Investigation of flow next to membrane walls

Gimmelshtein, Margarita; Semiat, Raphael

doi:10.1016/j.memsci.2005.04.033

Cited by 69 publications

(38 citation statements)

References 42 publications

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“…All experiments were performed at room temperature. Since the permeate flow in RO is very small compared to the crossflow velocity [13], the cell was operated without permeation or even a membrane. Experiments confirmed that the presence of a polyamide DOW SW30HR membrane did not influence the bubble size or shape.…”

Section: Setupmentioning

confidence: 99%

Bubbles in spacers: Direct observation of bubble behavior in spacer filled membrane channels

Willems

Kemperman

Lammertink

et al. 2009

Journal of Membrane Science

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Section: Setupmentioning

confidence: 99%

Bubbles in spacers: Direct observation of bubble behavior in spacer filled membrane channels

Willems

Kemperman

Lammertink

et al. 2009

Journal of Membrane Science

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“…In particular, many deposits in regions underneath or close to the spacer strands had a thickness of about 90 μm or more, as illustrated in Figure 2(a), whereas those located further away were thinner and had a thickness A major objective of using the feed spacer is to promote eddy mixing which increases mass transfer and reduces concentration polarization (Belfort and Guter, 1972). Whilst turbulence is created between the spacer strands, it is also known that the spacer may promote excessive particle precipitation in regions close to the strands (Gimmelshtein and Semiat, 2005). This undesirable effect is evident in the present study from the observation of the thick deposits in these regions.…”

Section: General Observations By Optical Microscopymentioning

confidence: 99%

An autopsy study of a fouled reverse osmosis membrane element used in a brackish water treatment plant

et al. 2007

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The fouling of a spiral wound RO membrane after nearly one year of service in a brackish water treatment plant was investigated using optical and electron microscopic methods, FTIR and ICP-AES. Both the top surface and the cross-section of the fouled membrane were analysed to monitor the development of the fouling layer. It has been found that the extent of fouling was uneven across the membrane surface with regions underneath or in the vicinity of the strands of the feed spacer being more severely affected. The fouling appeared to have developed through different stages. In particular, it consisted of an initial thin fouling layer of an amorphous matrix with embedded particulate matter. The amorphous matrix comprised organic-Al-P complexes and the particulate matter was mostly aluminium silicates.Subsequently, as the fouling layer reached a thickness of about 5 to 7 μm, further amorphous material, which is suggested to include extracellular polymeric substances such as polysaccharides, started to deposit on top of the existing fouling layer. This secondary amorphous material did not seem to contain any particulate matter nor any inorganic elements 1 25 26 27 28 29 within it, but acted as a substrate upon which aluminium silicate crystals grew exclusively in the absence of other foulants, including natural organic matter (NOM).

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“…Membrane module "autopsies" have been used to study membrane/spacer fouling [5,6], where module is dissected open and the internal surface examined for fouling. Direct optical techniques have also been applied in the study of membrane spacers and fouling [16][17][18][19]. Vrouwenvelder et al designed a flow cell with transparent cover to study fouling within membrane/spacer filled channels [17].…”

Section: Introductionmentioning

confidence: 99%