TY - JOUR
T1 - Low concentrations of Al(III) accelerate the formation of biofilm
T2 - Multiple effects of hormesis and flocculation
AU - Cui, Xiaochun
AU - Huo, Mingxin
AU - Chen, Congli
AU - Yu, Zhisen
AU - Zhou, Chen
AU - Li, Anran
AU - Qiao, Bingqian
AU - Zhou, Dandan
AU - Crittenden, John C.
N1 - Funding Information:
The authors thank the National Natural Science Foundation of China ( 51722803 and 51578117 ), and the Fundamental Research Funds for the Central Universities ( 2412016KJ011 ) for their financial support. The authors also would like to acknowledge the support by Long Term Program in “1000 Talent Plan for High-Level Foreign Experts” (WQ20142200209), Jilin Engineering Research Centre for Municipal Wastewater Treatment and Water Quality Protection, the Brook Byers Institute for Sustainable Systems, Hightower Chair, and the Georgia Research Alliance at the Georgia Institute of Technology.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Residual Al(III) (at low concentration) is common in water treatment plants (WTPs) and is associated with bacteria. We hypothesize that Al(III) accelerate biofouling due to its hydrolysis and hormesis characteristics, as compared with other cations. To verify this, we elaborated the roles of Al(III) at low concentrations on the biofilm formation. Al(III) hormesis (<2.0 mg/L) stimulated bacteria growth increased by ~3.7 times, and extracellular polymeric substances production also enhanced. Al(III) flocculation resulted in the suspended cells precipitation instantly, for Al(III) dosages of 0.6 and 2.0 mg/L and the concentration of Al(III) decreased by 0.07 and 0.14 mg/L, respectively. Al(III) poisoned the bridged bacterial cells and decreased their ATP by 22.36% and 55.91%, respectively. Al(III) formed polymer presented strong affinity with bacterial outer membrane, and this damaged the bacterial outer membrane. This caused proteins to leak at the combined point. Al-polymer bound to –NH2 and/or –NH– on the leaked protein, contributed to biofilm formation. Biofilm maturity was aided by polysaccharides, which shielded Al(III) toxicity for the formed biofilm. Thus, the biofilm exhibited a distinguished double-layer microstructure, principally with proteins and inactivated cells at the bottom, polysaccharides and activated cells at the top. Thus, hormesis and flocculation caused by low concentration Al(III) mutually promoted each other, and together accelerated biofilm formation.
AB - Residual Al(III) (at low concentration) is common in water treatment plants (WTPs) and is associated with bacteria. We hypothesize that Al(III) accelerate biofouling due to its hydrolysis and hormesis characteristics, as compared with other cations. To verify this, we elaborated the roles of Al(III) at low concentrations on the biofilm formation. Al(III) hormesis (<2.0 mg/L) stimulated bacteria growth increased by ~3.7 times, and extracellular polymeric substances production also enhanced. Al(III) flocculation resulted in the suspended cells precipitation instantly, for Al(III) dosages of 0.6 and 2.0 mg/L and the concentration of Al(III) decreased by 0.07 and 0.14 mg/L, respectively. Al(III) poisoned the bridged bacterial cells and decreased their ATP by 22.36% and 55.91%, respectively. Al(III) formed polymer presented strong affinity with bacterial outer membrane, and this damaged the bacterial outer membrane. This caused proteins to leak at the combined point. Al-polymer bound to –NH2 and/or –NH– on the leaked protein, contributed to biofilm formation. Biofilm maturity was aided by polysaccharides, which shielded Al(III) toxicity for the formed biofilm. Thus, the biofilm exhibited a distinguished double-layer microstructure, principally with proteins and inactivated cells at the bottom, polysaccharides and activated cells at the top. Thus, hormesis and flocculation caused by low concentration Al(III) mutually promoted each other, and together accelerated biofilm formation.
KW - Aluminum
KW - Biofilm
KW - Coagulant
KW - Flocculation
KW - Hormesis
KW - Toxicity
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U2 - 10.1016/j.scitotenv.2018.03.376
DO - 10.1016/j.scitotenv.2018.03.376
M3 - Article
C2 - 29631141
AN - SCOPUS:85045008168
SN - 0048-9697
VL - 634
SP - 516
EP - 524
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -