Influence of molecular size, polarity and charge on the retention of organic molecules by nanofiltration

Bruggen, Bart Van der; Schaep, Johan; Wilms, D.; Vandecasteele, Carlo

doi:10.1016/s0376-7388(98)00326-3

Cited by 744 publications

(358 citation statements)

References 15 publications

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“…Although CBZ is smaller, when these two compounds are both neutral (pH<5.6) SMX is significantly less retained. The authors explained this is due to differences in dipole moment where a higher dipole moment for the SMX causes a lower retention, as argued by other authors for different compounds [24,135,136,42,94,95,146]. Molecules with high dipole moment are directed towards the pore with the side of the dipole with opposite charge closer to the membrane pore, entering more easily into the membrane [24].…”

Section: Charge Repulsionmentioning

confidence: 86%

“…In general it increases with increase of compound MW [14,35,64] and retentions are usually higher than 90% [112,111,138,62,69] for compounds with MW higher than the MWCO of the membrane [14,136,70] (see Figure 4A). MW has been shown to be a good indicator of the retention trend obtained by NF and RO membranes compared to other molecular sizes, e.g.…”

Section: Size Exclusionmentioning

confidence: 96%

“…MW has been shown to be a good indicator of the retention trend obtained by NF and RO membranes compared to other molecular sizes, e.g. Stokes diameter [136]. FIGURE4 However, this trend is not always obeyed and deviations occur in NF and RO (see Figure 4).…”

Section: Size Exclusionmentioning

confidence: 99%

“…estrone at pH>10.3). When this occurs, charge repulsion between the membrane surface charge and the dissociated compound occur enhancing the retention of the xenobiotic [136,63,64,93,94,144,95,145,80]. This effect is especially pronounced with molecules smaller than the pore size of the membrane.…”

Section: Charge Repulsionmentioning

confidence: 99%

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Xenobiotics Removal by Membrane Technology: An Overview

Semiao

Schäfer

2009

Environmental Pollution

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Small molecular weight xenobiotics are compounds of extreme concern in potable water applications due to their adverse human health and environmental effects. However, conventional water treatment processes cannot fully and systematically remove them due to their low concentrations in natural waters and wastewaters. Biological limitation to degrade such compounds is another cause for inefficient removal.Physical barriers like membranes possessing pore sizes smaller than the compounds to be removed emerged as a good solution. Nanofiltration and reverse osmosis proved to be quite effective for xenobiotics removal in potable water production in the Paris purification plant of Méry-sur-Oise. However, even these very narrow pore membrane processes may result in incomplete removal: xenobiotics retention is high but factors such as adsorption, size exclusion and charge repulsion affect unpredictably their retention. The water solutions complexity to be treated renders xenobiotics removal predictions even more difficult due to interactions between xenobiotics and compounds in water.Removal of xenobiotics by microfiltration and ultrafiltration is very low because adsorption on the membrane is the main retention mechanism. Combining those with other processes (e.g. activated carbon) can considerably improve xenobiotics removal.The least studied processes in xenobiotics removal are electrodialysis, membrane distillation and pervaporation. Electrodialysis removal of organic xenobiotics shows a breakthrough through the membrane possibly due to adsorption followed by diffusion. Membrane distillation presents high removal rates of xenobiotics due to the compounds low vapour pressure. For volatile organic xenobiotics or solutions of trace amounts both membrane distillation and pervaporation can be used, xenobiotics interaction with the membrane being the key factor.In this book chapter a thorough synopsis of current knowledge on xenobiotics removal is presented and balanced with recent fundamental studies of underlying mechanisms, informing both the practitioner regarding membrane capabilities for xenobiotics removal and the researcher with the current state-of-art.

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Section: Charge Repulsionmentioning

confidence: 86%

Section: Size Exclusionmentioning

confidence: 96%

Section: Size Exclusionmentioning

confidence: 99%

Section: Charge Repulsionmentioning

confidence: 99%

See 2 more Smart Citations

Xenobiotics Removal by Membrane Technology: An Overview

Semiao

Schäfer

2009

Environmental Pollution

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“…The performance of membranes strongly depends on the surface, sub-layer morphology, and top layer thickness and compactness (Van der Bruggen et al, 1999;Lu et al, 2006;Nigam et al, 2004). The influence of the concentration of OMMT as the additive on the membrane morphology was investigated using SEM apparatus.…”

Section: Effect Of Ommt On the Morphology Of Nanocomposite Membranesmentioning

confidence: 99%

Preparation, characterization and performance of poly( m -phenylene isophthalamide)/organically modified montmorillonite nanocomposite membranes in removal of perfluorooctane sulfonate

Luo

Liu

et al. 2016

Journal of Environmental Sciences

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Nanocomposite membranes containing poly(m-phenylene isophthalamide) (PMIA) and organically modified montmorillonite (OMMT) were prepared by a combination of solution dispersion and wet-phase inversion methods, and the effects of OMMT addition on the properties and performance of fabricated nanofiltration membranes were investigated. The membranes were characterized by contact angle measurements, scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis, and zeta potential.The performance of the membranes was elucidated by the removal of perfluorooctane sulfonate (PFOS) at neutral pH. Increasing OMMT concentration improved the thermal stability and hydrophilicity of the membranes. The permeation and rejection of PFOS were significantly improved. The performance of fabricated nanofiltration membranes in removal of PFOS varied depending on the solute and membrane properties as well as solution conditions. Finally, a comparison between fabricated membranes and a commercial NF membrane (ESNA1-K1, Hydecanme) proved that the OMMT addition is a convenient procedure for producing nanocomposite membranes with superior properties and performance.

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Photocatalytic Membrane Reactors in Water Purification

Molinari

Palmisano

2004

Water Encyclopedia

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Potable water, industrial water, and wastewater are often polluted by toxic organic species. New methods, such as those involving heterogeneous photocatalytic reactions, allow in many cases a complete degradation of organic pollutants to small and non‐noxious species, without using chemicals, avoiding sludge production and its disposal. When combined with membrane separation processes, photocatalytic membrane reactors (PMRs) are obtained. These have some advantages compared to conventional photoreactors. Indeed, confining of the photocatalyst in the reaction environment as a result of the presence of the membrane (separation at molecular level) enables operation with high amounts of catalyst, control of the residence time of the molecules in the reactor, and realization of a continuous process with simultaneous product(s) separation from the reaction environment. The influence of various operating parameters on the photodegradation rate of various pollutants present in aqueous effluents by means of discontinuous and continuous photocatalytic processes are described. The hybrid continuous photoreactor, where a nanofiltration membrane is used, can give a simplification of clean‐up or purification of various types of waters (for industrial, municipal/domestic, and agricultural uses) and no sludge production as well as a saving in chemicals usage. It is expected that these hybrid processes will be considered when plant upgrade is planned and, especially, if sunlight energy can be used for irradiation.

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Influence of molecular size, polarity and charge on the retention of organic molecules by nanofiltration

Cited by 744 publications

References 15 publications

Xenobiotics Removal by Membrane Technology: An Overview

Xenobiotics Removal by Membrane Technology: An Overview

Preparation, characterization and performance of poly( m -phenylene isophthalamide)/organically modified montmorillonite nanocomposite membranes in removal of perfluorooctane sulfonate

Photocatalytic Membrane Reactors in Water Purification

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