TY - JOUR
T1 - Ozone membrane contactors for water and wastewater treatment
T2 - A critical review on materials selection, mass transfer and process design
AU - Bein, Emil
AU - Zucker, Ines
AU - Drewes, Jörg E.
AU - Hübner, Uwe
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/6/1
Y1 - 2021/6/1
N2 - Gas-liquid membrane contactors are frequently proposed as promising alternative for traditional ozone injection methods in water treatment. However, information on successfully implemented large-scale applications is scarce. This review discusses the state of research of ozone membrane contactors for water and wastewater applications with a focus on material stability, mass transfer performance and process design. It aims to identify favorable operating conditions, the benefits compared to traditional injection methods and critical aspects for upscaling. Reported experimental ozone mass transfer coefficients (K) in hollow fiber and single tube contactors were analyzed for relevant influential parameters and compared to calculations using the Lévêque solution and the Kreulen modification. Volumetric mass transfer coefficients (Kas) were used for comparison with other ozone delivery methods. Differences between experimental and calculated mass transfer coefficients increased towards lower mass transfer and liquid velocity, potentially due to enhanced membrane resistances and ozone decay. The highest mass transfer coefficients were found for hydrophobic polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE) membranes, while polydimethylsiloxane (PDMS), hydrophilic PVDF, and inorganic membranes showed lower transfer efficiencies. Although mass transfer enhancement by fast ozone depletion in the liquid bulk and in the boundary layer can be significant during water treatment, this design-factor is mostly neglected for ozone membrane contactors examined in the peer-reviewed literature. PVDF and PTFE hollow fiber modules exhibit higher volumetric mass transfer coefficients compared to traditional injection methods including bubble columns and venturi injectors, but full-scale and economic studies are missing to assess potential benefits of this new ozone injection method. In addition, long-term material stability is uncertain for most materials. Overall, this study provides a comprehensive comparison of gas–liquid contactors, suggesting future areas of research.
AB - Gas-liquid membrane contactors are frequently proposed as promising alternative for traditional ozone injection methods in water treatment. However, information on successfully implemented large-scale applications is scarce. This review discusses the state of research of ozone membrane contactors for water and wastewater applications with a focus on material stability, mass transfer performance and process design. It aims to identify favorable operating conditions, the benefits compared to traditional injection methods and critical aspects for upscaling. Reported experimental ozone mass transfer coefficients (K) in hollow fiber and single tube contactors were analyzed for relevant influential parameters and compared to calculations using the Lévêque solution and the Kreulen modification. Volumetric mass transfer coefficients (Kas) were used for comparison with other ozone delivery methods. Differences between experimental and calculated mass transfer coefficients increased towards lower mass transfer and liquid velocity, potentially due to enhanced membrane resistances and ozone decay. The highest mass transfer coefficients were found for hydrophobic polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE) membranes, while polydimethylsiloxane (PDMS), hydrophilic PVDF, and inorganic membranes showed lower transfer efficiencies. Although mass transfer enhancement by fast ozone depletion in the liquid bulk and in the boundary layer can be significant during water treatment, this design-factor is mostly neglected for ozone membrane contactors examined in the peer-reviewed literature. PVDF and PTFE hollow fiber modules exhibit higher volumetric mass transfer coefficients compared to traditional injection methods including bubble columns and venturi injectors, but full-scale and economic studies are missing to assess potential benefits of this new ozone injection method. In addition, long-term material stability is uncertain for most materials. Overall, this study provides a comprehensive comparison of gas–liquid contactors, suggesting future areas of research.
KW - Advanced oxidation processes
KW - Gas–liquid membrane contactor
KW - Mass transfer
KW - Ozonation
KW - Water treatment
UR - http://www.scopus.com/inward/record.url?scp=85096402252&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2020.127393
DO - 10.1016/j.cej.2020.127393
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AN - SCOPUS:85096402252
SN - 1385-8947
VL - 413
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 127393
ER -