Effects of mass retention of dissolved organic matter and membrane pore size on membrane fouling and flux decline

• Published in: Water research (Oxford) Vol. 43; no. 2; pp. 389 - 394
• Main Authors: Lin, Cheng-Fang, Yu-Chen Lin, Angela, Sri Chandana, Panchangam, Tsai, Chao-Yuan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-02-2009; Elsevier
• Subjects: Applied sciences; artificial membranes; Bioreactors; dissolved organic carbon; dissolved organic matter; Dissolved organic matter (DOM); DOM retention; equipment design; equipment performance; Exact sciences and technology; humic acids; Membrane fouling; Membrane resistance; Membranes, Artificial; Other industrial wastes. Sewage sludge; Pollution; Ultrafiltration; Ultrafiltration - instrumentation; Waste Disposal, Fluid - instrumentation; Waste Disposal, Fluid - methods; Wastes; wastewater treatment; water treatment; Water treatment and pollution; DOM retention; Membrane resistance; Dissolved organic matter (DOM); Ultrafiltration; Membrane fouling; Organic matter; Fouling; Filtration; Water supply; Permeability; Dissolved matter; Dissolved organic carbon; Membrane separation; Pore size; Biofouling; Biofilm; Waste water purification
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2008.10.042

Ultrafiltration (UF) fouling has been attributed to concentration polarization, gel layer formation as well as outer and inner membrane pore clogging. It is believed that mass of humic materials either retained on membrane surface or associated with membrane inner pore surface is the primary cause for permeate flux decline and filtration resistance build-up in water supply industries. While biofilm/biofouling and inorganic matter could also be contributing factors for permeability decline in wastewater treatment practices. The present study relates UF fouling to mass of dissolved organic matter (DOM) retained on membrane and quantifies the effect of retained DOM mass on filtration flux decline. The results demonstrate that larger pore membranes exhibit significant flux decline in comparison with the smaller ones. During a 24-h period, dissolved organic carbon mass retained in 10
kDa membranes was about 1.0
g
m
−2 and that in 100
kDa membranes was more than 3 times higher (3.6
g
m
−2). The accumulation of retained DOM mass significantly affects permeate flux. It is highly likely that some DOMs bind or aggregate together to form surface gel layer in the smaller 10
kDa UF system; those DOMs largely present in inner pore and serving as pore blockage on a loose membrane (100
kDa) are responsible for severe flux decline.