Quantifying osmotic membrane fouling to enable comparisons across diverse processes
Name
Structural_parameter_2015.pdf
Size
721.53 KB
Format
Adobe PDF
Checksum (MD5)
1b1aa580dc289c996cfe8780d2d372b3
Author(s)
Tow, Emily W.
Lienhard, John H
Date Issued
March 2016
Journal
Journal of Membrane Science
Publisher
Elsevier
Citation
Tow, Emily W., and John H. Lienhard V. “Quantifying Osmotic Membrane Fouling to Enable Comparisons across Diverse Processes.” Journal of Membrane Science 511 (August 2016): 92–107.
Version
Author's final manuscript
Abstract
In this study, a method of in situ membrane fouling quantification is developed that enables comparisons of foulant accumulation between desalination processes with different membranes, driving forces, and feed solutions. Unlike the conventional metric of flux decline, which measures the response of a process to fouling, the proposed method quantifies the foulant accumulation. Foulant accumulation is parameterized by two variables, cake structural parameter and hydraulic diameter, that are calculated from flux measurements using a model for salt and water transport through fouled reverse osmosis (RO) and forward osmosis (FO) membranes, including dispersive mass transfer in the FO membrane support layer. Model results show that pressure declines through the foulant layer and can, in FO, reach negative absolute values at the membrane. Experimental alginate gel fouling rates are measured within a range of feed ionic compositions where cake hydraulic resistance is negligible. Using both flux decline and cake structural parameter as metrics, the effect of feed salinity on RO fouling is tested and RO is compared to FO. When RO is fouled with alginate, feed salinity and membrane permeability affect flux decline but not foulant accumulation rate. Between FO and RO, the initial rates of foulant accumulation are similar; however, FO exhibits slower flux decline, which causes greater foulant accumulation over time. The new methodology enables meaningful quantification and comparison of fouling rates with the aim of improving fundamental understanding of fouling processes.
MIT Department
Massachusetts Institute of Technology. Abdul Latif Jameel World Water & Food Security Lab
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.memsci.2016.03.040
