Performance evaluation of carbon nanotube enhanced membranes for SWRO pretreatment application

• Multi-wall carbon nanotubes (MWCNTs) membrane was tested for seawater pretreatment.
• MWCNTs membrane showed a high permeate flux with organic reduction in seawater filtration.
• MWCNTs membrane can contribute to lessening the sludge volume in pretreatment.
• Ionic strength significantly affected organic removal efficiency in seawater filtration.

Multi-wall carbon nanotube (MWCNT) membrane was tested for SWRO pretreatment. The MWCNT membrane itself showed a superior permeate flux (321.3 LMH/bar), which was 4-times as polyethersulfone ultrafiltration (PES-UF) membrane. Reduction of dissolved organic matter improved to 66% with fewer amounts of powder activated carbon (PAC) (0.5 g/L) in MWCNT membrane filtration maintaining a high permeate flux of 600 LMH/bar. It was due to the increased porosity (84.5%) and hydrophilicity (52.9°) by incorporating MWCNT/polyaniline into PES membrane. Ionic strength affected organic removal in seawater filtration by altering electrostatic interaction between organic matter and surface charge of the positively charged MWCNT membrane.

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