In order to protect the environment, it is important that oily industrial wastewater is degreased before discharging. Membrane filtration is generally preferred for separation of oily wastewater as it does not require any specialised chemical knowledge, and also for its ease of processing, energy efficiency and low maintenance costs. In the present work, hybrid polyacrylonitrile (PAN) nanofibrous membranes were developed for oily wastewater filtration. Membrane surface modification changed nitrile groups on the surface into carboxylic groups, which improve membrane wettability. Subsequently, TiO2 nanoparticles were grafted onto the modified membranes to increase flux and permeability. Following alkaline treatment (NaOH, KOH) of the hydrolysed PAN nanofibres, membrane water permeability increased two- to eight-fold, while TiO2 grafted membrane permeability increase two- to thirteen-fold, compared to unmodified membranes. TiO2 grafted membranes also displayed amphiphilic properties and a decrease in water contact angle from 78.86° to 0°. Our results indicate that modified PAN nanofibrous membranes represent a promising alternative for oily wastewater filtration.

Centre for Nanomaterials Advanced Technology and Innovation Technical University of Liberec Studentska 1402 2 46117 Liberec Czech Republic

Faculty of Mechatronics Technical University of Liberec Studentska 1402 2 46117 Liberec Czech Republic

Zobrazit více v PubMed

Goh P.S., Ong C.S., Ng B.C., Ismail A.F. 5—Applications of Emerging Nanomaterials for Oily Wastewater Treatment. In: Ahsan A., Ismail A.F., editors. Nanotechnology in Water and Wastewater Treatment. Elsevier; Amsterdam, The Netherlands: 2019. pp. 101–113. Micro and Nano Technologies.

Scharnagl N., Buschatz H. Polyacrylonitrile (PAN) Membranes for Ultra- and Microfiltration. Desalination. 2001;139:191–198. doi: 10.1016/S0011-9164(01)00310-1. DOI

Wang J., Yue Z., Economy J. Solvent Resistant Hydrolyzed Polyacrylonitrile Membranes. Sep. Sci. Technol. 2009;44:2827–2839. doi: 10.1080/01496390903135923. DOI

Bryjak M., Hodge H., Dach B. Modification of Porous Polyacrylonitrile Membrane. Angew. Makromol. Chem. 1998;260:25–29. doi: 10.1002/(SICI)1522-9505(19981101)260:1<25::AID-APMC25>3.0.CO;2-K. DOI

Sabantina L., Mirasol J.R., Cordero T., Finsterbusch K., Ehrmann A. Investigation of Needleless Electrospun PAN Nanofiber Mats. AIP Conf. Proc. 2018;1952:020085. doi: 10.1063/1.5032047. DOI

Großerhode C., Wehlage D., Grothe T., Grimmelsmann N., Fuchs S., Hartmann J., Mazur P., Reschke V., Siemens H., Rattenholl A., et al. Investigation of Microalgae Growth on Electrospun Nanofiber Mats. AIMS Bioeng. 2017;4:376. doi: 10.3934/bioeng.2017.3.376. DOI

Kohn S., Wehlage D., Juhász Junger I., Ehrmann A. Electrospinning a Dye-Sensitized Solar Cell. Catalysts. 2019;9:975. doi: 10.3390/catal9120975. DOI

Grothe T., Wehlage D., Boehm T., Remche A., Ehrmann A. Needleless Electrospinning of PAN Nanofibre Mats. Tekstilec. 2017;60:290–295. doi: 10.14502/Tekstilec2017.60.290-295. DOI

Blachowicz T., Ehrmann A. Most Recent Developments in Electrospun Magnetic Nanofibers: A Review. J. Eng. Fibers Fabr. 2020;15:1558925019900843. doi: 10.1177/1558925019900843. DOI

Blachowicz T., Ehrmann A. Conductive Electrospun Nanofiber Mats. Materials. 2019;13:152. doi: 10.3390/ma13010152. PubMed DOI PMC

Yalcinkaya F., Siekierka A., Bryjak M. Surface Modification of Electrospun Nanofibrous Membranes for Oily Wastewater Separation. RSC Adv. 2017;7:56704–56712. doi: 10.1039/C7RA11904F. DOI

Wang Y.-X., Li Y.-J., Yang H., Xu Z.-L. Super-Wetting, Photoactive TiO2 Coating on Amino-Silane Modified PAN Nanofiber Membranes for High Efficient Oil-Water Emulsion Separation Application. J. Membr. Sci. 2019;580:40–48. doi: 10.1016/j.memsci.2019.02.062. DOI

Sabantina L., Böttjer R., Wehlage D., Grothe T., Klöcker M., García-Mateos F.J., Rodríguez-Mirasol J., Cordero T., Ehrmann A. Morphological Study of Stabilization and Carbonization of Polyacrylonitrile/TiO2 Nanofiber Mats. J. Eng. Fibers Fabr. 2019;14:1558925019862242. doi: 10.1177/1558925019862242. DOI

Zhang J., Pan X., Xue Q., He D., Zhu L., Guo Q. Antifouling Hydrolyzed Polyacrylonitrile/Graphene Oxide Membrane with Spindle-Knotted Structure for Highly Effective Separation of Oil-Water Emulsion. J. Membr. Sci. 2017;532:38–46. doi: 10.1016/j.memsci.2017.03.004. DOI

Shakiba M., Nabavi S.R., Emadi H., Faraji M. Development of a Superhydrophilic Nanofiber Membrane for Oil/Water Emulsion Separation via Modification of Polyacrylonitrile/Polyaniline Composite. Polym. Adv. Technol. 2020 doi: 10.1002/pat.5178. DOI

Pérez-Álvarez L., Ruiz-Rubio L., Moreno I., Vilas-Vilela J.L. Characterization and Optimization of the Alkaline Hydrolysis of Polyacrylonitrile Membranes. Polymers. 2019;11:1843. doi: 10.3390/polym11111843. PubMed DOI PMC

Xu B., Wang X., Lu Y. Surface Modification of Polyacrylonitrile-Based Carbon Fiber and Its Interaction with Imide. Appl. Surf. Sci. 2006;253:2695–2701. doi: 10.1016/j.apsusc.2006.05.044. DOI

Boyraz E., Yalcinkaya F., Hruza J., Maryska J. Surface-Modified Nanofibrous PVDF Membranes for Liquid Separation Technology. Materials. 2019;12:2702. doi: 10.3390/ma12172702. PubMed DOI PMC

Kujawski W., Adamczak P., Narebska A. A Fully Automated System for the Determination of Pore Size Distribution in Microfiltration and Ultrafiltration Membranes. Sep. Sci. Technol. 1989;24:495–506. doi: 10.1080/01496398908049787. DOI

Yalcinkaya F., Hruza J. Effect of Laminating Pressure on Polymeric Multilayer Nanofibrous Membranes for Liquid Filtration. Nanomaterials. 2018;8:272. doi: 10.3390/nano8050272. PubMed DOI PMC

Wang Z., Lin S. Membrane Fouling and Wetting in Membrane Distillation and Their Mitigation by Novel Membranes with Special Wettability. Water Res. 2017;112:38–47. doi: 10.1016/j.watres.2017.01.022. PubMed DOI

Wang Z.-G., Wan L.-S., Xu Z.-K. Surface Engineerings of Polyacrylonitrile-Based Asymmetric Membranes towards Biomedical Applications: An Overview. J. Membr. Sci. 2007;304:8–23. doi: 10.1016/j.memsci.2007.05.012. DOI

Aliotta F., Calandra P., Salvato G. Octanoic Acid as a Novel Solvent for Low Electric Field Electrorheological Fluids. ScienceJet. 2013;2:38.

Shriver D.F., Atkins P.W. Inorganic Chemistry. 3rd ed. W.H. Freeman and Co.; New York, NY, USA: 1999.

Zhaowen C., Xu W. Properties of Partially Hydrolyzed PAN Fibers. Front. Chem. Chin. 2009;4:110–113.

Abuzade R.A., Zadhoush A., Gharehaghaji A.A. Air Permeability of Electrospun Polyacrylonitrile Nanoweb. J. Appl. Polym. Sci. 2012;126:232–243. doi: 10.1002/app.36774. DOI

Banerjee S., Dionysiou D.D., Pillai S.C. Self-Cleaning Applications of TiO2 by Photo-Induced Hydrophilicity and Photocatalysis. Appl. Catal. B Environ. 2015;176–177:396–428. doi: 10.1016/j.apcatb.2015.03.058. DOI

Yalcinkaya F., Siekierka A., Bryjak M. Preparation of Fouling-Resistant Nanofibrous Composite Membranes for Separation of Oily Wastewater. Polymers. 2017;9:679. doi: 10.3390/polym9120679. PubMed DOI PMC

Yalcinkaya F., Yalcinkaya B., Hruza J., Hrabak P. Effect of Nanofibrous Membrane Structures on the Treatment of Wastewater Microfiltration. Sci. Adv. Mater. 2017;9 doi: 10.1166/sam.2017.3027. DOI

Fane A.G., Fell C.J.D., Kim K.J. The Effect of Surfactant Pretreatment on the Ultrafiltration of Proteins. Desalination. 1985;53:37–55. doi: 10.1016/0011-9164(85)85051-7. DOI

Grieves R.B., Bhattacharyya D., Schomp W.G., Bewley J.L. Membrane Ultrafiltration of a Nonionic Surfactant. AIChE J. 1973;19:766–774. doi: 10.1002/aic.690190414. DOI

Bhattacharyya D., Jumawan A.B., Grieves R.B., Witherup S.O. Ultrafiltration of Complex Wastewaters: Recycling for Nonpotable Use. J. (Water Pollut. Control Fed.) 1978;50:846–861.

Jönsson A.-S., Jönsson B. The Influence of Nonionic and Ionic Surfactants on Hydrophobic and Hydrophilic Ultrafiltration Membranes. J. Membr. Sci. 1991;56:49–76. doi: 10.1016/0376-7388(91)85015-W. DOI

Sourirajan S., Sirianni A.F. Membrane Separation Studies with Some Polyoxyethylated Alkylphenols in Aqueous Solution. Ind. Eng. Chem. Prod. Res. Dev. 1966;5:30–34. doi: 10.1021/i360017a006. DOI

Zhang G., Meng H., Ji S. Hydrolysis Differences of Polyacrylonitrile Support Membrane and Its Influences on Polyacrylonitrile-Based Membrane Performance. Desalination. 2009;242:313–324. doi: 10.1016/j.desal.2008.05.010. DOI

Shuai Q., Yang X., Luo Y., Tang H., Luo X., Tan Y., Ma M. A Superhydrophobic Poly(Dimethylsiloxane)-TiO2 Coated Polyurethane Sponge for Selective Absorption of Oil from Water. Mater. Chem. Phys. 2015;162:94–99. doi: 10.1016/j.matchemphys.2015.05.011. DOI

Gao S., Huang J., Li S., Liu H., Li F., Li Y., Chen G., Lai Y. Facile Construction of Robust Fluorine-Free Superhydrophobic TiO2@fabrics with Excellent Anti-Fouling, Water-Oil Separation and UV-Protective Properties. Mater. Des. 2017;128:1–8. doi: 10.1016/j.matdes.2017.04.091. DOI

Wang R., Hashimoto K., Fujishima A., Chikuni M., Kojima E., Kitamura A., Shimohigoshi M., Watanabe T. Photogeneration of Highly Amphiphilic TiO2 Surfaces. Adv. Mater. 1998;10:135–138. doi: 10.1002/(SICI)1521-4095(199801)10:2<135::AID-ADMA135>3.0.CO;2-M. DOI

Wang R., Hashimoto K., Fujishima A., Chikuni M., Kojima E., Kitamura A., Shimohigoshi M., Watanabe T. Light-Induced Amphiphilic Surfaces. Nature. 1997;388:431–432. doi: 10.1038/41233. DOI

Yu Q., Zhou L., Su Y., Wu H., You X., Shen J., Zhang R., Jiang Z. Assembly of Self-Cleaning Perfluoroalkyl Coating on Separation Membrane Surface. Appl. Surf. Sci. 2019;496:143674. doi: 10.1016/j.apsusc.2019.143674. DOI

Zhao X., Su Y., Chen W., Peng J., Jiang Z. Grafting Perfluoroalkyl Groups onto Polyacrylonitrile Membrane Surface for Improved Fouling Release Property. J. Membr. Sci. 2012;415–416:824–834. doi: 10.1016/j.memsci.2012.05.075. DOI

Ying Z.-Y., Shao Z.-D., Wang L., Cheng X., Zheng Y.-M. Sol–Gel SiO2 on Electrospun Polyacrylonitrile Nanofiber for Efficient Oil-in-Water Emulsion Separation. J. Mater. Sci. 2020;55:16129–16142. doi: 10.1007/s10853-020-05155-8. DOI

Wang J., Hou L., Yan K., Zhang L., Yu Q.J. Polydopamine Nanocluster Decorated Electrospun Nanofibrous Membrane for Separation of Oil/Water Emulsions. J. Membr. Sci. 2018;547:156–162. doi: 10.1016/j.memsci.2017.10.028. DOI

Islam M.S., McCutcheon J.R., Rahaman M.S. A High Flux Polyvinyl Acetate-Coated Electrospun Nylon 6/SiO2 Composite Microfiltration Membrane for the Separation of Oil-in-Water Emulsion with Improved Antifouling Performance. J. Membr. Sci. 2017;537:297–309. doi: 10.1016/j.memsci.2017.05.019. DOI

Chemical Cleaning Process of Polymeric Nanofibrous Membranes