Effects of ionic strength on membrane fouling in a membrane bioreactor.
In this study, the effects of ionic strength on membrane fouling in a membrane bioreactor (MBR) were investigated. Ionic strength in range of 0.005-0.05mol/L exerted no apparent impacts on the resistance of virgin membrane, fouled membrane and pore clogging. Thermodynamic analysis showed existences of a secondary energy minimum and an energy barrier in the process of the sludge flocs approaching to membrane surface. Increase in ionic strength could significantly reduce the energy barrier. It was revealed that there existed a critical ionic strength above that the energy barrier would disappear, facilitating adhesion of the foulants. Cake resistance was not significantly affected by the ionic strength, but highly depended on SMP in supernatant. The high cake resistance caused by SMP could be explained by the osmotic pressure mechanism. The obtained results provided new insights into membrane fouling in MBRs.
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
Fangyuan
F
Wang
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
Meijia
M
Zhang
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
Wei
W
Peng
Department of Materials Physics, Zhejiang Normal University, Jinhua 321004, PR China.
Yiming
Y
He
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China. Electronic address: hjlin@zjnu.cn.
Hongjun
H
Lin
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
Jianrong
J
Chen
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
Huachang
H
Hong
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
Aijun
A
Wang
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
Haiying
H
Yu
D001419:Bacteria / Q000737:chemistry; D057219:Biofouling; D019149:Bioreactors; D005374:Filtration; D008567:Membranes, Artificial; D009994:Osmolar Concentration; D016062:Porosity; D012722:Sewage / Q000737:chemistry; D012995:Solubility; D013500:Surface Tension; D013816:Thermodynamics
D008567:Membranes, Artificial; D012722:Sewage
Critical ionic strength; Energy barrier; Membrane bioreactor; Membrane fouling