TY - JOUR
T1 - Relation between sludge properties and filterability in MBR
T2 - Under infinite SRT
AU - Zhang, Haifeng
AU - Wang, Bing
AU - Yu, Haihuan
AU - Zhang, Lanhe
AU - Song, Lianfa
N1 - Publisher Copyright:
© 2015 Techno-Press, Ltd.
PY - 2015
Y1 - 2015
N2 - A laboratory-scale submerged membrane bioreactor (MBR) was continuously operated for 100 d at an infinite sludge retention time (SRT) with the aim of identifying possible relation between the filterability of mixed liquor and sludge properties, such as extracellular polymeric substances (EPS), soluble microbial products (SMP), viscosity of mixed liquor, zeta potential of flocs and particle size distributions (PSD). Research results confirmed that MBR can operate with a complete sludge retention ensuring good treatment performances for COD and NH3-N. However, the long term operation (about 40 d) of MBR with no sludge discharge had a negative influence on sludge filterability, and an increase in membrane fouling rates with the time was observed. There as a strong correlation between the sludge filterability and the fouling rate. Among the different sludge properties parameters, the concentration SMP and EPS had a more closely correlation with the sludge filterability. The concentrations of SMP, especially SMP with MW above 10 kDa, had a strong direct correlation to the filterability of mixed sludge. The protein fractions in EPS were biodegradable and available for microorganism metabolism after about 60 days, and the carbohydrates in EPS had a significantly negative effect on sludge filterability in MBR at an infinite SRT.
AB - A laboratory-scale submerged membrane bioreactor (MBR) was continuously operated for 100 d at an infinite sludge retention time (SRT) with the aim of identifying possible relation between the filterability of mixed liquor and sludge properties, such as extracellular polymeric substances (EPS), soluble microbial products (SMP), viscosity of mixed liquor, zeta potential of flocs and particle size distributions (PSD). Research results confirmed that MBR can operate with a complete sludge retention ensuring good treatment performances for COD and NH3-N. However, the long term operation (about 40 d) of MBR with no sludge discharge had a negative influence on sludge filterability, and an increase in membrane fouling rates with the time was observed. There as a strong correlation between the sludge filterability and the fouling rate. Among the different sludge properties parameters, the concentration SMP and EPS had a more closely correlation with the sludge filterability. The concentrations of SMP, especially SMP with MW above 10 kDa, had a strong direct correlation to the filterability of mixed sludge. The protein fractions in EPS were biodegradable and available for microorganism metabolism after about 60 days, and the carbohydrates in EPS had a significantly negative effect on sludge filterability in MBR at an infinite SRT.
KW - Activated sludge; soluble microbial products (SMP); extracellular polymeric substances (EPS)
KW - Membrane bioreactor (MBR)
KW - Sludge retention time (SRT)
UR - http://www.scopus.com/inward/record.url?scp=84949777770&partnerID=8YFLogxK
U2 - 10.12989/mwt.2015.6.6.501
DO - 10.12989/mwt.2015.6.6.501
M3 - Article
AN - SCOPUS:84949777770
VL - 6
SP - 501
EP - 512
JO - Membrane Water Treatment
JF - Membrane Water Treatment
SN - 2005-8624
IS - 6
ER -