The enhancement of dye filtration performance and antifouling properties in amino-functionalized bentonite/polyvinylidene fluoride mixed matrix membranes

Abstract

Trade-off issue and membrane fouling remain two major issues in the utilization of membrane technology for the water treatment due to reduced membrane permeability and lifetime. In our study, we employed 3-aminopropyltriethoxysilane modified bentonite (BNTAPS) as an anti-fouling modifier to prepare polyvinylidene fluoride (PVDF)-based membranes via the phase inversion method. The effects of BNTAPS concentration on the physical, mechanical, morphological, and filtration performance of the hybrid membranes have been investigated. It was found that the addition of BNTAPS improved the hydrophilicity of the membrane revealed by the decreased water contact angle. Consequently, the pure water flux of PVDF membrane containing 0.5% BNTAPS (PVDF/BNTAPS0.5%) increased to 35.5 L m−2 h−1. Moreover, the PVDF/BNTAPS membrane showed a smaller pore diameter and porosity compared to pristine PVDF. The membrane performance evaluation was carried out using cationic and anionic dyes, i.e., methylene blue (MB) and acid yellow (AY17), respectively. Our study revealed that the rejection of each dye was slightly increased for the PVDF/BNTAPS0.5%. However, the flux recovery rate of the PVDF/BNTAPS membrane significantly improved, which directly prolonged the membrane lifetime.

Keywords

• PVDF
• Silylation
• Water treatment
• Methylene blue
• Acid yellow