(50b) Performance of a Submerged Anaerobic Membrane Bioreactor (AnMBR) at Long HRT and High Solid Concentration: Focusing on Membrane Fouling and Effluent Quality

Performance of a
submerged anaerobic membrane bioreactor (AnMBR) at long HRT and high solid
concentration: focusing on membrane fouling and effluent quality

Yifru Waktole Berkessa^1,
2, Binghua Yan^1*, Ming Tan¹, Yang Zhang^1*

¹
Lab of Waste Valorization and Water Reuse, Qingdao Institute of Bioenergy and
Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Laoshan
District, Qingdao 266101, PR China

²
University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049,
PR China

Corresponding author e-mail: zhangyang@qibebt.ac.cn, yanbh@qibebt.ac.cn

Aerobic membrane bioreactor is proved to
be efficient for wastewater treatment and its application is widespread. However,
it has drawbacks of high energy consumption and high solid yield. Interests in
anaerobic membrane bioreactor (AnMBR) have increased in the last three decades due
to its low energy consumption, low sludge production and biogas generation. Despite
its merits membrane fouling is bottleneck to AnMBR technology and this study
aimed at assessing treatment performance and mitigate membrane fouling by using
newly designed submerged AnMBR under high MLSS concentration (22.30 g/l) and
long HRT (47days). Submerged AnMBRs (two) ran in parallel with three phase
separator placed between bulk sludge and membrane module. Microfiltration (0.40µm)
membrane modules with effective total filtration area of 0.14m² were
installed. Results showed steady COD removal (average COD removal of >98%),
high specific flux and mean biogas generation of
0.29 LCH₄/g COD _removed. The later could be due to
active methanogens and syntrophic bacteria
abundant in the sludge as confirmed from high-throughput sequencing of 16s rRNA targeting bacterial and archaeal community.
Effluent quality analysis showed the effluent
soluble microbial products were dominated by proteins compared to
carbohydrates. Besides from specific ultraviolet absorbance (SUVA) analysis, effluent
from both reactors had low aromaticity with SUVA <1 (L¡¤mg^-1¡¤M^-1)
except for the first ten days. Furthermore, mean total resistance of
both reactors (2.23E+09 m^-1)
and fouling rate (4.0E+08m^-1¡¤day^-1)
values over course of operation time were low compared to literature values (usually
>E+10 for both resistance and fouling rate) which could suggest the newly
designed AnMBR mitigated fouling and produce effluent with better quality.

Key words: Anaerobic
membrane bioreactor; mixed liquor suspended solid; membrane fouling; membrane
flux

Acknowledgement: Financial
support of the Shandong Provincial Natural Science Foundation (ZR2016bb06) and
¡°100 Talents Program¡± of Chinese Academy of Sciences (CAS).