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

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.

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

2020 ◽  
Vol 11 ◽  
pp. 100429 ◽  
Author(s):  
Nik Nurul Ain Nabilah Razak ◽  
Ratri Rahmawati ◽  
Muhammad Roil Bilad ◽  
Amalia Enggar Pratiwi ◽  
Muthia Elma ◽  
...  
Keyword(s):  
Chlorella Vulgaris ◽  
Membrane Fouling ◽  
Air Bubbles ◽  
Fouling Control ◽  
The Impact

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

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 432 ◽  
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.

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

2008 ◽  
Vol 57 (5) ◽  
pp. 773-779 ◽  
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.

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

Membranes ◽  
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.

scholarly journals The impact of anionic polyacrylamide (APAM) on ultrafiltration efficiency in flocculation-ultrafiltration process

2017 ◽  
Vol 75 (8) ◽  
pp. 1982-1989 ◽  
Author(s):  
Ruijun Zhang ◽  
Shengnan Yuan ◽  
Wenxin Shi ◽  
Cong Ma ◽  
Zhiqiang Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Aluminium Chloride ◽  
Optimal Dosage ◽  
Cleaning Efficiency ◽  
Chemical Cleaning ◽  
Membrane Cleaning ◽  
Effluent Quality ◽  
Adsorption Sites ◽  
The Impact ◽  
Anionic Polyacrylamide

With the purpose of improving the ultrafiltration (UF) efficiency, anionic polyacrylamide (APAM) has been used as a coagulant aid in the flocculation-UF process. In this study, the impact of APAM on UF efficiency has been investigated with regard to membrane fouling, membrane cleaning and effluent quality. The results indicated that the optimal dosage of APAM had positive impacts on membrane fouling control, membrane cleaning and effluent quality. According to the flux decline curve, scanning electron microscopy and contact angle characterization, the optimal dosage of APAM was determined to be 0.1 mg/L coupled with 2 mg/L (as Al3+) poly-aluminium chloride. Under this optimal condition, membrane fouling can be mitigated because of the formation of a porous and hydrophilic fouling layer. APAM in the fouling layer can improve the chemical cleaning efficiency of 0.5% NaOH due to the disintegration of the fouling layer when APAM is dissolved under strong alkaline conditions. Furthermore, with the addition of APAM in the flocculation-UF process, more active adsorption sites can be formed in the flocs as well as the membrane fouling layer, thus more antipyrine molecules in the raw water can be adsorbed and removed in the flocculation-UF process.

scholarly journals Design, construction and evaluation OFAN experimental ceramic membrane facility with investigation into fouling control

2021 ◽  
Author(s):  
Sarah Shim
Keyword(s):  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Ceramic Membranes ◽  
Membrane Unit ◽  
Membrane Cleaning ◽  
Fouling Control ◽  
Solids Concentration ◽  
Start Up ◽  
Water And Wastewater ◽  
Design Construction

During the past decade, the growth in membrane research and technology has advanced and multiplied in usage for many industries including water and wastewater. A major limitation of the application is due to membrane fouling. In this work, the construction, start-up calibration and testing of a membrane unit, as well as an examination into the fouling and cleaning aspect of the ceramic membranes are investigated. An aqueous solution containing precipitate is fed to the unit in order to observe fouling behaviour. Effluent wastewater from a bioreactor, CUBEN, is also tested with the unit and membrane cleaning is performed using various chemical agents. For both chemically enhanced backwash (CEB) and membrane soaking, hydrochloric acid cleaning agent «1 %w) produces best flux recoveries of 72.7% and 82%, respectively. All permeate effluent analysis, resulted in a suspended solids concentration <3 mgIL and turbidities. < 1 NTU, which both meet Ontario regulation limits.

scholarly journals Design, construction and evaluation OFAN experimental ceramic membrane facility with investigation into fouling control

2021 ◽  
Author(s):  
Sarah Shim
Keyword(s):  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Ceramic Membranes ◽  
Membrane Unit ◽  
Membrane Cleaning ◽  
Fouling Control ◽  
Solids Concentration ◽  
Start Up ◽  
Water And Wastewater ◽  
Design Construction

During the past decade, the growth in membrane research and technology has advanced and multiplied in usage for many industries including water and wastewater. A major limitation of the application is due to membrane fouling. In this work, the construction, start-up calibration and testing of a membrane unit, as well as an examination into the fouling and cleaning aspect of the ceramic membranes are investigated. An aqueous solution containing precipitate is fed to the unit in order to observe fouling behaviour. Effluent wastewater from a bioreactor, CUBEN, is also tested with the unit and membrane cleaning is performed using various chemical agents. For both chemically enhanced backwash (CEB) and membrane soaking, hydrochloric acid cleaning agent «1 %w) produces best flux recoveries of 72.7% and 82%, respectively. All permeate effluent analysis, resulted in a suspended solids concentration <3 mgIL and turbidities. < 1 NTU, which both meet Ontario regulation limits.

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