One-pot route to synthesize HNTs@PVDF membrane for rapid and effective separation of emulsion-oil and dyes from waste water

• Published in: Journal of hazardous materials 2019-12, Vol.380, p.120865-120865, Article 120865
• Main Authors: Zhou, Liang, He, Yi, Shi, Heng, Xiao, Guoqing, Wang, Shunhui, Li, Zhenyu, Chen, Jingyu
• Format: Article
• Language: English
• Subjects: Dye adsorption; Emulsion separation; HNTs; Special wettability
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2019.120865

[Display omitted] •HNTs decorated PVDF membrane was obtained through a simple dip-coating method.•The modified membrane exhibits high flux and excellent efficiency for separating different oil/water emulsions.•Our membrane can remove dyes from waste water by simply filtering.•The modified membrane shows excellent stability and flux recovery. Water-purification membranes with high water flux, excellent recycling ability, good anti-fouling property, wide range for different oil/water emulsions separation, and strong water-soluble dyes removal ability are highly desirable for water purification but still a challenge to be realized. In this work, we show a simple method to address this challenge, in which halloysite nanotubes (HNTs) have been decorated on the poly (vinylidene fluoride) (PVDF) membrane surface through one-pot method via the aid of KH550 and dopamine. The HNTs@PVDF composite membrane exhibits superhydrophilic and under-water superoleophobic performance. In addition, our membrane can separate wide oil/water emulsions (including surfactant-stabilized and surfactant-free emulsions) from wastewater with high efficiency (>99.65%), outstanding recycle ability with good flux recovery rate (FRR > 95%) and good anti-fouling performance (the underwater oil contact angle (OCA) is 155.8 ± 1.8° with low oil adhesion) and high water flux (7994 ± 150 L m−2 h-1). Interestingly, our membrane also removes different water-soluble dyes (e.g., Congo red, methylene blue, and rhodamine B) from waste water by simply filtering. Those outstanding properties make our membrane hold great potential applications in real-world water purification and environmental protection.