Finned spacer for enhancing the impact of air bubbles for membrane fouling control in Chlorella vulgaris filtration

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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Improving membrane fouling control by maximizing the impact of air bubbles shear in a submerged plate-and-frame membrane module

10.1063/1.5005372 ◽

2017 ◽

Author(s):

A. Eliseus ◽

M. R. Bilad

Keyword(s):

Membrane Fouling ◽

Membrane Module ◽

Air Bubbles ◽

Fouling Control ◽

Submerged Plate ◽

The Impact

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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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Patterned Membrane in an Energy-Efficient Tilted Panel Filtration System for Fouling Control in Activated Sludge Filtration

Polymers ◽

10.3390/polym12020432 ◽

2020 ◽

Vol 12 (2) ◽

pp. 432 ◽

Cited By ~ 7

Author(s):

Aisyah Osman ◽

Normi Izati Mat Nawi ◽

Shafirah Samsuri ◽

Muhammad Roil Bilad ◽

Norazanita Shamsuddin ◽

...

Keyword(s):

Activated Sludge ◽

Membrane Fouling ◽

Membrane Surface ◽

Aeration Rate ◽

Membrane Bioreactors ◽

Widespread Application ◽

Membrane Area ◽

Surface Corrugation ◽

Fouling Control ◽

The Impact

A membrane bioreactor enhances the overall biological performance of a conventional activated sludge system for wastewater treatment by producing high-quality effluent suitable for reuse. However, membrane fouling hinders the widespread application of membrane bioreactors by reducing the hydraulic performance, shortening membrane lifespan, and increasing the operational costs for membrane fouling management. This study assesses the combined effect of membrane surface corrugation and a tilted panel in enhancing the impact of air bubbling for membrane fouling control in activated sludge filtration, applicable for membrane bioreactors. The filterability performance of such a system was further tested under variable parameters: Filtration cycle, aeration rate, and intermittent aeration. Results show that a combination of surface corrugation and panel tilting enhances the impact of aeration and leads to 87% permeance increment. The results of the parametric study shows that the highest permeance was achieved under short filtration–relaxation cycle of 5 min, high aeration rate of 1.5 L/min, and short switching period of 2.5 min, to yield the permeances of 465 ± 18, 447 ± 2, and 369 ± 9 L/(m2h bar), respectively. The high permeances lead to higher operational flux that helps to lower the membrane area as well as energy consumption. Initial estimation of the fully aerated system yields the energy input of 0.152 kWh/m3, much lower than data from the full-scale references of <0.4 kWh/m3. Further energy savings and a lower system footprint can still be achieved by applying the two-sided panel with a switching system, which will be addressed in the future.

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Aquatic Toxicity of Photocatalyst Nanoparticles to Green Microalgae Chlorella vulgaris

Water ◽

10.3390/w13010077 ◽

2020 ◽

Vol 13 (1) ◽

pp. 77

Author(s):

Cristina Adochite ◽

Luminita Andronic

Keyword(s):

Chlorella Vulgaris ◽

Advanced Oxidation Process ◽

Growth Parameters ◽

Aquatic Toxicity ◽

Basal Medium ◽

Inhibitory Effect ◽

Synthesis Methods ◽

Potent Inhibitory Effect ◽

Density Surface ◽

The Impact

In the last years, nanoparticles such as TiO2, ZnO, NiO, CuO and Fe2O3 were mainly used in wastewater applications. In addition to the positive aspects concerning using nanoparticles in the advanced oxidation process of wastewater containing pollutants, the impact of these nanoparticles on the environment must also be investigated. The toxicity of nanoparticles is generally investigated by the nanomaterials’ effect on green algae, especially on Chlorella vulgaris. In this review, several aspects are reviewed: the Chlorella vulgaris culture monitoring and growth parameters, the effect of different nanoparticles on Chlorella vulgaris, the toxicity of photocatalyst nanoparticles, and the mechanism of photocatalyst during oxidative stress on the photosynthetic mechanism of Chlorella vulgaris. The Bold basal medium (BBM) is generally recognized as an excellent standard cultivation medium for Chlorella vulgaris in the known environmental conditions such as temperature in the range 20–30 °C and light intensity of around 150 μE·m2·s−1 under a 16/8 h light/dark cycle. The nanoparticles synthesis methods influence the particle size, morphology, density, surface area to generate growth inhibition and further algal deaths at the nanoparticle-dependent concentration. Moreover, the results revealed that nanoparticles caused a more potent inhibitory effect on microalgal growth and severely disrupted algal cells’ membranes.

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Effect of IX dosing on polypropylene and PVDF membrane fouling control

Water Research ◽

10.1016/j.watres.2013.03.056 ◽

2013 ◽

Vol 47 (11) ◽

pp. 3827-3834 ◽

Cited By ~ 13

Author(s):

Darli Theint Myat ◽

Max Mergen ◽

Oliver Zhao ◽

Matthew B. Stewart ◽

John D. Orbell ◽

...

Keyword(s):

Membrane Fouling ◽

Pvdf Membrane ◽

Fouling Control

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The combination effect of preozonation and CNTs layer modification on low-pressure membrane fouling control in treating NOM and EfOM

Journal of Membrane Science ◽

10.1016/j.memsci.2021.119225 ◽

2021 ◽

pp. 119225

Author(s):

Jin Guo ◽

Xuedong Zhu ◽

Qingshan Wang ◽

Weiyan Liu ◽

Yu Wang

Keyword(s):

Membrane Fouling ◽

Low Pressure ◽

Combination Effect ◽

Fouling Control

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Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽

10.3390/membranes11050369 ◽

2021 ◽

Vol 11 (5) ◽

pp. 369

Author(s):

Shengji Xia ◽

Xinran Zhang ◽

Yuanchen Zhao ◽

Fibor J. Tan ◽

Pan Li ◽

...

Keyword(s):

Water Treatment ◽

Membrane Fouling ◽

Membrane Filtration ◽

Ceramic Membrane ◽

Membrane Separation ◽

Membrane System ◽

Coagulation System ◽

Fouling Control ◽

Filtration System ◽

Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

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