Enzymatic cleaning of biofouled thin-film composite reverse osmosis (RO) membrane operated in a biofilm membrane reactor
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Enzymatic cleaning of biofouled thin-film composite reverse osmosis (RO) membrane operated in a biofilm membrane reactor. / Khan, Mohiuddin; Danielsen, Steffen; Johansen, Katja; Lorenz, Lindsey; Nelson, Sara; Camper, Anne.
In: Biofouling, Vol. 30, No. 2, 02.2014, p. 153-167.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Enzymatic cleaning of biofouled thin-film composite reverse osmosis (RO) membrane operated in a biofilm membrane reactor
AU - Khan, Mohiuddin
AU - Danielsen, Steffen
AU - Johansen, Katja
AU - Lorenz, Lindsey
AU - Nelson, Sara
AU - Camper, Anne
PY - 2014/2
Y1 - 2014/2
N2 - Application of environmentally friendly enzymes to remove thin-film composite (TFC) reverse osmosis (RO) membrane biofoulants without changing the physico-chemical properties of the RO surface is a challenging and new concept. Eight enzymes from Novozyme A/S were tested using a commercially available biofouling-resistant TFC polyamide RO membrane (BW30, FilmTech Corporation, Dow Chemical Co.) without filtration in a rotating disk reactor system operated for 58 days. At the end of the operation, the accumulated biofoulants on the TFC RO surfaces were treated with the three best enzymes, Subtilisin protease and lipase; dextranase; and polygalacturonase (PG) based enzymes, at neutral pH (~7) and doses of 50, 100, and 150 ppm. Contact times were 18 and 36 h. Live/dead staining, epifluorescence microscopy measurements, and 5 μm thick cryo-sections of enzyme and physically treated biofouled membranes revealed that Subtilisin protease- and lipase-based enzymes at 100 ppm and 18 h contact time were optimal for removing most of the cells and proteins from the RO surface. Culturable cells inside the biofilm declined by more than five logs even at the lower dose (50 ppm) and shorter incubation period (18 h). Subtilisin protease- and lipase-based enzyme cleaning at 100 ppm and for 18 h contact time restored the hydrophobicity of the TFC RO surface to its virgin condition while physical cleaning alone resulted in a 50° increase in hydrophobicity. Moreover, at this optimum working condition, the Subtilisin protease- and lipase-based enzyme treatment of biofouled RO surface also restored the surface roughness measured with atomic force microscopy and the mass percentage of the chemical compositions on the TFC surface estimated with X-ray photoelectron spectroscopy to its virgin condition. This novel study will encourage the further development and application of enzymes to remove biofoulants on the RO surface without changing its surface properties.
AB - Application of environmentally friendly enzymes to remove thin-film composite (TFC) reverse osmosis (RO) membrane biofoulants without changing the physico-chemical properties of the RO surface is a challenging and new concept. Eight enzymes from Novozyme A/S were tested using a commercially available biofouling-resistant TFC polyamide RO membrane (BW30, FilmTech Corporation, Dow Chemical Co.) without filtration in a rotating disk reactor system operated for 58 days. At the end of the operation, the accumulated biofoulants on the TFC RO surfaces were treated with the three best enzymes, Subtilisin protease and lipase; dextranase; and polygalacturonase (PG) based enzymes, at neutral pH (~7) and doses of 50, 100, and 150 ppm. Contact times were 18 and 36 h. Live/dead staining, epifluorescence microscopy measurements, and 5 μm thick cryo-sections of enzyme and physically treated biofouled membranes revealed that Subtilisin protease- and lipase-based enzymes at 100 ppm and 18 h contact time were optimal for removing most of the cells and proteins from the RO surface. Culturable cells inside the biofilm declined by more than five logs even at the lower dose (50 ppm) and shorter incubation period (18 h). Subtilisin protease- and lipase-based enzyme cleaning at 100 ppm and for 18 h contact time restored the hydrophobicity of the TFC RO surface to its virgin condition while physical cleaning alone resulted in a 50° increase in hydrophobicity. Moreover, at this optimum working condition, the Subtilisin protease- and lipase-based enzyme treatment of biofouled RO surface also restored the surface roughness measured with atomic force microscopy and the mass percentage of the chemical compositions on the TFC surface estimated with X-ray photoelectron spectroscopy to its virgin condition. This novel study will encourage the further development and application of enzymes to remove biofoulants on the RO surface without changing its surface properties.
KW - biofouling
KW - enzymatic cleaning
KW - polygalacturonases, protease, lipase and dextranase
KW - surface property characterization
KW - thin-film composite reverse osmosis membrane
U2 - 10.1080/08927014.2013.852540
DO - 10.1080/08927014.2013.852540
M3 - Journal article
C2 - 24329165
AN - SCOPUS:84892990245
VL - 30
SP - 153
EP - 167
JO - Biofouling
JF - Biofouling
SN - 0892-7014
IS - 2
ER -
ID: 254669853