摘要
A flat submerged membrane combined with a TiO 2 /UV photocatalytic reactor (FSMPR) was employed in batch mode to remove humic acid (HA). HA removal efficiency was characterized by UV 254 absorbance, UV-vis spectra, dissolved organic carbon (DOC) concentration, specific UV absorbance (SUVA), and trihalomethane formation potential (THMFP). The FSMPR process was effective in removing more than 86% of DOC and nearly 100% of UV 254 absorbance, while the THMFPs of samples were reduced to < 19 μ g/L after 150 min of treatment. In addition, changes in transmembrane pressure (TMP) with and without UV were evaluated; TiO 2 /UV was effective at controlling membrane fouling by HA. Analysis of the molecular weight (MW) distributions and three-dimensional excitation-emission matrix (EEM) fluorescence spectra of HAs revealed that the effectiveness in membrane fouling control is a result of changes in HA molecular characteristics. The TiO 2 /UV photocatalytic reactor caused the degradation of high MW, hydrophobic humic-like molecules to low MW, hydrophilic protein-like molecules, although this fraction was not completely removed during 150 min of treatment and was less responsible for membrane fouling.
A flat submerged membrane combined with a TiO2/UV photocatalytic reactor （FSMPR） was employed in batch mode to remove humic acid （HA）. HA removal efficiency was characterized by UV254 absorbance, UV-vis spectra, dissolved organic carbon （DOC） concentration, specific UV absorbance （SUVA）, and trihalomethane formation potential （THMFP）. The FSMPR process was effective in removing more than 86% of DOC and nearly 100% of UV254 absorbance, while the THMFPs of samples were re- duced to 〈 19 tag/L after 150 rain of treatment. In addition, changes in transmembrane pressure （TMP） with and without UV were evaluated; TiO2/UV was effective at controlling membrane fouling by HA. Analysis of the molecular weight （MW） distributions and three-dimensional excitation-emission matrix （EEM） fluorescence spectra of HAs revealed that the effectiveness in membrane fouling control is a result of changes in HA molecular characteristics. The TiOffUV photocatalytic reactor caused the degradation of high MW, hydrophobic humic-like molecules to low MW, hydrophilic protein-like molecules, although this fraction was not completely removed during 150 rain of treatment and was less responsible for membrane fouling.
基金
supported by the National Water Pollution Control and Treatment Key Technologies R&D Program (2008ZX07421-006 and 2009ZX 07424-006)
