Simulation of cake layer topography in heterotrophic microalgae harvesting based on interface modified diffusion-limited-aggregation (IMDLA) and its implications for membrane fouling control

In order to alleviate membrane fouling and improve removal efficiency, a series of pretreatment technologies were applied to the ultrafiltration process. In this study, ClO2 was used as a pre-oxidation strategy for the ultrafiltration (UF) process. Humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA) were used as three typical organic model foulants, and the mixture of the three substances was used as a representation of simulated natural water. The dosages of ClO2 were 0.5, 1, 2, 4, and 8 mg/L, with 90 min pre-oxidation. The results showed that ClO2 pre-oxidation at low doses (1–2 mg/L) could alleviate the membrane flux decline caused by humus, polysaccharides, and simulated natural water, but had a limited alleviating effect on the irreversible resistance of the membrane. The interfacial free energy analysis showed that the interaction force between the membrane and the simulated natural water was also repulsive after the pre-oxidation, indicating that ClO2 pre-oxidation was an effective way to alleviate cake layer fouling by reducing the interaction between the foulant and the membrane. In addition, ClO2 oxidation activated the hidden functional groups in the raw water, resulting in an increase in the fluorescence value of humic analogs, but had a good removal effect on the fluorescence intensity of BSA. Furthermore, the membrane fouling fitting model showed that ClO2, at a low dose (1 mg/L), could change the mechanism of membrane fouling induced by simulated natural water from standard blocking and cake layer blocking to critical blocking. Overall, ClO2 pre-oxidation was an efficient pretreatment strategy for UF membrane fouling alleviation, especially for the fouling control of HA and SA at low dosages.

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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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Ozone Chemically Enhanced Backwash for Ceramic Membrane Fouling Control in Cyanobacteria-Laden Water

Membranes ◽

10.3390/membranes10090213 ◽

2020 ◽

Vol 10 (9) ◽

pp. 213

Author(s):

Stéphane Venne ◽

Onita D. Basu ◽

Benoit Barbeau

Keyword(s):

Surface Water ◽

Surface Waters ◽

Membrane Fouling ◽

Ceramic Membrane ◽

Membrane Surface ◽

Operating Costs ◽

Fouling Control ◽

Dead End ◽

Cake Layer ◽

Flow Experiments

Membrane fouling in surface waters impacted by cyanobacteria is currently poorly controlled and results in high operating costs. A chemically enhanced backwash (CEB) is one possible strategy to mitigate cyanobacteria fouling. This research investigates the potential of using an ozone CEB to control the fouling caused by Microcystis aeruginosa in filtered surface water on a ceramic ultrafiltration membrane. Batch ozonation tests and dead-end, continuous flow experiments were conducted with ozone doses between 0 and 19 mg O3/mg carbon. In all tests, the ozone was shown to react more rapidly with the filtered surface water foulants than with cyanobacteria. In addition, the ozone CEB demonstrated an improved mitigation of irreversible fouling over 2 cycles versus a single CEB cycle; indicating that the ozone CEB functioned better as the cake layer developed. Ozone likely weakens the compressible cake layer formed by cyanobacteria on the membrane surface during filtration, which then becomes more hydraulically reversible. In fact, the ozone CEB reduced the fouling resistance by 35% more than the hydraulic backwash when the cake was more compressed.

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Tilted membrane panel: A new module concept to maximize the impact of air bubbles for membrane fouling control in microalgae harvesting

Bioresource Technology ◽

10.1016/j.biortech.2017.05.175 ◽

2017 ◽

Vol 241 ◽

pp. 661-668 ◽

Cited By ~ 41

Author(s):

A. Eliseus ◽

M.R. Bilad ◽

N.A.H.M. Nordin ◽

Z.A. Putra ◽

M.D.H. Wirzal

Keyword(s):

Membrane Fouling ◽

Air Bubbles ◽

Fouling Control ◽

Microalgae Harvesting ◽

The Impact

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Maximizing the Impact of Air Bubbles for Membrane Fouling Control in Microalgae Harvesting

The Journal of The Institution of Engineers, Malaysia ◽

10.54552/v78i1.14 ◽

2017 ◽

Vol 78 (1) ◽

Author(s):

Arthur Eliseus ◽

Muhammad Roil Bilad

Keyword(s):

Membrane Fouling ◽

Membrane Surface ◽

Air Bubbles ◽

Membrane Cleaning ◽

Shear Rates ◽

Fouling Control ◽

Microalgae Harvesting ◽

Switching Mode ◽

The Impact ◽

Better Than

Harvesting microalgae using membrane is challenging due to the nature of microalgae having very high membrane fouling potential. Numerous techniques have been proposed for membrane fouling control, including optimizing operational cycles, imposing shear-rates via air bubbles and dosing chemicals for feed conditioning and membrane cleaning. As an established method, the eficacy of air bubbles for membrane fouling control can be improved by maximizing the impact of shear-rates in scouring foulant from the membrane surface. In this study, we investigate the effect of tilting angles, switching periods as well as aeration rates in a lab-scale submerged iltration system by iltering microalgae solution. Results showed that higher tilting angles improve the cleaning eficiency by offering higher lux of up to 2.7 times at an angle of 20◦ as opposed to the vertical one. It was also found that operating a one-sided panel (without switching) was about 20% better than a two-sided panel, in which the latter involved switching mode to offer aeration of both panel sides. This technique is effective in controlling fouling and can lead to energy saving for full-scale modules.

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Comparing powdered and granular activated carbon addition on membrane fouling control through evaluating the impacts on mixed liquor and cake layer properties in anaerobic membrane bioreactors

Bioresource Technology ◽

10.1016/j.biortech.2019.122137 ◽

2019 ◽

Vol 294 ◽

pp. 122137 ◽

Cited By ~ 5

Author(s):

Shuming Yang ◽

Qian Zhang ◽

Zhen Lei ◽

Wen Wen ◽

Xingyuan Huang ◽

...

Keyword(s):

Activated Carbon ◽

Membrane Fouling ◽

Granular Activated Carbon ◽

Membrane Bioreactors ◽

Carbon Addition ◽

Mixed Liquor ◽

Fouling Control ◽

Cake Layer ◽

Anaerobic Membrane Bioreactors

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Mechanism of Membrane Fouling Control by HMBR: Effect of Microbial Community on EPS

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17051681 ◽

2020 ◽

Vol 17 (5) ◽

pp. 1681

Author(s):

Qiang Liu ◽

Ying Yao ◽

Delan Xu

Keyword(s):

Microbial Community ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Extracellular Polymeric Substances ◽

Microbial Community Composition ◽

Domestic Wastewater ◽

Control Group ◽

Transmembrane Pressure ◽

Fouling Control ◽

Cake Layer

A hybrid membrane bioreactor (HMBR) employing activated sludge and biofilm simultaneously is proved to represent a good performance on membrane fouling control compared to conventional membrane bioreactor (CMBR) by reducing extracellular polymeric substances (EPS), especially bound EPS (B-EPS). In order to better understand the mechanism of membrane fouling control by the HMBR in regard of microbial community composition, a pilot scale HMBR operated to treat domestic wastewater for six months, and a CMBR operated at the same time as control group. Results showed that HMBR can effectively control membrane fouling. When transmembrane pressure reached 0.1 MPa, the membrane module in the HMBR operated for about 26.7% longer than that in the CMBR. In the HMBR, the quantity of EPS was significantly lower than that in the CMBR. In this paper, soluble EPS was also found to have a close relationship with cake layer resistance. The species richness and diversity in the HMBR were higher than those in the CMBR, and a certain difference between the compositions of microbial communities in the two reactors was confirmed. Therefore, the difference in microbial community compositions may be the direct reason why EPS in the HMBR was lower than that in the CMBR.

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Investigation of membrane fouling mechanism of intracellular organic matter during ultrafiltration

Scientific Reports ◽

10.1038/s41598-020-79272-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Weiwei Huang ◽

Yuanhong Zhu ◽

Bingzhi Dong ◽

Weiwei Lv ◽

Quan Yuan ◽

...

Keyword(s):

Organic Matter ◽

Chlorella Vulgaris ◽

Membrane Fouling ◽

Membrane Surface ◽

Layer Formation ◽

Fouling Control ◽

Fouling Mechanism ◽

Cake Layer ◽

Severe Degree ◽

Filtration Flux

AbstractThis study investigated the ultrafiltration (UF) membrane fouling mechanism of intracellular organic matter (IOM) from Chlorella vulgaris (CV) and Microcystis aeruginosa (MA). Both CV- and MA-IOM caused severe membrane fouling during UF; however, there were significant differences in the membrane fouling by these two materials. Neutral hydrophilic (N-HPI) compounds were the organics that caused the most severe membrane fouling during CV-IOM filtration, whereas the MA-IOM membrane fouling was induced by mainly hydrophobic (HPO) organics. From an analysis based on Derjaguin–Landau–Verwey–Overbeek theory, it was found that the interaction energy between the membrane and foulants in the later stage of filtration was the major factor determining the efficiency of filtration for both CV-IOM and MA-IOM. The TPI organics in CV-IOM fouled the membrane to a more severe degree during the initial filtration flux; however, when the membrane surface was covered with CV-IOM foulants, the N-HPI fraction of CV-IOM caused the most severe membrane fouling because its attractive energy with the membrane was the highest. For MA-IOM, regardless of the initial filtration flux or the late stage of filtration, the HPO organics fouled the membrane to the greatest extent. An analysis of modified filtration models revealed that cake layer formation played a more important role than other fouling mechanisms during the filtration of CV-IOM and MA-IOM. This study provides a significant understanding of the membrane fouling mechanism of IOM and is beneficial for developing some strategies for membrane fouling control when treating MA and CV algae-laden waters.

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