Influence of temperature and temperature shock on sludge properties, cake layer structure, and membrane fouling in a submerged anaerobic membrane bioreactor

The effect of bamboo charcoal (BC) amendment on the anaerobic habitat such as alkalinity and membrane fouling in an anaerobic membrane bioreactor (AnMBR) was investigated in this study.

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Optimization of In Situ Backwashing Frequency for Stable Operation of Anaerobic Ceramic Membrane Bioreactor

Processes ◽

10.3390/pr8050545 ◽

2020 ◽

Vol 8 (5) ◽

pp. 545 ◽

Cited By ~ 1

Author(s):

Rathmalgodage Thejani Nilusha ◽

Tuo Wang ◽

Hongyan Wang ◽

Dawei Yu ◽

Junya Zhang ◽

...

Keyword(s):

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Bioreactor ◽

Ceramic Membrane ◽

Pure Water ◽

Ex Situ ◽

Stable Operation ◽

Chemical Cleaning ◽

Cake Layer

The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the major organic foulants were fulvic acid-like substances and humic acid-like substances. Proteobacteria, Firmucutes, Epsilonbacteria and Bacteroides were the major microbes attached to the ceramic membrane fouling layer which were effectively removed by NaOCl.

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Influence of COD:N ratio on sludge properties and their role in membrane fouling of a submerged membrane bioreactor

Water Research ◽

10.1016/j.watres.2015.11.052 ◽

2016 ◽

Vol 89 ◽

pp. 132-141 ◽

Cited By ~ 55

Author(s):

L. Hao ◽

S.N. Liss ◽

B.Q. Liao

Keyword(s):

Membrane Fouling ◽

Membrane Bioreactor ◽

Submerged Membrane Bioreactor ◽

Sludge Properties

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Exerting ultrasound to control the membrane fouling in filtration of anaerobic activated sludge—mechanism and membrane damage

Water Science & Technology ◽

10.2166/wst.2008.120 ◽

2008 ◽

Vol 57 (5) ◽

pp. 773-779 ◽

Cited By ~ 24

Author(s):

Xianghua Wen ◽

Pengzhe Sui ◽

Xia Huang

Keyword(s):

Activated Sludge ◽

Hydroxyl Radicals ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Chemical Interaction ◽

Membrane Surface ◽

Membrane Damage ◽

Operational Conditions ◽

Fouling Control ◽

Cake Layer

In this study, ultrasound was applied to control membrane fouling development online in an anaerobic membrane bioreactor (AMBR). Experimental results showed that membrane fouling could be controlled effectively by ultrasound although membrane damage may occur under some operational conditions. Based upon the observation on the damaged membrane surface via SEM, two mechanisms causing membrane damage by exerting ultrasound are inferred as micro particle collide on the membrane surface and chemical interaction between membrane materials and hydroxyl radicals produced by acoustic cavitations. Not only membrane damage but also membrane fouling control and membrane fouling cleaning were resulted from these mechanisms. Properly selecting ultrasonic intensity and working time, and keeping a certain thickness of cake layer on membrane surface could be effective ways to protect membrane against damage.

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Fouling cake layer in a submerged anaerobic membrane bioreactor treating saline wastewaters: curse or a blessing?

Water Science & Technology ◽

10.2166/wst.2011.461 ◽

2011 ◽

Vol 63 (12) ◽

pp. 2902-2908 ◽

Cited By ~ 27

Author(s):

I. Vyrides ◽

D. C. Stuckey

Keyword(s):

Membrane Fouling ◽

Membrane Bioreactor ◽

Large Fraction ◽

Membrane Bioreactors ◽

Extracellular Polysaccharides ◽

Cake Layer ◽

Anaerobic Membrane Bioreactors ◽

Suspended Biomass ◽

Microbial Products

The treatment of inhibitory (saline) wastewaters is known to produce considerable amounts of soluble microbial products (SMPs), and this has been implicated in membrane fouling; the fate of these SMPs was of considerable interest in this work. This study also investigated the contribution of SMPs to membrane fouling of the; (a) cake layer/biofilm layer, (b) the compounds below the biofilm/cake layer and strongly attached to the surface of the membrane, (c) the compounds in the inner pores of the membrane, and (d) the membrane. It was found that the cake/biofilm layer was the main reason for fouling of the membrane. Interestingly, the bacteria attached to the cake/biofilm layer showed higher biodegradation rates compared with the bacteria in suspension. Moreover, the bacteria attached to the cake layer showed higher amounts of attached extracellular polysaccharides (EPS) compared with the bacteria in suspension, possibly due to accumulation of the released EPS from suspended biomass in the cake/biofilm layer. Molecular weight (MW) analysis of the effluent and reactor bulk showed that the cake layer can retain a large fraction of the SMPs in the reactor and prevent them from being released into the effluent. Hence, while cake layers lead to lower fluxes in submerged anaerobic membrane bioreactors (SAMBRs), and hence higher costs, they can improve the quality of the reactor effluent.

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