TY - JOUR
T1 - Developing an efficient TiO2-coated biofilm carrier for intimate coupling of photocatalysis and biodegradation
AU - Li, Guozheng
AU - Park, Seongjun
AU - Rittmann, Bruce
N1 - Funding Information:
The study was supported by the US National Science Foundation (Grant No. 0651794 ). We sincerely thank Samsung Engineering Co. Ltd, Korea for kindly providing the sponge carriers. We also thank Dr. Zhenquan Liu for his help with the SEM imaging, David Lowry for his help with using critical point dryer, and Gaurav Albal for his help with photography.
PY - 2012/12/1
Y1 - 2012/12/1
N2 - Intimate coupling of photocatalysis and biodegradation (ICPB) shows promise to remove recalcitrant organic compounds from water, because photocatalysis breaks the compounds into biodegradable intermediates that are immediately mineralized by microorganisms inside a macroporous carrier, where they are protected from UV light and free radicals. Key to successful ICPB is a carrier capable of accumulating biofilm in its interior and strongly adhering photocatalyst on its exterior. We employed a low-temperature sintering method, the O method, to adhere TiO2 to sponge-type macroporous carriers. The O method achieved a 7-fold increase of TiO2 density, compared to the previously used sol-gel method, and it conserved the macropores for biofilm accumulation. Although the O-method carrier met the basic requirements of ICPB when degrading 2,4,5 trichlorophenol, it had low photocatalytic activity for breaking down more complex aromatics, like reactive dyes. Therefore, we improved the sintering method in two steps called the D and DN methods: reducing the TiO2 concentration and then removing trimesic acid in the coating solution. The photocatalytic efficiency towards reactive black 5 increased 5 fold for the D method and 10 fold for DN method, and the DN carrier had superior TiO2 adherence during long-term operation.
AB - Intimate coupling of photocatalysis and biodegradation (ICPB) shows promise to remove recalcitrant organic compounds from water, because photocatalysis breaks the compounds into biodegradable intermediates that are immediately mineralized by microorganisms inside a macroporous carrier, where they are protected from UV light and free radicals. Key to successful ICPB is a carrier capable of accumulating biofilm in its interior and strongly adhering photocatalyst on its exterior. We employed a low-temperature sintering method, the O method, to adhere TiO2 to sponge-type macroporous carriers. The O method achieved a 7-fold increase of TiO2 density, compared to the previously used sol-gel method, and it conserved the macropores for biofilm accumulation. Although the O-method carrier met the basic requirements of ICPB when degrading 2,4,5 trichlorophenol, it had low photocatalytic activity for breaking down more complex aromatics, like reactive dyes. Therefore, we improved the sintering method in two steps called the D and DN methods: reducing the TiO2 concentration and then removing trimesic acid in the coating solution. The photocatalytic efficiency towards reactive black 5 increased 5 fold for the D method and 10 fold for DN method, and the DN carrier had superior TiO2 adherence during long-term operation.
KW - Intimate coupling of photocatalysis and biodegradation
KW - Low-temperature sintering
KW - Sponge-type carrier
KW - Titanium dioxide
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U2 - 10.1016/j.watres.2012.09.029
DO - 10.1016/j.watres.2012.09.029
M3 - Article
C2 - 23062834
AN - SCOPUS:84868304178
SN - 0043-1354
VL - 46
SP - 6489
EP - 6496
JO - Water Research
JF - Water Research
IS - 19
ER -