TY - JOUR
T1 - Membrane bioreactor vs. oxidation ditch
T2 - Full-scale long-term performance related with mixed liquor seasonal characteristics
AU - Sun, Jianyu
AU - Xiao, Kang
AU - Yan, Xiaoxu
AU - Liang, Peng
AU - Shen, Yue Xiao
AU - Zhu, Ningwei
AU - Huang, Xia
N1 - Funding Information:
This work was supported by the International Program of MOST of China (No. 2013DFG92240), the Program for Outstanding PhD thesis of Beijing (No. 20131000305) and the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT1152). We also greatly appreciate the support and help of those at the wastewater treatment plant during the experiment.
Publisher Copyright:
© 2015 Elsevier Ltd. All rights reserved.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - The relative strengths of membrane bioreactors (MBR) versus conventional activated sludge (CAS) processes have long been debated, but never compared systematically at full scale. To this end, we monitored full-scale wastewater treatment performance and mixed-liquor characteristics (sludge biomass, extracellular polymeric substances (EPS), supernatant with molecular weight and hydrophilic/hydrophobic distribution) for parallel MBR and CAS (via oxidation ditch - OD), for a year. Ammonia and suspended solids were better removed by MBR; temperature affected ammonia removal in OD. At low temperatures, sludge settlement declined in both processes, but solid-liquid separation via membrane filtration continued, although the membrane fouled. EPS characteristics were similar, and organic components in EPS and supernatant varied seasonally, in both processes. MBR had a lower production rate, but higher concentration, of supernatant organics and accumulated large molecular-weight polysaccharides. Ammonia removal was correlated with tightly bound proteinaceous EPS. Polysaccharides, in loosely bound EPS and supernatant, were responsible for effective settlement (OD), and membrane fouling (MBR). These results demonstrate how mixed liquor intermediates process and performance, and that performance depends on effective solid-liquid separation. MBRs excel when stringent requirements for pollutant-removal and extreme environmental conditions exist. The much cheaper OD remains competitive under less demanding conditions.
AB - The relative strengths of membrane bioreactors (MBR) versus conventional activated sludge (CAS) processes have long been debated, but never compared systematically at full scale. To this end, we monitored full-scale wastewater treatment performance and mixed-liquor characteristics (sludge biomass, extracellular polymeric substances (EPS), supernatant with molecular weight and hydrophilic/hydrophobic distribution) for parallel MBR and CAS (via oxidation ditch - OD), for a year. Ammonia and suspended solids were better removed by MBR; temperature affected ammonia removal in OD. At low temperatures, sludge settlement declined in both processes, but solid-liquid separation via membrane filtration continued, although the membrane fouled. EPS characteristics were similar, and organic components in EPS and supernatant varied seasonally, in both processes. MBR had a lower production rate, but higher concentration, of supernatant organics and accumulated large molecular-weight polysaccharides. Ammonia removal was correlated with tightly bound proteinaceous EPS. Polysaccharides, in loosely bound EPS and supernatant, were responsible for effective settlement (OD), and membrane fouling (MBR). These results demonstrate how mixed liquor intermediates process and performance, and that performance depends on effective solid-liquid separation. MBRs excel when stringent requirements for pollutant-removal and extreme environmental conditions exist. The much cheaper OD remains competitive under less demanding conditions.
KW - Conventional activated sludge
KW - Membrane bioreactor
KW - Mixed liquor characteristics
KW - Seasonal variation
KW - Wastewater treatment performance
UR - http://www.scopus.com/inward/record.url?scp=84949113501&partnerID=8YFLogxK
U2 - 10.1016/j.procbio.2015.09.010
DO - 10.1016/j.procbio.2015.09.010
M3 - Article
AN - SCOPUS:84949113501
VL - 50
SP - 2224
EP - 2233
JO - Process Biochemistry
JF - Process Biochemistry
SN - 1359-5113
IS - 12
ER -