Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Use of ionic strength responsive polymeric microgels for fouling removal in membrane filtration
Download
index.pdf
Date
2019
Author
Çalılı, Fatma
Metadata
Show full item record
Item Usage Stats
364
views
115
downloads
Cite This
Stimuli-responsive polymeric surfaces can improve non-fouling properties of membranes and control their pore size and permeation characteristics upon alteration of stimulus intensity. In this study, zwitterionic poly(sulfobetaine methacrylate) (P(SBMA)) microgels have been added into the feed or deposited on the membrane surfaces to clean foulant deposits formed on the surface of the membranes after the filtration. Salt-responsive P(SBMA) microgels have altered their phase from swollen to shrunk, swollen to more swollen or shrunk to swollen due to the change of ionic strength in the medium. The effect of this size change in loosening and removing the fouling layer on the membrane was investigated. In the performance tests, PES (polyether sulfone) based ultrafiltration membranes were used. P(SBMA) microgels used in the tests as the ionic strength responsive microgel were synthesized by inverse emulsion free-radical polymerization. Fouling resistances and flux recoveries of membranes were calculated using pure water permeances (PWP) of neat membranes, filtration fluxes and PWP of the membranes after applying the cleaning procedure to compare their cleaning efficiencies. Different foulants, which are Bovine serum albumin (BSA), humic acid in the presence of calcium ions (HA gel) and yeast cells, were used with or without the zwitterionic microgels in the presence of different sodium chloride (NaCl) concentrations. To remove the cake layer, cleaning was performed via stirring and pure water/salt solution to make them shrink/swell. P(SBMA) microgels can maximally swell in the presence of 0.5 M NaCl. Due to the formation of highly adsorptive fouling, the microgels could not provide an efficient BSA fouling removal. HA gel fouling in the absence of NaCl was the most irreversible while when NaCl was in the feed, reversibility was similar with or without microgel. This possibly implies a looser cake layer in the presence of NaCl. Yeast fouling, however, was more reversible when P(SBMA) microgels were used, compared to fouling with yeast in pure water or in 0.5 M NaCl. In conclusion, this study showed how P(SBMA) microgels affect cake layer removal from PES UF membrane surface by adding them in the feed or depositing them on the membrane surface before the filtration. Presence of P(SBMA) microgels in the solution medium during the filtration could render higher flux recovery and cleaning efficiency than microgel-free filtrations for all foulants. Particularly, yeast fouling removal was achieved by adding of these microgels into the feed and depositing them on the membrane surface. These promising physical methods can be applicable to existing membrane processes to remove yeas-like foulants.
Subject Keywords
Membranes (Technology).
,
Separation (Technology).
,
Microgels.
,
Fouling.
URI
http://etd.lib.metu.edu.tr/upload/12623143/index.pdf
https://hdl.handle.net/11511/28068
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Responsive polymer particles for fouling removal during membrane filtrations
Aksoy, Canan; Çulfaz Emecen, Pınar Zeynep; Asatekin, Ayşe; Department of Chemical Engineering (2018)
In this study, temperature and ionic-strength responsive polymeric microgels are used for fouling removal in membrane filtrations by adding them into feed solutions such that they deposit on the membrane surface together with the foulants during filtration. For removal of the fouling layer, the microgels in collapsed form are brought into swollen phase or vice versa by applying temperature change. Recently, in literature, there are several studies that stimuli-responsive surfaces have been shown to be effec...
Investigation of parameters affecting morphology of microfiltration and ultrafiltration membranes fabricated via phase separation microfabrication
Bolat, Cankut Kaan; Çulfaz Emecen, Pınar Zeynep; Bat, Erhan; Department of Chemical Engineering (2017)
This study examines the factors affecting the morphology of polyethersulfone membranes produced via phase separation microfabrication technique. Flat and corrugated membranes were prepared using a combination of vapor induced and liquid induced phase separation, and characterized using scanning electron microscopy, pure water permeance tests and Baker’s yeast (Saccharomyces Cerevisiae) fouling tests. An inverse asymmetric morphology was tried to be achieved for corrugated membranes, in order to increase the...
Use of membrane bioreactors in treatment and re-use of domestic wastewaters
Komesli, Okan Tarık; Gökçay, Celal Ferdi; Department of Environmental Engineering (2006)
This study was carried out to investigate performance of a Vacuum Rotating Membrane (VRM) type membrane bioreactor (MBR). During the study, the VRM plant was erected from scratch and operated in METU campus. The plant was composed of two tanks. First one was about 100 m3 and it was used for biological treatment; the second tank, about 30 m3, was used as filter chamber. The permeate flow rate was adjusted between 6 and 8.5 m3/h giving a hydraulic retention time (HRT) of 18 hours during the study. In the aera...
Fabrication of helical polymeric hollow fiber membranes and characterization of their fouling behaviours
Yücel, Hazal; Çulfaz Emecen, Pınar Zeynep; Department of Chemical Engineering (2018)
Membranes are used in many separation processes such as gas separation, microfiltration, ultrafiltration and hemodialysis. Hollow fiber membranes are advantageous since they have a high surface area per volume and are easily backwashed which is an advantage for fouling removal. The most important factors that affect the performance of filtration membranes are concentration polarization and fouling. They increase operational cost and reduce membrane lifetime and permeate flux. One approach that can reduce co...
Investigation of phase inversion behavior of cellulose- ionic liquid solutions in relationship with membrane formation
Durmaz, Elif Nur; Çulfaz Emecen, Pınar Zeynep; Department of Chemical Engineering (2017)
Cellulose membranes were produced from ionic liquid solutions by phase inversion technique and thermodynamic and kinetic aspects of the process were investigated to relate these to membrane morphology and performance. In thermodynamics part, polymer-solvent, polymer-nonsolvent and polymer-solvent-nonsolvent interactions were examined experimentally, together with Hansen solubility parameter estimations. Kinetics part consisted of measuring phase inversion rate. Obtained membranes were characterized by their...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
F. Çalılı, “Use of ionic strength responsive polymeric microgels for fouling removal in membrane filtration,” M.S. - Master of Science, Middle East Technical University, 2019.