Modification of PVDF membranes using polyvinyl alcohol-crosslinked functionalized nano-silica sheets: High flux and antifouling properties for efficient oil-water separation
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引用次数: 0
Abstract
Backgrounds
Oily wastewater is the leading cause of water and environmental pollution, but conventional treatments suffer from complexity and low efficiency, and explicitly deal with oil-in-water emulsions. Polyvinylidene fluoride (PVDF) membranes have shown immense potential for separation applications; however, these membranes rapidly foul during the separation of oily wastewater.
Methods
A simple method is introduced to improve the hydrophilicity of PVDF membranes by decorating their surfaces with acrylic acid-modified nano-silica (NS) nanoparticles, whose surface stability is achieved by crosslinking them with polyvinyl alcohol (PVA). Three distinct oils were employed in this study for oil–water emulsion analysis: vegetable oil, diesel oil, and petroleum ether oil. The antifouling abilities and characterization were elucidated using advanced analytical techniques.
Significant findings
The membrane surface became hydrophilic, and the water contact angle reduced from 64 ± 1.45o to 24.3 ± 1.75o. The NS-PVA-PVDF membrane exhibited the oleophobic behavior underwater, with an underwater oil contact angle of 147.6 ± 2.65o. Under optimized conditions, the NS-PVA-PVDF membranes have shown excellent rejection efficiency for different oil-in-water emulsions, including vegetable oil (99.01± 0.64 %), diesel oil (94.61± 0.26 %), and petroleum ether oil-in-water (84.53 ± 0.85 %) emulsions. For a membrane with a 1:3 ratio of PVA to NS particles, organic foulants like humic acid and dye elucidated better performance with 94.79 ± 1.11 and 92.79 ± 1.41 % removal, respectively, along with the flux recovery ratio of 0.96 and 0.92 for humic acid and dye filtration with irreversible fouling of 0.03 and 0.08, respectively. However, the long-term analysis of the optimum membranes showed an overall stable rejection efficiency of >95 % compared with the pristine membrane. The specific rejection efficiency varied for oil emulsion (44.67–50.14 %), humic acid (59.55–67.75 %), and for dye filtration (61.52–73.5 %). These results verify the potential of the modified NS-PVA-PVDF membrane for oil–water separation for practical applications.
期刊介绍:
Journal of the Taiwan Institute of Chemical Engineers (formerly known as Journal of the Chinese Institute of Chemical Engineers) publishes original works, from fundamental principles to practical applications, in the broad field of chemical engineering with special focus on three aspects: Chemical and Biomolecular Science and Technology, Energy and Environmental Science and Technology, and Materials Science and Technology. Authors should choose for their manuscript an appropriate aspect section and a few related classifications when submitting to the journal online.