TY - JOUR
T1 - Removal of antibiotic-resistant bacteria and antibiotic resistance genes affected by varying degrees of fouling on anaerobic microfiltration membranes
AU - Cheng, Hong
AU - Hong, Pei-Ying
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): FCC/1/1971-06-01
Acknowledgements: The authors thank Mr. Qingtian Guan for providing technical assistance with plasmid assemblies. The authors thank Dr. Tiannyu Wang for creating the GFP-positive E. coli PI-7 strain. This study is supported by KAUST Center Competitive Funding, grant no. FCC/1/1971-06-01, awarded to P.-Y.H.
PY - 2017/10/10
Y1 - 2017/10/10
N2 - An anaerobic membrane bioreactor was retrofitted with polyvinylidene fluoride (PVDF) microfiltration membrane units, each of which was fouled to a different extent. The membranes with different degrees of fouling were evaluated for their efficiencies in removing three antibiotic-resistant bacteria (ARB), namely, blaNDM-1-positive Escherichia coli PI-7, blaCTX-M-15-positive Klebsiella pneumoniae L7, and blaOXA-48-positive E. coli UPEC-RIY-4, as well as their associated plasmid-borne antibiotic resistance genes (ARGs). The results showed that the log removal values (LRVs) of ARGs correlated positively with the extent of membrane fouling and ranged from 1.9 to 3.9. New membranes with a minimal foulant layer could remove more than 5 log units of ARB. However, as the membranes progressed to subcritical fouling, the LRVs of ARB decreased at increasing operating transmembrane pressures (TMPs). The LRV recovered back to 5 when the membrane was critically fouled, and the achieved LRV remained stable at different operating TMPs. Furthermore, characterization of the surface attributed the removal of both the ARB and ARGs to adsorption, which was facilitated by an increasing hydrophobicity and a decreasing surface ζ potential as the membranes fouled. Our results indicate that both the TMP and the foulant layer synergistically affected ARB removal, but the foulant layer was the main factor that contributed to ARG removal.
AB - An anaerobic membrane bioreactor was retrofitted with polyvinylidene fluoride (PVDF) microfiltration membrane units, each of which was fouled to a different extent. The membranes with different degrees of fouling were evaluated for their efficiencies in removing three antibiotic-resistant bacteria (ARB), namely, blaNDM-1-positive Escherichia coli PI-7, blaCTX-M-15-positive Klebsiella pneumoniae L7, and blaOXA-48-positive E. coli UPEC-RIY-4, as well as their associated plasmid-borne antibiotic resistance genes (ARGs). The results showed that the log removal values (LRVs) of ARGs correlated positively with the extent of membrane fouling and ranged from 1.9 to 3.9. New membranes with a minimal foulant layer could remove more than 5 log units of ARB. However, as the membranes progressed to subcritical fouling, the LRVs of ARB decreased at increasing operating transmembrane pressures (TMPs). The LRV recovered back to 5 when the membrane was critically fouled, and the achieved LRV remained stable at different operating TMPs. Furthermore, characterization of the surface attributed the removal of both the ARB and ARGs to adsorption, which was facilitated by an increasing hydrophobicity and a decreasing surface ζ potential as the membranes fouled. Our results indicate that both the TMP and the foulant layer synergistically affected ARB removal, but the foulant layer was the main factor that contributed to ARG removal.
UR - http://hdl.handle.net/10754/626022
UR - http://pubs.acs.org/doi/abs/10.1021/acs.est.7b03798
UR - http://www.scopus.com/inward/record.url?scp=85042556904&partnerID=8YFLogxK
U2 - 10.1021/acs.est.7b03798
DO - 10.1021/acs.est.7b03798
M3 - Article
C2 - 28957626
SN - 0013-936X
VL - 51
SP - 12200
EP - 12209
JO - Environmental Science & Technology
JF - Environmental Science & Technology
IS - 21
ER -