A modeling investigation on optimizing the design of forward osmosis hollow fiber modules

Forward osmosis (FO) is an emerging osmotically driven membrane process, and its applications are becoming diversified. As one important membrane configuration, hollow fiber modules have been applied to some innovative FO processes, e.g., osmotic membrane bioreactor (OMBR). Aside from the inherent c...

Full description

Saved in:
Bibliographic Details
Main Authors: Xiao, Dezhong, Li, Weiyi, Chou, Shuren, Wang, Rong, Tang, Chuyang Y.
Other Authors: School of Civil and Environmental Engineering
Format: Article
Language:English
Published: 2013
Subjects:
Online Access:https://hdl.handle.net/10356/100381
http://hdl.handle.net/10220/13623
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Nanyang Technological University
Language: English
Description
Summary:Forward osmosis (FO) is an emerging osmotically driven membrane process, and its applications are becoming diversified. As one important membrane configuration, hollow fiber modules have been applied to some innovative FO processes, e.g., osmotic membrane bioreactor (OMBR). Aside from the inherent concentration polarization (CP) phenomena, new challenges are posed by the coupled concentrating and dilution effects in the design of FO hollow fiber modules. In this paper, a mathematical model is therefore developed to account for the evolution of the local performances within the FO hollow fiber module and to evaluate the global performances of interest. Then, this model is employed to theoretically investigate the filtration behaviors of the FO hollow fiber module by using the well-defined dimensionless groups, which indicates the complex interplay among a variety of design parameters. Particularly, the optimization objectives are focused on enhancing the module-averaged FO efficiency and avoiding the severe concentration variations in the module channels. In terms of the simulation results, some criteria are obtained for optimizing the operating conditions (flow configuration, inlet concentration level, inlet flow rate), the hollow fiber characteristics (fiber length), and the FO membrane properties (active layer selectivity, support layer transport resistance). This work provides deep insights into the design of the FO hollow fiber module, and could be readily modified to accommodate more complicated cases.