Variations in backwash efficiency during colloidal filtration of hollow-fiber microfiltration membranes

Seungkwan Hong; Praveen Krishna; Colin Hobbs; Dohee Kim; Jaeweon Cho

doi:10.1016/j.desal.2004.07.049

Variations in backwash efficiency during colloidal filtration of hollow-fiber microfiltration membranes

Seungkwan Hong, Praveen Krishna, Colin Hobbs, Dohee Kim, Jaeweon Cho

School of Civil, Environmental and Architectural Engineering

Research output: Contribution to journal › Article › peer-review

32 Citations (Scopus)

Abstract

A series of filtration experiments was performed systematically to investigate physical and chemical factors affecting the efficiency of backwashing during microfiltration of colloidal suspensions. In this study, all experiments were conducted in dead-end filtration mode utilizing an outside-in, hollow-fiber module with a nominal pore size of 0.1 μm. Silica particles (mean diameter = 0.14 μm) were used as model colloids. Using a flux decline model based on the Happel's cell for the hydraulic resistance of the particle layer, the cake structure was determined from experimental fouling data and then correlated to backwash efficiency. Modeling of experimental data revealed no noticeable changes in cake layer structure when feed particle concentration and operating pressure increased. Specifically, the packing density of the cake layer (1-cake porosity) in the cake layer ranged from 0.66 to 0.67, which corresponds well to random packing density. However, the particle packing density increased drastically with ionic strength. The results of backwashing experiments demonstrated that the efficiency of backwashing decreased significantly with increasing solution ionic strength, while backwash efficiency did not vary when particle concentration and operating pressure increased. This finding suggests that backwash efficiency is closely related to the structure of the cake layer formed during particle filtration. More densely packed cake layers were formed under high ionic strength, and consequently less flux was recovered per given backwash volume during backwashing.

Original language	English
Pages (from-to)	257-268
Number of pages	12
Journal	Desalination
Volume	173
Issue number	3
DOIs	https://doi.org/10.1016/j.desal.2004.07.049
Publication status	Published - 2005 Mar 20

Keywords

Backwashing efficiency
Cake layer structure
Colloidal fouling
Microfiltration
Water treatment

ASJC Scopus subject areas

Chemistry(all)
Chemical Engineering(all)
Materials Science(all)
Water Science and Technology
Mechanical Engineering

Access to Document

10.1016/j.desal.2004.07.049

Cite this

@article{c430fbb127944cfcb9aa08be09ebf47d,

title = "Variations in backwash efficiency during colloidal filtration of hollow-fiber microfiltration membranes",

abstract = "A series of filtration experiments was performed systematically to investigate physical and chemical factors affecting the efficiency of backwashing during microfiltration of colloidal suspensions. In this study, all experiments were conducted in dead-end filtration mode utilizing an outside-in, hollow-fiber module with a nominal pore size of 0.1 μm. Silica particles (mean diameter = 0.14 μm) were used as model colloids. Using a flux decline model based on the Happel's cell for the hydraulic resistance of the particle layer, the cake structure was determined from experimental fouling data and then correlated to backwash efficiency. Modeling of experimental data revealed no noticeable changes in cake layer structure when feed particle concentration and operating pressure increased. Specifically, the packing density of the cake layer (1-cake porosity) in the cake layer ranged from 0.66 to 0.67, which corresponds well to random packing density. However, the particle packing density increased drastically with ionic strength. The results of backwashing experiments demonstrated that the efficiency of backwashing decreased significantly with increasing solution ionic strength, while backwash efficiency did not vary when particle concentration and operating pressure increased. This finding suggests that backwash efficiency is closely related to the structure of the cake layer formed during particle filtration. More densely packed cake layers were formed under high ionic strength, and consequently less flux was recovered per given backwash volume during backwashing.",

keywords = "Backwashing efficiency, Cake layer structure, Colloidal fouling, Microfiltration, Water treatment",

author = "Seungkwan Hong and Praveen Krishna and Colin Hobbs and Dohee Kim and Jaeweon Cho",

note = "Funding Information: The authors would like to acknowledge the American Water Works Association Research Foundation (AwwaRF) for financial support. Additional funding for this project was provided by Brain Korea 21 (BK21). Furthermore, SK Chemicals and Nissan Chemical Industries, Ltd., respectively provided the hollow-fiber MF module and model silica colloids used throughout this study.",

year = "2005",

month = mar,

day = "20",

doi = "10.1016/j.desal.2004.07.049",

language = "English",

volume = "173",

pages = "257--268",

journal = "Desalination",

issn = "0011-9164",

publisher = "Elsevier",

number = "3",

}

TY - JOUR

T1 - Variations in backwash efficiency during colloidal filtration of hollow-fiber microfiltration membranes

AU - Hong, Seungkwan

AU - Krishna, Praveen

AU - Hobbs, Colin

AU - Kim, Dohee

AU - Cho, Jaeweon

N1 - Funding Information: The authors would like to acknowledge the American Water Works Association Research Foundation (AwwaRF) for financial support. Additional funding for this project was provided by Brain Korea 21 (BK21). Furthermore, SK Chemicals and Nissan Chemical Industries, Ltd., respectively provided the hollow-fiber MF module and model silica colloids used throughout this study.

PY - 2005/3/20

Y1 - 2005/3/20

N2 - A series of filtration experiments was performed systematically to investigate physical and chemical factors affecting the efficiency of backwashing during microfiltration of colloidal suspensions. In this study, all experiments were conducted in dead-end filtration mode utilizing an outside-in, hollow-fiber module with a nominal pore size of 0.1 μm. Silica particles (mean diameter = 0.14 μm) were used as model colloids. Using a flux decline model based on the Happel's cell for the hydraulic resistance of the particle layer, the cake structure was determined from experimental fouling data and then correlated to backwash efficiency. Modeling of experimental data revealed no noticeable changes in cake layer structure when feed particle concentration and operating pressure increased. Specifically, the packing density of the cake layer (1-cake porosity) in the cake layer ranged from 0.66 to 0.67, which corresponds well to random packing density. However, the particle packing density increased drastically with ionic strength. The results of backwashing experiments demonstrated that the efficiency of backwashing decreased significantly with increasing solution ionic strength, while backwash efficiency did not vary when particle concentration and operating pressure increased. This finding suggests that backwash efficiency is closely related to the structure of the cake layer formed during particle filtration. More densely packed cake layers were formed under high ionic strength, and consequently less flux was recovered per given backwash volume during backwashing.

AB - A series of filtration experiments was performed systematically to investigate physical and chemical factors affecting the efficiency of backwashing during microfiltration of colloidal suspensions. In this study, all experiments were conducted in dead-end filtration mode utilizing an outside-in, hollow-fiber module with a nominal pore size of 0.1 μm. Silica particles (mean diameter = 0.14 μm) were used as model colloids. Using a flux decline model based on the Happel's cell for the hydraulic resistance of the particle layer, the cake structure was determined from experimental fouling data and then correlated to backwash efficiency. Modeling of experimental data revealed no noticeable changes in cake layer structure when feed particle concentration and operating pressure increased. Specifically, the packing density of the cake layer (1-cake porosity) in the cake layer ranged from 0.66 to 0.67, which corresponds well to random packing density. However, the particle packing density increased drastically with ionic strength. The results of backwashing experiments demonstrated that the efficiency of backwashing decreased significantly with increasing solution ionic strength, while backwash efficiency did not vary when particle concentration and operating pressure increased. This finding suggests that backwash efficiency is closely related to the structure of the cake layer formed during particle filtration. More densely packed cake layers were formed under high ionic strength, and consequently less flux was recovered per given backwash volume during backwashing.

KW - Backwashing efficiency

KW - Cake layer structure

KW - Colloidal fouling

KW - Microfiltration

KW - Water treatment

UR - http://www.scopus.com/inward/record.url?scp=18144386236&partnerID=8YFLogxK

U2 - 10.1016/j.desal.2004.07.049

DO - 10.1016/j.desal.2004.07.049

M3 - Article

AN - SCOPUS:18144386236

SN - 0011-9164

VL - 173

SP - 257

EP - 268

JO - Desalination

JF - Desalination

IS - 3

ER -

Variations in backwash efficiency during colloidal filtration of hollow-fiber microfiltration membranes

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this