Nanofiltration for water and wastewater treatment – a mini review

Shon, Ho Kyong; Phuntsho, Sherub; Chaudhary, D. S.; Vigneswaran, S.; Cho, J.

doi:10.5194/dwesd-6-59-2013

Cited by 21 publications

(18 citation statements)

References 44 publications

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“…Nanofiltration is a pressure‐driven membrane process for liquid‐phase separation and its properties lie between those of non‐porous reverse osmosis membranes and porous ultrafiltration membranes (Shon et al . ). The application of nanofiltration for concentration of fruit or vegetable juices and extracts is also advantageous in terms of cost, since the process is less energy‐consuming than membrane technologies such as reverse osmosis and osmotic evaporation.…”

Section: Introductionmentioning

confidence: 97%

Concentration of Polyphenolic Compounds in Blackberry (Rubus Adenotrichos Schltdl.) Juice by Nanofiltration

Acosta

Vaillant

Pérez

et al. 2016

J Food Process Engineering

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Nanofiltration membranes with molecular weight cut-off around 200 Da were evaluated to concentrate anthocyanins and ellagitannins in a blackberry juice. Temperature was 308C and cross-flow velocity 0.3 m/s. Transmembrane pressures varied from 0.5 to 3 MPa. At volumetric reduction ratio (VRR) of 1, higher transmembrane pressures caused an increase of permeate flux and of retention of total anthocyanins (>94%) and total soluble solids (44-97%). Every membrane presented 100% of total ellagitannin retention. Results were represented using the solution-diffusion model. NF270 membrane at 3 MPa showed the highest potential for concentration of blackberry's main polyphenolic compounds (highest permeate flux and solute retention). Nevertheless, a simulated increase of VRR showed that permeate flux declined as the concentration of the feed solution increased. NF270 membrane may also be of interest to deacidify the juice, since at high pressures, sugars were completely retained and retention of acids was under 90%. PRACTICAL APPLICATIONSThe concentration of phytochemicals by means of membrane technologies is of interest to the food industry, because the operations replace evaporation processes that are energy-intensive and use high temperatures that can reduce the compounds' bioactivities. The results presented in this study may be valuable for processors that aim to concentrate fruit juices and extracts enriched with phytochemicals (such as anthocyanins and ellagitannins), by using nanofiltration. Furthermore, results show that nanofiltration membranes at specific operating conditions may not only be employed to concentrate, but also to deacidify fruit juices and extracts. This operation provides advantages when compared to other technologies such as calcium salt precipitation, ion-exchange resins and electrodialysis.

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Section: Introductionmentioning

confidence: 97%

Concentration of Polyphenolic Compounds in Blackberry (Rubus Adenotrichos Schltdl.) Juice by Nanofiltration

Acosta

Vaillant

Pérez

et al. 2016

J Food Process Engineering

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“…This can be attributed to the fluctuation of polymer chains being suppressed in the crosslinked polymer networks, which is also supported by the enhanced film stiffness. Membranes comprising crosslinked poly- p -xylylene nanofilms fabricated by the CVD polymerization of two monomers show outstanding separation performance in water with water permeance of the same level of water permeance as those of commercial NF membranes (30–80 L m −2 hr −1 MPa −1 ) 21 , 29 .…”

Section: Selective Solvent Permeance Of Poly- P -Xmentioning

confidence: 99%

Selective Blocking Property of Microporous Polymer Membranes Fabricated by Chemical Vapor Deposition

Shii

Hatori

Yokota

et al. 2017

Sci Rep

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Poly-p-xylylene films have been utilized as protective and barrier layers for gases and solvents on electronic and implantable devices. Here we report a new approach to create highly permeable and selective nanofiltration membranes coated with microporous poly-p-xylylene nanofilms fabricated through a dry chemical vapor deposition process by using [2.2]paracyclophanes derivatives on ultrafiltration membranes. The introduction of crosslinking points into rigid poly-p-xylylenes enhanced microporosity and mechanical strength due to insufficient packing and depression of structural relaxation among polymer chains in three-dimensional networks. Crosslinked nanofilms with thicknesses down to 50 nm showed outstanding permeability for water and alcohols at a pressure difference of 0.5 MPa and exhibited higher rejection ratios for water-soluble organic dyes than non-crosslinked nanofilms. Poly-p-xylylene nanofilms also showed an excellent blocking property for non-polar organic solvent permeation through specific interaction of hydrophilic pores with organic solvents.

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“…In general, several types of filtration technology (physical methods) have been widely used for wastewater and textile effluents treatment, such as membrane-filtration processes (microfiltration, ultrafiltration, nanofiltration, and reverse osmosis) and adsorption techniques [23,[29][30][31][32][33]. However, major disadvantages of the membrane-filtration processes are that they are only applied in small wastewater flow rate, require higher production cost of membrane and cost of periodic replacement, require high working pressure to push the wastewater flow through membrane filtration, and are unable to reduce dissolved solid content.…”

Section: Dye Removal Techniquesmentioning

confidence: 99%

An Overview: Recent Development of Titanium Oxide Nanotubes as Photocatalyst for Dye Degradation

Lai

Juan

et al. 2014

International Journal of Photoenergy

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Today, organic dyes are one of the largest groups of pollutants release into environment especially from textile industry. It is highly toxic and hazardous to the living organism; thus, the removal of these dyes prior to discharge into the environment is essential. Varieties of techniques have been employed to degrade organic dyes and heterogeneous photocatalysis involving titanium dioxide (TiO2) appears to be the most promising technology. In recent years, TiO2nanotubes have attracted much attention due to their high surface area and extraordinary characteristics. This paper presents a critical review of recent achievements in the modification of TiO2nanotubes for dye degradation. The photocatalytic activity on dye degradation can be further enhanced by doping with cationic or anionic dopant.

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Nanofiltration for water and wastewater treatment – a mini review

Cited by 21 publications

References 44 publications

Concentration of Polyphenolic Compounds in Blackberry (Rubus Adenotrichos Schltdl.) Juice by Nanofiltration

Concentration of Polyphenolic Compounds in Blackberry (Rubus Adenotrichos Schltdl.) Juice by Nanofiltration

Selective Blocking Property of Microporous Polymer Membranes Fabricated by Chemical Vapor Deposition

An Overview: Recent Development of Titanium Oxide Nanotubes as Photocatalyst for Dye Degradation

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