or switched.
The process is energy efficient, because it moves salt atoms from one side to the other instead of moving huge amounts of water as reverse osmosis does.
“Nanofluidics have much to offer beyond the traditional sieving views, and one should harness the specific transport phenomena at the nanoscales. The dynamical osmosis that we highlight here provides such an example. This is a blank page and a virgin territory to explore,” said Bocquet.
The authors hope the information gained through their model will lead to new designs of devices that use active osmosis as filtration systems.
Source: “Resonant osmosis across active switchable membranes,” by Sophie Marbach, Nikita Kavokine, and Lydéric Bocquet, Journal of Chemical Physics (2020). The article can be accessed at https://doi.org/10.1063/1.5138987 .
