Influence of Foulant Particle Shape on Membrane Fouling in Dead-End Microfiltration

2021 ◽  
Author(s):  
Huang Teik Lay ◽  
Rong Wang ◽  
Jia Wei Chew
Keyword(s):  
Membrane Fouling ◽  
Particle Shape ◽  
Dead End

scholarly journals Potential Pitfalls in Membrane Fouling Evaluation: Merits of Data Representation as Resistance Instead of Flux Decline in Membrane Filtration

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 460
Author(s):  
Bastiaan Blankert ◽  
Bart Van der Bruggen ◽  
Amy E. Childress ◽  
Noreddine Ghaffour ◽  
Johannes S. Vrouwenvelder
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Data Representation ◽  
Strong Impact ◽  
Experimental Conditions ◽  
Permeable Membrane ◽  
Dead End ◽  
Flux Decline ◽  
The Difference ◽  
Filtration Flux

The manner in which membrane-fouling experiments are conducted and how fouling performance data are represented have a strong impact on both how the data are interpreted and on the conclusions that may be drawn. We provide a couple of examples to prove that it is possible to obtain misleading conclusions from commonly used representations of fouling data. Although the illustrative example revolves around dead-end ultrafiltration, the underlying principles are applicable to a wider range of membrane processes. When choosing the experimental conditions and how to represent fouling data, there are three main factors that should be considered: (I) the foulant mass is principally related to the filtered volume; (II) the filtration flux can exacerbate fouling effects (e.g., concentration polarization and cake compression); and (III) the practice of normalization, as in dividing by an initial value, disregards the difference in driving force and divides the fouling effect by different numbers. Thus, a bias may occur that favors the experimental condition with the lower filtration flux and the less-permeable membrane. It is recommended to: (I) avoid relative fouling performance indicators, such as relative flux decline (J/J0); (II) use resistance vs. specific volume; and (III) use flux-controlled experiments for fouling performance evaluation.

scholarly journals Flow and fouling in a pleated membrane filter

2016 ◽  
Vol 795 ◽  
pp. 36-59 ◽  
Author(s):  
P. Sanaei ◽  
G. W. Richardson ◽  
T. Witelski ◽  
L. J. Cummings
Keyword(s):  
Membrane Fouling ◽  
Membrane Filter ◽  
Small Particles ◽  
Porous Support ◽  
Equal Area ◽  
Membrane Filters ◽  
Membrane Pores ◽  
Dead End ◽  
Large Particles ◽  
Membrane Geometry

Pleated membrane filters are widely used in many applications, and offer significantly better surface area to volume ratios than equal-area unpleated membrane filters. However, their filtration characteristics are markedly inferior to those of equivalent unpleated membrane filters in dead-end filtration. While several hypotheses have been advanced for this, one possibility is that the flow field induced by the pleating leads to spatially non-uniform fouling of the filter, which in turn degrades performance. In this paper we investigate this hypothesis by developing a simplified model for the flow and fouling within a pleated membrane filter. Our model accounts for the pleated membrane geometry (which affects the flow), for porous support layers surrounding the membrane, and for two membrane fouling mechanisms: (i) adsorption of very small particles within membrane pores; and (ii) blocking of entire pores by large particles. We use asymptotic techniques based on the small pleat aspect ratio to solve the model, and we compare solutions to those for the closest-equivalent unpleated filter.

scholarly journals Fouling Mechanisms Analysis via Combined Fouling Models for Surface Water Ultrafiltration Process

Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 149 ◽  
Author(s):  
Bin Huang ◽  
Hangkun Gu ◽  
Kang Xiao ◽  
Fangshu Qu ◽  
Huarong Yu ◽  
...  
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Membrane Fouling ◽  
Mechanism Analysis ◽  
Surface Water Treatment ◽  
Dead End ◽  
Cake Layer ◽  
Significant Difference ◽  
Combined Models ◽  
And Control

Membrane fouling is still the bottleneck affecting the technical and economic performance of the ultrafiltration (UF) process for the surface water treatment. It is very important to accurately understand fouling mechanisms to effectively prevent and control UF fouling. The rejection performance and fouling mechanisms of the UF membrane for raw and coagulated surface water treatment were investigated under the cycle operation of constant-pressure dead-end filtration and backwash. There was no significant difference in the UF permeate quality of raw and coagulated surface water. Coagulation mainly removed substances causing turbidity in raw surface water (including most suspended particles and a few organic colloids) and thus mitigated UF fouling effectively. Backwash showed limited fouling removal. For the UF process of both raw and coagulated surface water, the fittings using single models showed good linearity for multiple models mainly due to statistical illusions, while the fittings using combined models showed that only the combined complete blocking and cake layer model fitted well. The quantitative calculations showed that complete blocking was the main reason causing flux decline. Membrane fouling mechanism analysis based on combined models could provide theoretical supports to prevent and control UF fouling for surface water treatment.

Effect of Two Stages Adsorption as Pre-Treatment of Natural Organic Matter Removal in Ultrafiltration Process for Peat Water Treatment

2020 ◽  
Vol 988 ◽  
pp. 114-121 ◽  
Author(s):  
Mahmud ◽  
Muthia Elma ◽  
Erdina Lulu Atika Rampun ◽  
Aulia Rahma ◽  
Amalia Enggar Pratiwi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Optimum Dose ◽  
Operating Pressure ◽  
Filtration Process ◽  
Dead End ◽  
Ultra Filtration ◽  
Pre Treatment ◽  
Two Stages

Natural Organic Matter (NOM) content in peat water is a major problem of membrane fouling in ultrafiltration (UF). For that, two stages adsorption as pre-treatment was employed to minimize the membrane fouling of NOM content. This research was carried out to investigate the effect of two stages adsorption on ultrafiltration performance for NOM removal that remains in peat water. This method was using powdered activated carbon (PAC) dosage of 80, 160, 240, 320, 400, 480, 560, 640, 720, 800, 880 dan 960 mg.L-1. Then, Polysulfone (Psf) material was employed for Ultra filtration process. Membrane was applied in a dead-end mode with various operating pressure (1; 1.5; 2; 2.5; 3 bar). As a results, the optimum dose of PAC was 800 mg L-1 with dosage ratio of 3/4:1/4. Two stages adsorption-UF PSf provided the range from 86.9 to 92.8% of KMnO4 and 74.1-88.1% of UV254. For the experimental condition of 3 bar, the highest flux was achieved up to 39.919 L h-1.m-2.

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.

Development of an Integrated Moving Bed Biofilm Reactor-Membrane Bioreactor for Wastewater Treatment

2013 ◽  
Vol 361-363 ◽  
pp. 611-614 ◽  
Author(s):  
Liang Duan ◽  
Yong Hui Song ◽  
Wei Jiang ◽  
Slawomir W. Hermanowicz
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Biofilm Reactor ◽  
Moving Bed Biofilm Reactor ◽  
Filling Fraction ◽  
Moving Bed ◽  
Operating Modes ◽  
Dead End ◽  
The Media ◽  
Reactor Operating

Development of a MBBR-MBR has been investigated combining a moving bed biofilm reactor with a submerged membrane biomass separation reactor. Treatment efficiencies were found to be high with the production of a consistent high-quality effluent, irrespective of media fill ratio of MBBR or membrane reactor operating modes. There had some obvious fouling in MBR, MBBR and IFAS 3000, while no fouling were detected in IFAS 1500. The great difference indicated the media filling fraction have an important role and effect on membrane fouling. Traditional MBR and IFAS 3000 have more non-flocculating microorganisms in most time due to the mixed liquor suspended solids (MLSS) concentration. There had almost the same MLSS on media surface, independent of the volume of media and the MLSS concentration in each tank. The MBBR had more biomass enriched on membrane surface due to the dead end system.

Integration of ceramic membrane and compressed air-assisted solvent extraction (CASX) for metal recovery

2010 ◽  
Vol 62 (6) ◽  
pp. 1274-1280 ◽  
Author(s):  
Chi-Wang Li ◽  
Chun-Hao Chiu ◽  
Yu-Cheng Lee ◽  
Chia-Hao Chang ◽  
Yu-Hsun Lee ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Removal Efficiency ◽  
Membrane Fouling ◽  
Water Solubility ◽  
Ceramic Membrane ◽  
Metal Removal ◽  
Membrane Surface ◽  
Extraction Process ◽  
Compressed Air ◽  
Dead End

In our previous publications, compressed air-assisted solvent extraction process (CASX) was developed and proved to be kinetically efficient process for metal removal. In the current study, CASX with a ceramic MF membrane integrated for separation of spent solvent was employed to remove and recover metal from wastewater. MF was operated either in crossflow mode or dead-end with intermittent flushing mode. Under crossflow mode, three distinct stages of flux vs. TMP (trans-membrane pressure) relationship were observed. In the first stage, flux increases with increasing TMP which is followed by the stage of stable flux with increasing TMP. After reaching a threshold TMP which is dependent of crossflow velocity, flux increases again with increasing TMP. At the last stage, solvent was pushed through membrane pores as indicated by increasing permeate COD. In dead-end with intermittent flushing mode, an intermittent flushing flow (2 min after a 10-min or a 30-min dead-end filtration) was incorporated to reduce membrane fouling by flush out MSAB accumulated on membrane surface. Effects of solvent concentration and composition were also investigated. Solvent concentrations ranging from 0.1 to 1% (w/w) have no adverse effect in terms of membrane fouling. However, solvent composition, i.e. D2EHPA/kerosene ratio, shows impact on membrane fouling. The type of metal extractants employed in CASX has significant impact on both membrane fouling and the quality of filtrate due to the differences in their viscosity and water solubility. Separation of MSAB was the limiting process controlling metal removal efficiency, and the removal efficiency of Cd(II) and Cr(VI) followed the same trend as that for COD.

scholarly journals PENGARUH PROSES HIBRID KOAGULASI DUA TAHAP DAN MEMBRAN ULTRAFILTRASI POLISULFON TERHADAP PENYISIHAN BAHAN ORGANIK ALAMI AIR GAMBUT

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
Raissa Rosadi ◽  
Mahmud Mahmud ◽  
Chairul Abdi
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Ultrafiltration Membrane ◽  
Hybrid Process ◽  
Optimum Dose ◽  
Two Stage ◽  
Optimum Pressure ◽  
Jar Test ◽  
Dead End

ABSTRAK Penyisihan kandungan bahan organik alami (BOA) pada air gambut dengan menggunakan membran ultrafiltrasi polisulfon mempunyai kendala berupa terjadinya fouling membran. Proses hibrid koagulasi satu tahap dan ultrafiltrasi diketahui hanya mampu menyisihkan kandungan BOA yang bersifat hidrofobik dan sebagian kandungan hidrofilik. Penggunaan koagulasi dua tahap diduga mampu mengurangi potensi fouling pada membran, serta lebih baik dalam menyisihkan kandungan BOA hidrofobik dan hidrofilik. Penelitian ini bertujuan untuk mendapatkan dosis dan tekanan optimum pada proses hibrid koagulasi dua tahap dan UF-PSf dalam menyisihkan kandungan BOA air gambut, serta mengetahui pengaruh praperlakuan koagulasi dua tahap terhadap perubahan nilai fluks pada membran UF-PSf. Proses koagulasi menggunakan alat jar test dengan koagulan Al2(SO4)3. Sistem filtrasi pada membran UF-PSf menggunakan sistem aliran dead-end. Kondisi operasi optimum pada proses hibrid koagulasi dua tahap dan UF-PSf didapatkan pada dosis 175 mg/L dan tekanan filtrasi 3 bar dengan besar penyisihan BOA zat organik KMnO4 dan UV254 berturut-turut sebesar 97,32% dan 96,02%%. Praperlakuan koagulasi dua tahap memberikan pengaruh terhadap nilai fluks yang semakin besar pada proses hibrid koagulasi dua tahap dan UF-PSf. Nilai fluks pada tekanan optimum 3 bar yaitu sebesar 154,84 L/m2.jam. Kata kunci:   Air gambut, bahan organik alami,  fouling membran, koagulasi dua tahap, membran ultrafiltrasi polisulfon. ABSTRACT  Removal of natural organic matter (NOM) on peat water by Polysulfone ultrafiltration membrane (UF-PSf) have some of promblem, namely membrane fouling. Hybrid process of one-stage coagulation and UF-PSf can remove hydrophobic and some hydrophilic content of NOM. Two stage coagulation was allegedly able to decrease membrane fouling, and better to remove hydrophobic and hydrophilic content of NOM. The purpose of this reseach is to find the optimum dose and pressure on two stage coagulation and UF-PSf hybrid process to remove NOM in peat water, and to known the effect of two stage coagulation pretreatment towards flux value changes on UF-PSf membranes. The coagulation process using jar test instrument with Al2(SO4)3 coagulant. The filtration system on the UF-PSf membrane using dead-end flow system. The optimum dose and pressure on hybrid process of two stage coagulation and UF-PSf is 175 mg/L and 3 bar with BOA removal of organic subtances KMnO4 and UV254 respectively amounted to 97,32% and 96,02%. Two stage coagulation pretreatment giving icreasing the flux value on two stage coagulation and UF-PSf hybrid process. The flux value of optimum pressure at 3 bar is 154,84L/m2.hours.  Keywords:    peat water, natural organic matter (NOM), fouling membrane, two stage coagulation,           polysulfone ultrafiltration membrane.

Domestic wastewater treatment by a submerged MBR (membrane bio-reactor) with enhanced air sparging

2003 ◽  
Vol 47 (12) ◽  
pp. 149-154 ◽  
Author(s):  
I.-S. Chang ◽  
S.J. Judd
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Gas Flow ◽  
Domestic Wastewater ◽  
Air Sparging ◽  
Air Jet ◽  
Dead End ◽  
Membrane Tube ◽  
Cake Layer ◽  
Air Lift

The air sparging technique has been recognised as an effective way to control membrane fouling. However, its application to a submerged MBR (Membrane Bio-Reactor) has not yet been reported. This paper deals with the performances of air sparging on a submerged MBR for wastewater treatment. Two kinds of air sparging techniques were used respectively. First, air is injected into the membrane tube channels so that mixed liquor can circulate in the bioreactor (air-lift mode). Second, a periodic air-jet into the membrane tube is introduced (air-jet mode). Their applicability was evaluated with a series of lab-scale experiments using domestic wastewater. The flux increased from 23 to 33 lm−2h−1 (43% enhancement) when air was injected for the air-lift module. But further increase of flux was not observed as the gas flow increased. The Rc/(Rc+Rf), ratio of cake resistance (Rc) to sum of Rc and Rf (internal fouling resistance), was 23%, indicating that the Rc is not the predominant resistance unlike other MBR studies. It showed that the cake layer was removed sufficiently due to the air injection. Thus, an increase of air flow could not affect the flux performance. The air-jet module suffered from a clogging problem with accumulated sludge inside the lumen. Because the air-jet module has characteristics of dead end filtration, a periodic air-jet was not enough to blast all the accumulated sludge out. But flux was greater than in the air-lift module if the clogging was prevented by an appropriate cleaning regime such as periodical backwashing.

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