Chanchan Wang

Dalian University of Technology, Dalian, Liaoning, China

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Publications (7)10.96 Total impact

  • Chanchan Wang, Ranran Feng, Fenglin Yang
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    ABSTRACT: In this work, the surface characteristics of poly(N-vinyl-2-pyrrolidone) (PNVP)-modified nonwoven fabric (NWF) membranes and the effects of the surface characteristics on the membranes antifouling properties were investigated. Effects of grafting time, grafting temperature, and monomer concentration on the grafting degree of PNVP were systematically investigated. The effect of grafting degree on the surface characteristics was also investigated. Scanning electron microscopy (SEM) was used to characterize the structural and morphological changes on the membrane surface. The water contact angles decreased from 113±1.2° to 52±3°, which means that the hydrophilicity of the modified NWF was enhanced with increasing PNVP grafting degree. The surface free energy was calculated, which showed an increase after modification. Static bovine serum albumin (BSA) adsorption experiments were carried out, which showed a decrease of 82.5%. Permeation experiments of water and supernatant solution of active sludge were carried out to determine the antifouling characteristics against the extracellular polymeric substance. Results demonstrated that the modified NWF had higher permeation fluxes and lower flux loss in comparison with the original NWF. Bacterial adhesion on the membrane surface was largely suppressed after the introduction of PNVP.
    Journal of Colloid and Interface Science 02/2011; 357(2):273-9. · 3.17 Impact Factor
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    ABSTRACT: In this paper, a hydrophilic polymer, poly(N-vinyl-2-pyrrolidone) (PNVP), was grafted on the surface of polypropylene non-woven fabric (PP-NWF) membrane via ozone surface activation and surface-initiated atom transfer radical polymerization (ATRP). The grafting degree of PNVP on the membrane surface can be modulated in a wide range through the variation of grafting time. Chemical and morphological changes of the PNVP-modified membrane surface were characterized in detail by Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence spectroscopy and scanning electron microscopy (SEM). The hydrophilicity of the membrane increased upon modification with the water contact angle decreasing from 113.0±1.2° to 52.1±3°. Permeation experiments of water and supernatant solution of active sludge were conducted to evaluate the antifouling property of the PNVP-modified membranes, which results indicated that the modified membranes had higher permeation fluxes with enhanced rejection rates, lower flux loss and better antifouling property than those of the original NWF membrane. Bacterial adhesion on the studied membrane surfaces was also investigated, which showed that bacteria were restrained from growing on PNVP-modified membranes, and adhesion of bacteria was reversible due to the enhanced hydrophilicity.
    Fuel and Energy Abstracts 01/2011; 369(1):233-242.
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    ABSTRACT: To prepare a high flux and antifouling filtration membrane used for submerged membrane bioreactors, non-woven fabric (NWF) was modified by coating chitosan (CS) on both internal and outer surface. Chemical structural and morphological changes were characterized. The changes of surface free energy were monitored by dynamic contact angle, which showed an increase after modification. The CS/NWF composite membranes were found to be with high flux, high effluent quality and excellent antifouling property. The results of fouling resistance distribution indicated that irreversible fouling resistance was decreased by coating CS. Especially, there were fewer gel layers existing on the outer surface. The adsorption of EPS on the NWF membrane internal surface decreased after being coated with CS. Modification improved filtration performance, and made fouling less troublesome and membrane regeneration efficient.
    Bioresource Technology 03/2010; 101(14):5469-74. · 4.75 Impact Factor
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    ABSTRACT: Ultrafiltration (UF) pretreatment and reverse osmosis (RO) were used to treat the blowdown water from circulating cooling water system. The UF product water meets the requirements as RO feed water. To optimize the operation of cooling water system with UF–RO and to ensure a satisfactory cooling water quality within the JRA (Japan Refrigeration and Air Conditioning Industry Association) water standard, a reasonable concentration factor was determined. The results suggest that when the concentration factor was maintained at 1.3, the cooling water could meet the JRA water standard, and the makeup tap water rate was minimal. Calculated Langelier saturation index (LSI) and electrochemical measurements indicate that cooling water had a very slight scaling tendency, and would not cause corrosion. Finally, a comparative cost analysis between applying UF–RO treatment and adding chemical inhibitors in cooling water system was carried out, it is concluded that applying UF–RO in air conditioning circulating cooling water system is more economical.
    Desalination 02/2010; · 3.04 Impact Factor
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    ABSTRACT: Membranes suffer from operational problems due to fouling in water filtration. Fouling is caused by the build-up of chemicals, bioorganic materials, and biofilms at the membrane surface. The focus of this study was the fabrication and characterization of 4-vinyl pyridine grafted polyvinyl alcohol (PVA-g-4VP) and the modifi cation of nonwoven membrane (NWF) for the prevention of bacterial attachment. The graft copolymerization using Ce(IV) as an initiator was carried out in an aqueous solution. With keeping other conditions constant, the optimum conditions were shown as following: [Ce(IV)]=4 mmol/l, [4VP]=0.15 mol/l, reaction temperature=60°C, reaction time=240 min. NWF membranes were modified by coating of PVA-g-4VP with different graft concentrations, and quaternization of the pyridine groups with benzyl bromide. A significant surface enrichment of vinyl pyridine polymer side chains was observed by Fourier transform infrared-attenuated total refl ectance. The permeability of the membrane was reduced after modifi cation. The antimicrobial activity of the modified membrane was measured by 2,3,5-Triphenyl tetrazolium chloride-dehydrogenase. The PVA-g-4VP modified NWF membrane exhibited a higher antimicrobial activity at a higher graft concentration than PVA modified NWF membrane.
    Desalination and Water Treatment - DESALIN WATER TREAT. 01/2010; 18:206-211.
  • Chanchan Wang, Fenglin Yang, Hanmin Zhang
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    ABSTRACT: A facile and effective method, chitosan coating and glutaraldehyde crosslink combined with pretreatment by ozone was developed for endowing non-woven membrane with an antifouling and antibacterial surface. Characteristics of these composite membranes were monitored by Fourier transform infrared-attenuated total reflectance, X-ray photoelectron spectroscopy, water contact angle, and environment scanning electron microscopy. The carbonyl and carboxyl functional groups were generated on the membrane surface after ozone pretreatment. The hydrophilicity of the composite membrane surface was improved. No obvious influence was observed on the structure of the membrane bulk while the membrane surface became smoother after coating. The static adsorption of protein on the composite membrane significantly decreased comparing with the original membrane. The relatively higher flux recovery ratio of permeation flux for protein solution filtration was obtained for the composite membrane. Furthermore, antibacterial properties of the composite membranes were investigated by staining and growth inhibition. The results indicated that there were less bacteria attached onto the composite membranes. The composite membrane was thus demonstrated to be very effective in preventing the formation of biofilm, especially for the membrane with glutaraldehyde crosslink.
    Separation and Purification Technology - SEP PURIF TECHNOL. 01/2010; 75(3):358-365.
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    ABSTRACT: This paper introduces a versatile approach for the modification of terylene microporous membrane by PVA-MS layer-by-layer self-assembling to improve its filterability. The preparation conditions including filtration time of the first HTAB layer, reaction time and bilayer number were investigated. The results suggested that suitable filtration time of the first HTAB layer was 8min and the reaction time was 10min with suitable HTAB/PVA-MS bilayer numbers. Membrane chemistry, morphological changes and hydrophilicity of the composite membrane were characterized in details by FTIR-ATR spectroscopy, scanning electron micrograph and water dynamic contact angle measurements. Results revealed that PVA-MS could be adsorbed mainly on the surface of the terylene microporous membrane and dynamic contact angle on the terylene microporous membrane surface decreased with the increase of bilayer numbers indicating an enhanced hydrophilicity for the modified terylene microporous membrane. Backwash experiments of composite membranes exhibited much higher stability of the HTAB/PVA-MS active layer. The permeation flux of activated sludge was measured to evaluate the anti-fouling property of composite membranes, and the results showed an enhancement of anti-fouling property of modified composite membranes.
    Microporous and Mesoporous Materials - MICROPOROUS MESOPOROUS MAT. 01/2010; 132(1):72-79.

Publication Stats

7 Citations
63 Downloads
284 Views
10.96 Total Impact Points

Institutions

  • 2010–2011
    • Dalian University of Technology
      • • Department of Environmental Science and Technology
      • • School of Environmental and Biological Science and Technology
      Dalian, Liaoning, China